MULTIAXIAL STRESSES (STATES OF STRESS AND STRAIN) The octahedral planes are also of importance in yielding prediction and fatigue analysis. principal axes of stress. Shear Strength of Soils INCLINATION OF FAILURE PLANE PRINCIPAL STRESSES Where: ´ 1 = Major Principal Stress ´ 3 = Minor Principal Stress ´ 1 ´ 1 ´ 3 ´ 3 Normal Stress ( ´) Shear Stress ( ) MC Failure Criteria c´ a ´ ´ 3 1 Normal Stress ( ´) Inclination of Failure Plane with Major Principal Plane Figure 8. The failure of the pipe in two halves in fact is possible across any plane, which contains diameter and axis of the pipe. Question: Consider State Of Stress As Shown Below. SOLUTION ave. sachin says. Enter values in the upper left 2x2 positions and rotate in the 1-2 plane to perform transforms in 2-D. Negative shear stress τ′ = positive shear stress t τ′ is the complementary shear stress to applied shear stress (numerically) t, acting at an angle of 90°. MECHANICS OF MATERIALS Edition Beer • Johnston • DeWolf 7 - 2 Transformations of Stress and Strain Introduction Transformation of Plane Stress Principal Stresses Maximum Shearing Stress Example 7. Stresses in oblique plane In real life stresses does not act in normal direction but rather in inclined planes. If the axial force force on a rectangular bar is decreases, the normal stress will ?. Determine the orientations of the principal planes and the magnitudes of the principal stresses with correct senses. The external work done by the application of. tan 2u s =-As x - s yB>2 t xy =-(-22. Identify the stress. 4) The angle between the major principal stress plane and the horizontal plane (ψ) is: x zx σ σ τ ψ − = 1 tan (1. Research the job description, education, licensing, and other principal requirements to determine whether this is the right career for you. Most problems in sheet metal forming come from a bad control of holding, Principal strain plane A line of plane stress, where. Transformation of Stresses and Strains stressestothesenewx0y0planes. 05° (as shown in Fig. Figure 1 illustrates three commonly used strain gage rosette configurations. The system will have one reaction dominate until the offsetting changes allow the rates of the forward and reverse reactions to be equal again (reestablishing equilibrium). • The maximum normal stress occurs when the reference plane is perpendicular to the member axis, 0 0 m A P • The maximum shear stress occurs for a plane at + 45 o with respect to the axis, 0 2 0 sin45 cos45 A P A P m Maximum Stresses cos sin cos 0 2 0 A P A P • Normal and shearing stresses on an oblique plane. There are always three extreme-value shear stresses. Federal Aviation Administration. 3 MPa σ 2 = -15 - 67. Known: A machine frame made of steel having known Sy and Ssy is loaded in a test fixture. Definition 1: Let X = [x i] be any k × 1 random vector. Three‐dimensional Discrete Element Method simulations have been performed to study the deformation of cross‐anisotropic granular materials under principal stress rotation (PSR), for rotation planes oriented at different angles θ with respect to the bedding plane. principal planes. The maximum in-plane shear stress is and the maximum shear angle is. the problem for the deformation of a cylinder with diameter D in contact with a plane over a length L and under the action of force the approach where a solution is generated from the general three-dimensional case of curved bodies by assigning the plane surface a radius of curvature. None of the above. acting on any plane, Fig. Assume the plane stress conditions. At the bottom of the tank the tensile stresses will be larger, so the bottom mid-point is critical. Plane Stress and Plane Strain Equations 2. The principal stresses σ Contact Stresses and Deformations 7-20 Center Displacement Depending on Material Combination 0 1020 30 40 506070 80 90 100 0 1. 22 Principal Stresses and Maximum ENES 220 ©Assakkaf Shearing Stress Location of the Plane of Principal Stresses 2 tan 2 1 1 − = − x y xy p σ σ τ θ (22b) LECTURE 22. 3 Principal Stresses and Maximum In-Plane Shear Stresses In-plane Principal Stresses - หน วยแรงต ั้งฉากท ี่มีค าสูงสุดและน อยสุด ที่เกดขิึ้นบน stress element ที่ถูกกระท ําโดยสภาวะของหน วย. Classical longitudinal tomography used this principle. You offer 4 types of meat (ham, turkey, roast beef, and pastrami) and 3 types of bread (white, wheat, and rye). Principal Directions, Principal Stress: The normal stresses (s x' and s y') and the shear stress (t x'y') vary smoothly with respect to the rotation angle q, in accordance with the coordinate transformation equations. A plane is ﬂat. They also are simply the components of T: T1=Tn1, T2=Tn2, and T3=Tn3. Determine the principal planes and the principal stresses for the state of plane stress resulting from the superposition of the two states of stress shown. EXPECTED OUTCOMES: In-Plane Principal Stresses. The resulting governing equation is then solvable. Numerous solutions to plane strain and plane stress problems can be determined through the use of a particular stress function technique. (This stress will also vary in the radial direction & not with ‘Ѳ’ as in tangential stress case. 30 and _ + 450 21. 2 Types of Friction 2. Plane surveying. Bragg Consider a set of Nf 1 equidistant atomic planes of spacing d, and a monochromatic plane X-wave falling on it at a glancing angle 0 (Fig. Location of Maximum Shear Stress Plane. Structural Geology is perhaps one of the hardest subjects for beginning geology students to learn. 8-1 Definitions. Show the result on an element located at this point. This drawing is of a lower hemisphere plot but the results for the upper hemisphere are similar. At this pressure, the principal stresses are σ 1 = 13000psi and σ 2 = 430psi. The normal stress components in the principal planes are the. σ 1, σ 2 and σ 3 are the principal stresses such that σ 1 > σ 2 > σ 3 1. Method of Obtaining Magnitude and Direction of Principal Stress (Rosette Analysis) Generally, if the direction of principal stress is uncertain in structure stress measurement, a triaxial rosette gage is used and measured strain values are calculated in the following equation to find the direction of the principal stress. The principal stresses and the stress invariants are important parameters that are used in failure criteria, plasticity, Mohr's circle etc. d) Determine the maximum shearing stress and the corresponding normal stress. 3 , takes the form of a real symmetric three-dimensional matrix. Plane Stress Problems Plane Stress and Plane Strain Equations The two-dimensional element is extremely important for: (1) Plane stress analysis, which includes problems such as plates with holes, fillets, or other changes in Recall, the relationships for principal stresses in two-. planes which bound element A. Based on the Elastic-plastic stress-strain relationship for soil and test data under the plane strain condition, it is assumed that the. 6 For the given state of stress, determine (a) the principal planes, (b) the principal stresses- = IOMPa 15) = 50 MPa = 0. 8 Horizontal Force Required to Move the Body 2. ASEN 3112 - Structures Principal Stresses: Terminology The max and min values taken by the in-plane normal stress σ when viewed as a function of the angle θ are called principal stresses. 100 MPa 1 48 MPa. Recalling there will be no traverse shear stress due to weight at the bottom fiber, the axial stresses are to be taken as principal stresses. Le Châtelier's Principle states that if you apply a stress to a system at equilibrium, the equilibrium will shift in the direction that will remove the stress. shear stress theory. Determine also the normal and tangential stresses on plane AC. Shear Strength of Soils INCLINATION OF FAILURE PLANE PRINCIPAL STRESSES Where: ´ 1 = Major Principal Stress ´ 3 = Minor Principal Stress ´ 1 ´ 1 ´ 3 ´ 3 Normal Stress ( ´) Shear Stress ( ) MC Failure Criteria c´ a ´ ´ 3 1 Normal Stress ( ´) Inclination of Failure Plane with Major Principal Plane Figure 8. Practical examples of principal planes in actual components will also be discussed. Similar to finding transformed stresses, we draw lines from the pole to where τ = 0, or the two “x-intercepts” on the circle. - Second principal plane: For a bundle of rays incident on a lens parallel to its axis, when the incident and emergent rays are projected ahead and back, the points of intersection lie in a common plane known as the second (or secondary) principal plane (Figure (b)). σ 1, σ 2 and σ 3 are the principal stresses such that σ 1 > σ 2 > σ 3 1. 2 are the two in-plane principal strains. 100 Chapter 3 Two-Dimensional Problems in Elasticity FIGURE 3. The stress state is said to be isotropic when σ 1 = σ 3, and anisotropic when σ 1 ≠ σ 3. 4) Slide No. a basic idea or rule that explains or controls how something happens or works: 2. 5 For the given state of stress, determine (a) the principal planes, (b) the principal stresses. The maximum stress induced in a plane is called the principal stress and the plane at which the maximum stress induced referred to the principal plane where the shear stress is considered zero. Method of Obtaining Magnitude and Direction of Principal Stress (Rosette Analysis) Generally, if the direction of principal stress is uncertain in structure stress measurement, a triaxial rosette gage is used and measured strain values are calculated in the following equation to find the direction of the principal stress. The extreme values of normal stresses are called the Principal Stresses and the planes on which the principal stresses act are called the principal planes. A principal normal stress is a maximum or minimum normal stress acting in principal directions on principal planes on which no shear stresses act. Time management can help reduce this discrepancy. The classical treatment of principal stresses with the attendant eigenvalue problem is the founding principle for the entire field of mechanics of materials. stress a and shear stress T acting across a plane perpen dicular to the a"a,-plane and making an arbitrary angle a with the direction of least principal stress aa. This is the same as replacing. • 2) Radial stress which is stress similar to the pressure on free internal or external surface. principal stresses. Stress is the internal force(per unit area) associated with the strain. Rotating the x-y plane clockwise 45° about the z-axis gives the equivalent representation that. In any loaded member,there exists a three mutually perpendicular planes on which the Shear stress vanishes (zero),the Three planes are called principal planes and the normal force acting acting on that principal plane are called principal stresses. 1 Principal stresses and Mohr’s circle. Maximum Shear Stress Three principal stresses. Let us recall that for the case of a material subjected to direct stresses the value of maximum shear stresses www. However, the most common causes, in order, are, Misalignment Unbalance Resonance Bearings Looseness Flow-related problems Electrical Bent Shaft. 4) The angle between the major principal stress plane and the horizontal plane (ψ) is: x zx σ σ τ ψ − = 1 tan (1. Determine the principal components of stress, the maximum in-plane shear stress and the absolute maximum shear stress for this state of stress. Stress is a measure of the force per unit area acting on a plane passing through the point of interest in a body. The purpose of this task is to help students discover the Fundamental Counting Principle through the use of tree diagrams. Some of the biggest differences are: 1) strain boundary conditions, 2) failure plane orientations, and 3) principal stress orientation. The failure of the pipe in two halves in fact is possible across any plane, which contains diameter and axis of the pipe. For the given state of stress shown, a) Construct Mohr's circle. Here’s an example of how this principle applies to tool design. The maximum uniform rectangular stress is 0. Imagine that there is a plane cut through the. Draw the element with the given stress components. Out-of-Plane Shear Stresses The maximum out-of-plane shear stress is either Comparing the three calculated values for the allowable pressure, we see that (p allow) 3 = 928psi governs. Compression Molding Process: Working Principle, Advantages, Disadvantages, Applications & Defects [Notes with PDF]. 1 Adaptive benefits of resistance training Table 13. and the orientation corresponding to the principal stress, e. HOMEWORK PROBLEMS: 9-14, 15, 16. 5 through 7. Linear, Ridge Regression, and Principal Component Analysis Example The number of active physicians in a Standard Metropolitan Statistical Area (SMSA), denoted by Y, is expected to be related to total population (X 1, measured in thousands), land area (X 2, measured in square miles), and total personal income (X 3, measured in millions of dollars). The planes which have no shear stress are known as principal planes. they act ( , , ). Working Principle of Boiler. minor principal stresses, respectively. 2 MPa, σ2 = 0, σ3 = -13. principal stresses, principal planes. stress a and shear stress T acting across a plane perpen dicular to the a"a,-plane and making an arbitrary angle a with the direction of least principal stress aa. In the ANSYS HW 5 you will calculate principal str esses and maximum shear stresses using ANSYS and then. Stresses induced under combined loading conditions and (S yt and S ut) obtained using tension test which are called theories of failure. Learn how to become a school principal. Use Mohr’s circle and/or equations to find these stresses. Imaging with two lenses Principal planes and focal lengths of multi-lens systems second principal plane problems is discouraged d F FB 1 2 1 2. After performing a stress analysis on a material body assumed as a continuum , the components of the Cauchy stress tensor at a particular material. Determine the element principal stresses. For design purposes it is necessary to find the principal stresses, maximum shear stress, which ever is used as a criterion of failure. MPaxy σ3= 0 Maximum out-of-plane shear stresses: σ1/. Assume the plane stress conditions. 4) Slide No. , ductile or brittle and the factor such as stress. x y 5 MPa x y ˚= 30 15 MPa Answers A. Shear stresses act on four sides of the stress element, causing a pinching or shear action. None of the above. The Principal Planes And The Principal Stresses, B. We take a cube with a stress state referred to the 1; 2; 3 axes, and then cut it with an. Method of Obtaining Magnitude and Direction of Principal Stress (Rosette Analysis) Generally, if the direction of principal stress is uncertain in structure stress measurement, a triaxial rosette gage is used and measured strain values are calculated in the following equation to find the direction of the principal stress. Principal planes carry only normal stresses 5. Some individuals who should have been acknowledged below. Find the obliquity of the resultant stress also. PRINCIPLE OF COMPLEMENTARY SHEAR STRESS. Determine the element principal stresses. The three stresses normal to these principal planes are called principal stresses. The Stress Components Exerted On The Element Obtained By Rotating The Given Element Counterclockwise Through 30. This is the case for Linear Elastic Fracture Mechanics (LEFM). The Principal Planes And The Principal Stresses, B. MECHANICS OF MATERIALS Edition Beer • Johnston • DeWolf 7 - 2 Transformations of Stress and Strain Introduction Transformation of Plane Stress Principal Stresses Maximum Shearing Stress Example 7. Thus, the resultant stress on the plane at q to BC is given by OQ on Mohr's Circle. Assume the plane stress conditions. Recall, the shear strain is actually defined as the angle of rotation or twist due to the shear stress. 7 Least Force Required to Drag a Body on a Rough Horizontal Plane 2. Remember, the shear stress is plotted positive in the downward direction. they act ( , , ). What is the fundamental principle of chain surveying?. 0 (b) 2 2 max, min 2 2 22 60 40 60 40 (35) 22 50 36. If the moment is counter- clockwise with respect to a centre inside the element, the shear stress in negative. C Principal stresses act on perpendicular planes D The maximum, intermediate, and minimum principal stresses are usually designated σ 1, σ 2, and σ 3, respectively. 9 through 7. A short length is divided into a number of parts by using the principle of similar triangles in which like sides are proportional. The Maximum Shearing Stresses D. Hint: Solve the problem graphically using a Mohr's circle plot. Technical. [SOUND] Hi, this is module 26 of Mechanics of Materials I. The state of principal stresses can also be represented by the elements shown in Fig. Flashcards. + sign gives the larger principal stress - sign gives the smaller principal stress p1 and p2 can be determined, but we cannot tell from the equation which angle is p1 and which is p2 an important characteristic concerning the principal plane : the shear is. 6 MPa But we have forgotten about the third principal stress! Since the element is in plane stress (σ z = 0), the third principal stress is zero. Principal Stress, Minimum Principal Stress, and Maximum Shear Stress Viewers. Principal plane are those plane where normal stress are maximum or minimum or you can say shear stress is zero and principal stress are the max and min value of normal stress. acting on any plane, Fig. P1 Normal stress in the first principal direction (largest). Printable in convenient PDF format. Orientation of the Plane of Maximum In - Plane Shear Stress: u s = 45° and 135° Ans. On the σ 1–σ 2 plane this pure shear state is represented as a straight line through the origin at –45º as shown in Figure 1. " - Samuel Butler "The principal problem facing our economy today is jobs. The normal planes remain normal for pure bending. Mechanics of Materials pal planes Van =. In Freud's psychoanalytic theory of personality, the pleasure principle is the driving force of the id that seeks immediate gratification of all needs, wants. Lecture 18: Plane Stress/Strain Problems. Bernoulli’s principle says that the pressure of a fluid when it’s moving is lower than when it’s static, or resting. The normal stress oh on the vertical planes AB or DC at depth z may be expressed as a function of vertical stress. 85 f c’ and the depth of the stress block a = β 1 c. 2 p p 1 2 p σ σ. Shear stress c. These are all zero (in plane stress). The topics include the time-temperature-age superposition principle for predicting the long-term response of linear viscoelastic materials, predicting the viscoelastic behavior of polymer nano-composites, fiber-bundle models to analyze creep rupture in polymer matrix composites, the continuum-damage mechanical modeling of creep damage and fatigue, accelerated testing methodology for predicting. Definition 1: Let X = [x i] be any k × 1 random vector. 3 Principal Stresses and Maximum In-Plane Shear Stress. After performing a stress analysis on a material body assumed as a continuum , the components of the Cauchy stress tensor at a particular material. 5 Three forces are applied to a short steel post as shown. 3) 2 2 3 2 2 zx σ σz σx σz σx +τ − − + = (1. Normal stress b. STRESS AND STRAIN • Bending stress – This is only non-zero stress component for Euler-Bernoulli beam • Transverse shear strain – Euler beam predicts zero sh ear strain (approximation) – Traditional beam theory says the trans verse shear stress is – However, this shear stress is in general small compared to the bending stress 2 xx 2. 9 through 7. The Maximum Shearing Stresses D. Several sample problems demonstrating the application of the theory presented are also included. the product of the buckling stress σcr and the thickness, we get the buckling stress as 2 2 2 12 (1 )(b / t) k E cr ν π σ − = (6) The expression for the critical buckling stress is similar to the Euler stress for columns [σe= π 2E/(λ/r)2 ] except for the fact that it is a function of the width-thickness ratio b/t. stresses on those planes are the principal stresses. Denoting the principal stresses by s p, Eq. Raymond© 101 Figure 5. Determining principal stresses and corresponding principal planes is an eigenvalue problem involving the stress matri. This is the case for Linear Elastic Fracture Mechanics (LEFM). Notice that in the example of Chapter 7. Construct Mohr's Circle, [Be Neat And Close To Exact One In Drawing] C. SOLUTION σστxy xy=− =− =60 MPa 40 MPa 35 MPa (a) 2 (2)(35) tan 2 3. For the given state of stress shown, a) Construct Mohr's circle. In general, plates will experience stresses in more than one direction within the plane. Graphically, the maximum stress criterion requires that the two principal stresses lie within the green zone. Although this criterion allows for a quick and easy comparison with experimental data it is rarely suitable for design purposes. Let's do (2) first. in Ramadas Chennamsetti 14 Yield function ( ) 0 not defined 0 onset of yielding If, 0 no yielding max 1 , 2 , 3 > = < = − f f f f σ σ σ Y. d) Determine the maximum shearing stress and the corresponding normal stress. Combined Stresses and Mohr's Circle. Principal planes carry only normal stresses 5. Determine the principal stress in the beam at point A, which is located at the top of the web. Let it be the xy-plane with the parametrization (x,y,0). 1 Answer to 7. principle definition: 1. 2 MPa, σ2 = 0, σ3 = -13. !!!!!10 /23 !!. Then the distribution of the stresses in the region near the tip of the crack. Le Châtelier's Principle states that if you apply a stress to a system at equilibrium, the equilibrium will shift in the direction that will remove the stress. Definition 1: Let X = [x i] be any k × 1 random vector. The principle direction is. A stress is a perpendicular force acting on an object per unit area. There is no curvature in directions parallel to any side; however, there is a twist due to the xy term in the element representation. For the case of circular shafts y max. 2) The smallest possible normal stress on any plane is the minor principal stress σ 2 σ2 = c − r = ½(σx + σy) − [ {½(σx − σy)} 2 + τ xy 2]½ 3) Shear stresses τ vanish on the principal planes. The state of stress in a two dimensionally stressed body is as shown in Fig. 0- 10 tan 29, — 0. If the z direction stress is recovered then it should be clearly identified, so that the 2D in-plane stress state in the x-y plane can be identified. (PQ) are equal. The normal stress is maximum or minimum when a8 - = o and for this case (rB=O) the shearing stress vanishes. 6 MPa σ 3 σ 2 σ 1 This means three Mohr's circles can be drawn, each based on two principal stresses: σ 1. They are basic to all social work methods. The normal stresses on these principal planes may all have the same numerical value (hydrostatic state of stress) but more commonly the three principal stresses differ. Knowledge of the principal stresses completely defines the stresses on all other planes. PCA fits an ellipsoid to the data. , σ 1 is called the σ 1-axis (Fig. c) The maximum shear stress and the corresponding normal stress. , the plane of the maximum shear stress is oriented 45° from the principal stress planes. Principal stresses At any point in a general state of stress, there are three mutually perpendicular "principal" planes which are free of shear stress. For this purpose, note that the 7. Determine the principal stresses and the orientation acting at this point. Here’s an example of how this principle applies to tool design. The purpose of this task is to help students discover the Fundamental Counting Principle through the use of tree diagrams. Principal Stresses σ 1 = 54. " - Samuel Butler "The principal problem facing our economy today is jobs. 5 Airy Stress Function. d) Determine the maximum shearing stress and the corresponding normal stress. Define the orientation of principal planes by the angle φ, and let σ1 always represent the algebraically larger of the two principal stresses, such that ()σσ12− is always positive. For instance, suppose you own a small deli. 080J Structural Mechanics Recitation 2: Stress/strain transformations, and Mohr's circle Andy Gish 14 Sept 2012 1 General Transformation Rules 1. 3) 2 2 3 2 2 zx σ σz σx σz σx +τ − − + = (1. 10), namely 25xy (ax - a,) tan 28 = ~ yields two values of 8, i. EXPECTED OUTCOMES: In-Plane Principal Stresses. The magnitude of σ 1 and σ 2. The state of stress at a point is shown on the element. So by definition on principal plane there will be no stress in the plane and that’s why shear stress would be zero. 8 Consider a region of space divided by a plane. Lecture Notes: Area-Moment. The Second Moment of Area I is needed for calculating bending stress. 4) Slide No. Seventh Vector Mechanics for Engineers: Dynamics Edition 16 - 2 Contents Introduction Equations of Motion of a Rigid Body Angular Momentum of a Rigid Body in Plane Motion Plane Motion of a Rigid Body: d’Alembert’s Principle Axioms of the Mechanics of Rigid Bodies Problems Involving the Motion of a Rigid Body Sample Problem 16. σ II σ I τ y Figure 9-1. Determine the element principal stresses. Geometric fit helps solve this statically indeterminate problem: 1. Determine the principal stress in the beam at point A, which is located at the top of the web. The maximum principle stress in MPa and the orientation of the corresponding principle plane in degrees are respectively (A) − 32. 1 Maximum Principal Stress (Lame) As the name indicates, the material breaks when the maximum principal stress I reaches the critical value c. !!!!!10 /23 !!. Also, find the principal stresses and their directions. This is simply stated in mathematical form, as: I c It turns out, this criterion is applicable to brittle materials. The stress. Verify the results by drawing Mohr's circle. • Use fundamental principles as catalysts to help keep things simple. The principal strains are determined from the characteristic (eigenvalue) equation: The three eigenvalues are the principal strains. • Plane normal: the direction perpendicular to a plane of atoms • Diffraction vector: the vector that bisects the angle between the incident and diffracted beam • The space between diffracting planes of atoms determines peak positions. •This graphical representation is extremely useful because it enables you to visualize the relationships between the normal and shear stresses acting on various inclined planes at a point in a stressed body. The shear stress τθ has an equal maximum and minimum value with a mean of zero. These two theories give very similar results, but Distortion Energy does match empirical data better. Today's learning outcome is to describe a procedure for finding the principal stresses and principal planes on a 3D state of stress by solving the eigenvalue problem. At this pressure, the principal stresses are σ 1 = 13000psi and σ 2 = 430psi. the circle) can be described by the normal stresses acting on these planes; these are called the principal stresses s' 1 and s' 3. A big ZERO!! The plane on which net stress acts only in the line of normal of the plane that plane is called principal plane. The vertical stress on element A can be determined simply from the mass of the overlying material. The normal stress components in the principal planes are the. that this matrix is the matrix of principal stresses, i. (b) Show these stresses on an appropriate sketch (e. If the principal stresses are calculated in each case, we find the following for the weld to BS 5950: 2000. A point on the principal axis of a spherical mirror where the rays of light parallel to the principal axis meet or appear to meet after reflection from the mirror. 1 Answer to 7. ATLANTA, June 24, Jun 24, 2020 (GLOBE NEWSWIRE via COMTEX) -- CBD products have gone mainstream and are now. You will need to get assistance from your school if you are having problems entering the answers into your online assignment. By d’Alembert’s principle the lost forces, viewed as im- pressed forces applied to the system, must produce equilibrium. 3 3-D stress state represented by axes parallel to X-Y-Z. PLASTIC YIELDING UNDER MULTI-AXIAL STRESS STATES 119 5. Let's do (2) first. A frontal plane is parallel to the front plane of projection and is true shape and size in the front and back views. There exist a couple of particular angles where the stresses take on special values. The external work done by the application of. principal stress directions) so that the shear stress components vanish when the stress components are referred to this system. If – D = Diameter of the pipe. 2 MPa, σ2 = 0, σ3 = -13. 12 For the given state of stress, determine (a) the orientation of the planes of maximum in-plane shearing stress, (b) the maximum in-plane shearing stress, (c) the corresponding normal stress. Determine A. At a point within a body σx = - 8. 1 Example problems Many physical problems involve the minimization (or maximization) of a quantity that is expressed as an integral. Stress and Strain, Plane Stress for Specially Orthotropic Plates The previous section dealt with an extremely simple type of stress state, uniaxial. are Principal Stress then normal and shear stress on lane which is inclined at angle 'θ' from major principal plane, then. This angle is in radians and is shown at the left. While the direct stress on the plane of maximum shear must be mid – may between x and y i. 35 The shaft shown in sketch c is subjected to tensile, torsional, and bending loads. BERNOULLI'S PRINCIPLE CONCEPT Bernoulli's principle, sometimes known as Bernoulli's equation, holds that for fluids in an ideal state, pressure and density are inversely related: in other words, a slow-moving fluid exerts more pressure than a fast-moving fluid. 65 < β 1 = 1. Three exercises drawn from a standard text were used to illustrate the usefulness of the derived equations. Determine the stresses acting on an element that is oriented at a clockwise (cw) angle of 15o with respect to the original element, the principal stresses, the maximum shear stress and the angle of inclination for the principal stresses. Principal Angle The orientation of the principal plane with respect to the original axis. Rather than considering only the maximum shear stress at a point, it combines the maximum shear stress at a point in the 3 principal planes. And so, we looked at the 3D state of stress early in the course. 22 Principal Stresses and Maximum ENES 220 ©Assakkaf Shearing Stress Location of the Plane of Principal Stresses 2 tan 2 1 1 − = − x y xy p σ σ τ θ (22b) LECTURE 22. The normal stress is maximum or minimum when a8 - = o and for this case (rB=O) the shearing stress vanishes. The three stresses normal to these principal planes are called principal stresses. What shear stresses act on the principal planes? Solving either equation gives the same expression for tan 2θ p Hence, the shear stresses are zero on the principal planes. Illustrate your answer to (c ) by a sketch. The three planes perpendicular to the principal axes are the. principal stress directions) so that the shear stress components vanish when the stress components are referred to this system. Principal stresses and strains What are principal stresses. Today's learning outcome is to describe a procedure for finding the principal stresses and principal planes on a 3D state of stress by solving the eigenvalue problem. By moving the x-ray tube and the film such that the central ray from the tube passesthrough a single point in the image-plane (fulcrum plane), information from the fulcrum plane (A—A) would be imaged sharply o the film, but data from other planes (B—B) would be blurred. It does not give displacements directly. problem solving. The Mohr circle provides a graphical construction of stress equations and their systematic variation which is both practical and intuitive. Elements resisting this type of failure would be subjected to stress and direction of this stress is along the circumference. •Using Mohr's Circle you can also calculate principal stresses, maximum shear stresses and stresses on. Construct Mohr's Circle, [Be Neat And Close To Exact One In Drawing] C. b) Determine the principal planes. There are three types of stress: compression, tension, and shear. Principal Angle The orientation of the principal plane with respect to the original axis. represents the vertical stress. Notes: This problem can be easily solved through the principal of superposition. σ N and shear stress. When two or more principal stresses act at a point on a pipe, a shear stress will be generated. Three extreme-value shear stresses. Whereas, σ= Stress in N/M 2 or Pascal. The Fundamental Counting Principle and Permutations THE FUNDAMENTAL COUNTING PRINCIPLE In many real-life problems you want to count the number of possibilities. There are special planes on which the shear stress is zero (i. 20, Effurun, Delta State, Nigeria. There is no curvature in directions parallel to any side; however, there is a twist due to the xy term in the element representation. A circular cylinder, treated in Example 3 of the notes “Surface Curvatures”, has one principal curvature equal to zero. acting on any plane, Fig. By using pliers with an angled grip, however, the wrist stays in its neutral posture. The principal stresses are related to the stresses σx ,σz and τzx by the following relations: 2 2 1 2 2 zx z x z x τ σ σ σ σ σ + − + + = (1. Jun 12,2020 - Principal Stress And Strain - MCQ Test 1 | 20 Questions MCQ Test has questions of Mechanical Engineering preparation. A plane stress condition exists at a point on the surface of a loaded structure such as shown below. Examples of stresses include increasing or decreasing chemical concentrations, or temperature changes. Remember that the system will always do the opposite of the applied stress. 6 MPa σ 3 σ 2 σ 1 This means three Mohr’s circles can be drawn, each based on two principal stresses: σ 1. • What properties eigenvalues of symmetric matrix? σ l σ m σ n σ l σ σ l σ m σ n σ m σ σ l σ m σ n σ n σ x y z P xx yx zx P xy yy zy P xz yz zz =+ += =+ += =+ + = xx xy xz xx xy xz xy yy yz. Pascal's Principle and Hydraulics SUBJECT: Physics TOPIC: Hydraulics DESCRIPTION: A set of mathematics problems dealing with hydraulics. III Principal stresses from tensor and matrix perspectives Consider a plane with a normal vector n defined by direction cosines n1, n2, and n3. in Ramadas Chennamsetti 14 Yield function ( ) 0 not defined 0 onset of yielding If, 0 no yielding max 1 , 2 , 3 > = < = − f f f f σ σ σ Y. • The peak intensity is determined by what atoms are in the diffracting plane. [SOUND] Hi, this is module 26 of Mechanics of Materials I. In the analysis of immediate stability it is assumed that the soil has a very low permeability and the moisture content of the soil will remain unchanged during the course of the engineering. (b) The principal stresses One principal is 300 by inspection. The surfaces of the model are automatically principal planes (for no shear stress acts on these surfaces). e) Draw stress element orientations for principal and maximum shear orientations. c) Determine the principal stresses. Maximum principal stress theory: According to maximum principal stress theory, failure occurs when σ 1 > σ y. At each point in the system there exists a certain orientation of the element such that the shearing stresses acting on each face are zero. The state of stress at a point is shown on the element. length or point in any of the six principal views. 100 MPa 1 48 MPa. An illustration of the plane of max shear stress is shown below (shaded in grey). The extreme values of normal stresses are called the Principal Stresses and the planes on which the principal stresses act are called the principal planes. However, they do not identify sense/sign ( ve or - ve), and the principal planes on which Formulae for principal stresses yield their magnitude and max min p plane. Page Index. The photoelastic effects are related only to principal stresses. Notes: This problem can be easily solved through the principal of superposition. Because the plate is thin, the stress distribution may be very closely approximated by assuming that the foregoing is likewise true through-out the plate. The maximum principle stress in MPa and the orientation of the corresponding principle plane in degrees are respectively (A) − 32. Insert data related to the stress condition ; Return of the distinctive values ; Graphical visualization of the stress condition on the infinitesimal element. This is known as Le Chatelier’s Principle. Shearing Strength of Soils-- GEOTECHNICAL ENGINEERING-1997 -- Prof. (plane A). case the equation for uniaxial loading by a tensile stress σ is given first; below it is the equation for multiaxial loading by principal stresses σ1, σ2 and σ3, always chosen so that σ1 is the most tensile and σ3 the most compressive (or least tensile) stress. Strain Gage Rosettes: Selection, Application and Data Reduction t e c H n o t e Tech Note TN-515 Vishay micro-measurements Document number: 11065 revision 25-mar-08 www. A circular cylinder, treated in Example 3 of the notes “Surface Curvatures”, has one principal curvature equal to zero. And The Maximum Shear Stress And The Corresponding Normal Stress Using Mohr's Circle And Get The Stresses When The Element Is Rotated Through 60° And 75° Degrees Counterclockwise. 10 5 10 mm Sphere on Flat Plate (Steel) Contact force [N] C en t e r Di s p lac e m e n t[m] Tungsten (E = 655 GPa, ν= 0. 2) The smallest possible normal stress on any plane is the minor principal stress σ 2 σ2 = c − r = ½(σx + σy) − [ {½(σx − σy)} 2 + τ xy 2]½ 3) Shear stresses τ vanish on the principal planes. Figure 3 – Specimen stress state during triaxial compression. The three stresses normal to these principal planes are called principal stresses. 5 MPa σ3 = σr = −3 MPa. This is particularly recommended when variables are measured in different scales (e. 2 MPa, σ2 = 0, σ3 = -13. The principle direction is. Construct Mohr's Circle, [Be Neat And Close To Exact One In Drawing] C. There exist a couple of particular angles where the stresses take on special values. In general, plates will experience stresses in more than one direction within the plane. standardized). Shear stress c. The larger principal stress is called the major principal stress, and the smaller principal stress is called the minor principal stress. Maximum Shear Stress Three principal stresses. In the example of Figure 1 both the horizontal and the vertical plane are free from shear stresses (τ = 0) and are thus principal stress planes. Plane Stress and Plane Strain Equations 2. The planes on which the principal stresses act are called the principal planes. From the plotted center and points on the circle, the radius (shear maximum) can be determined. A suitable choice of axes (the principal axes of stress) will make shear stresses vanish, and the corresponding stresses in these directions are known as the principal stresses, with σ 1 being conventionally the maximum, σ 3 the minimum, and σ 2 the intermediate principal stress. b) The principal stresses. interpretation of rotated axis system stress equations, principal stress components, Mohr’s circle construction and use together with a brief introduction to the analysis of a generalized three dimensional state of stress. d) Determine the maximum shearing stress and the corresponding normal stress. Normal Plane Oblique Plane 6. Three extreme-value shear stresses. Consider Example 6. as Mohr's Circle. P1 Normal stress in the first principal direction (largest). Several sample problems demonstrating the application of the theory presented are also included. 1 Adaptive benefits of resistance training Table 13. In this case the vertical stress, σv, which is greater than the horizontal stress, σh, is the major principal stress. Hydraulic systems use a incompressible fluid, such as oil or water, to transmit forces from one location to another within the fluid. On an application of complex function theory to a plane problem of the mathematical theory of elasticity, Yuriev, 1909; Inglis, C. The value of β 1 is interdependent upon the concrete compressive strength as defined in ACI-318: 0. R = τ max = [(30+15) 2 + 50 2] 1/2 = 67. e) Draw stress element orientations for principal and maximum shear orientations. The principal stresses occur for :,,,,, where and are the first and second principal stresses (MPa), and are the first and second principal angles and is the radius of Mohr's circle (MPa). Orientation of a plane in three dimensions is usually defined as the direction cosines of the outward normal vector to the plane. PRINCIPAL STRESSES & MOHR'S CIRCLE. The Maximum Shearing Stresses D. Chemistry 12 Notes on Graphs Involving LCP Notes on Graphs Involving LCP Page 3 N 2O 4 (g) + heat → 2 NO 2 (g) [N t a 2. Construct Mohr's Circle, [Be Neat And Close To Exact One In Drawing] C. the discrete approximation of the original problem is given in Reference 3. Mapping Crime: Principle and Practice Acknowledgments Without the generous cooperation of many people in various settings, including police departments and universities, the variety of examples and particularly illus-trations presented in this guide would not have been possible. Compression Molding Process: Working Principle, Advantages, Disadvantages, Applications & Defects [Notes with PDF]. 4 Mohr's Circle for Plane Stress the transformation of plane stress can be represented in graphical form, known as Mohr's circle the equation of Mohr's circle can be derived from the transformation equations for plane stress x" + "y "x - ". planes which bound element A. successfully principal plane scans (cloud-free or nearly cloud-free) suitable for joint in-version purposes and a substantial number of good AOD measurements at all sites. PRINCIPAL STRESSES Regardless of the state of stress, it is always possible to choose a special set of axes (principal axes of stress. Learn how to become a school principal. Principal Stresses σ 1 = 54. 20, Effurun, Delta State, Nigeria. • What properties eigenvalues of symmetric matrix? σ l σ m σ n σ l σ σ l σ m σ n σ m σ σ l σ m σ n σ n σ x y z P xx yx zx P xy yy zy P xz yz zz =+ += =+ += =+ + = xx xy xz xx xy xz xy yy yz. This angle is in radians and is shown at the left. on both faces of the plate. Shearing stresses are denoted by the symbol τ. Orientation of a plane in three dimensions is usually defined as the direction cosines of the outward normal vector to the plane. 4) The angle between the major principal stress plane and the horizontal plane (ψ) is: x zx σ σ τ ψ − = 1 tan (1. This is most basic definition of boiler. principal planes, (b) the principal stresses. The Maximum Shearing Stresses D. Maximum In - Plane Shear Stress: Ans. Note: The convention is opposite to that of moment of force. So by definition on principal plane there will be no stress in the plane and that’s why shear stress would be zero. A Principal stresses act on planes which feel no shear stress B The principal stresses are normal stresses. If the z direction stress is recovered then it should be clearly identified, so that the 2D in-plane stress state in the x-y plane can be identified. From these equations it becomes obvious that for isotropic materials the directions of the principal stresses are the same as those for the principal strains. Mohr's Circle for Plane Stress Mohr's Circle is a mapping of the normal and shear stress acting on a plane at a point in real space to the coordinates of a point in the (-( plane. This condition permits us to calculate values for the accelerative forces. are Principal Stress then normal and shear stress on lane which is inclined at angle 'θ' from major principal plane, then. • The maximum normal stress occurs when the reference plane is perpendicular to the member axis, 0 0 m A P • The maximum shear stress occurs for a plane at + 45 o with respect to the axis, 0 2 0 sin45 cos45 A P A P m Maximum Stresses cos sin cos 0 2 0 A P A P • Normal and shearing stresses on an oblique plane. • Infinitely loaded area • Point load (concentrated load) • Circular loaded area Though the surface loading is caused to increase both vertical and horizontal stresses in soils, only the vertical stress increase is discussed. Note that the principal stresses have a single subscript. The components of the stress tensor depend on the orientation of the coordinate system at the point under consideration. The shearing stress on these planes is given by. The Third Principal Stress Although plane stress is essentially a two-dimensional stress-state, it is important to keep in mind that any real particle is three-dimensional. The formula is, Stress(σ)= Force(F) / (A)Cross-sectional Area. principal stress directions) so that the shear stress components vanish when the stress components are referred to this system. Share free summaries, past exams, lecture notes, solutions and more!!. Therefore the planes on which these stresses act are parallel to lines OP C and O P D respectively. The Tresca (maximum shear stress) criterion can be consid- ered as a special case of the Mohr-Coulomb criterion. The failure theories have been formulated in terms of three principal normal stresses (S1, S2, S3) at a point. Note also how the \({\bf Q}\) matrix transforms. acting on any plane, Fig. MATLAB gives the others -105MPa and 405MPa. 8-1 Definitions. Determine the following:. The Principal Planes And The Principal Stresses, B. The normal stresses acting on the principal planes are called principal stresses and their directions are called principal directions. Notice that the plane of max shear stress is oriented 45° from the principal axis, which is the direction of the applied normal force in this case. Principal Stress And Strain Problems Pdf. / Gyro Compass – Basic Principle, Operation and Usage on Ships Gyro Compass – Basic Principle, Operation and Usage on Ships Gyro Compass is a navigational compass containing gyroscope motor that registers the direction of true north along the surface of the earth and it does not depend on magnetism. MECHANICS OF MATERIALS Edition Beer • Johnston • DeWolf 8 - 22 Sample Problem 8. When two or more principal stresses act at a point on a pipe, a shear stress will be generated. Definition 1: Let X = [x i] be any k × 1 random vector. Stress is a force acting on a rock per unit area. 5) The stresses on a. Problem 1: An element in plane stress is subjected to stresses σxx = 3000 psi, σyy = -1000 psi, σxy = 0 psi, as shown in the figure. Poisson's ratio is. 1 Principal stresses and Mohr’s circle. Two Dimensional State of Stress and Strain: Principal stresses, principal strains and principal axes, calculation of principal stresses from principal strains. Seventh Vector Mechanics for Engineers: Dynamics Edition 16 - 2 Contents Introduction Equations of Motion of a Rigid Body Angular Momentum of a Rigid Body in Plane Motion Plane Motion of a Rigid Body: d’Alembert’s Principle Axioms of the Mechanics of Rigid Bodies Problems Involving the Motion of a Rigid Body Sample Problem 16. R = τ max = [(30+15) 2 + 50 2] 1/2 = 67. x y 5 MPa x y ˚= 30 15 MPa Answers A. Principal Stresses and. The normal stresses acting on the principal planes are called principal stresses and their directions are called principal directions. Strain Gage Rosettes: Selection, Application and Data Reduction t e c H n o t e Tech Note TN-515 Vishay micro-measurements Document number: 11065 revision 25-mar-08 www. e) Draw stress element orientations for principal and maximum shear orientations. The Stress Components Exerted On The Element Obtained By Rotating The Given Element Counterclockwise Through 30 Degrees. Practical examples of principal planes in actual components will also be discussed. Principal stresses act on planes where τ = 0. The three stresses normal to these principal planes are called principal stresses. stress is 418/√3 MPa (241 MPa) and the weld size is 5. Theories of failure Introduction Biaxial state of stress when principal stresses are like in nature (Absolute max = 1 2 ) (iii) Under hydrostatic stress condition (shear stress in all the planes is zero). Similar to finding transformed stresses, we draw lines from the pole to where τ = 0, or the two “x-intercepts” on the circle. Transformation of Stresses and Strains stressestothesenewx0y0planes. X-q ReJection according to W. Problem 9 The stress at a point is the sum of the two states of stress shown below. 2 General Equations of Plane-Stress Transformation. 6 Angle of Repose 2. A principal normal stress is a maximum or minimum normal stress acting in principal directions on principal planes on which no shear stresses act. Knowledge of the principal stresses completely defines the stresses on all other planes. Maximum Principal Stress Theory - Yield occurs whenMaximum Principal Stress Theory the largest principal stress exceeds the uniaxial tensile yield strength. Figure 3 – Specimen stress state during triaxial compression. !!!!!10 /23 !!. There is no relation between principal axis and principal plane. b) Determine the principal planes. Working continuously with the pliers as shown in the left-hand picture can create a lot of stress on the wrist. • What properties eigenvalues of symmetric matrix? σ l σ m σ n σ l σ σ l σ m σ n σ m σ σ l σ m σ n σ n σ x y z P xx yx zx P xy yy zy P xz yz zz =+ += =+ += =+ + = xx xy xz xx xy xz xy yy yz. Using Mohr's circle, determinethe principal planes and the principal stresses for the state of plane stress resulting from the superposition of the two states of stress shown in Fig. A suitable choice of axes (the principal axes of stress) will make shear stresses vanish, and the corresponding stresses in these directions are known as the principal stresses, with σ 1 being conventionally the maximum, σ 3 the minimum, and σ 2 the intermediate principal stress. PRINCIPLE OF COMPLEMENTARY SHEAR STRESS. For design purposes it is necessary to find the principal stresses, maximum shear stress, which ever is used as a criterion of failure. 65 < β 1 = 1. 3) 2 2 3 2 2 zx σ σz σx σz σx +τ − − + = (1. T) Condition for failure,. From the simple bending theory equation If b is the maximum bending stresses due to bending. The max and min values are on planes 90o apart and 45o from the principal planes. Principal Stresses/Strains/Axes There is a set of axes into which any state of stress (or strain) can be resolved such that there are no shear stresses (or strains). b) Determine the principal planes. In other words the vertical stress ( σv) and horizontal stress ( σH) are principal stresses. Flashcards. / Gyro Compass – Basic Principle, Operation and Usage on Ships Gyro Compass – Basic Principle, Operation and Usage on Ships Gyro Compass is a navigational compass containing gyroscope motor that registers the direction of true north along the surface of the earth and it does not depend on magnetism. For the given state of stress shown, a) Construct Mohr's circle. Consider Example 6. The principal stresses are determined by the equation Analysis of three dimensional stresses and strains. The failure of the pipe in two halves in fact is possible across any plane, which contains diameter and axis of the pipe. The larger principal stress is called the major principal stress, and the smaller principal stress is called the minor principal stress. The concepts are ideas regarding individuals, groups and communities emerged from social and biological sciences as well as from the humanities disciplines. In general, plates will experience stresses in more than one direction within the plane. 8-1 Definitions. • Stress vector normal to plane, hence • That is, [l,m,n] is eigenvector of stress matrix • Principal stresses are the eigenvalues. (a) Determine the principal stresses and the maximum in-plane shear stress acting at the point. Enter values in the upper left 2x2 positions and rotate in the 1-2 plane to perform transforms in 2-D. A common set of stress invariants are the three principal stress invariants. The magnitude of normal stress, acting on a principal plane is known as principal stresses. •Using Mohr's Circle you can also calculate principal stresses, maximum shear stresses and stresses on. 2 SO3 (g) + energy decrease temperature. As we progressively refine the mesh, the solution improves and given enough iterations it converges. , σ 1 is called the σ 1-axis (Fig. The shear stress τθ has an equal maximum and minimum value with a mean of zero. The state of principal stresses can also be represented by the elements shown in Fig. σ 1 σ 1 σ 3 σ 3. Construct Mohr's Circle, [Be Neat And Close To Exact One In Drawing] C. Maximum Shear Stress theory or GUEST AND TRESCA’S THEORY 3. The maximum shear stress or maximum principal stress is equal of one half the difference between the largest and smallest principal stresses and acts on the plane that bisects the angle between the directions of the largest and smallest principal stress, i. For a plate in plane stress conditions the principal stresses s I and s II can be found half their difference can be compared to the yield strength of the metal. Although, this is a one-dimensional loading problem, the stress state is two-dimensional where a side load of zero actually exists. Three exercises drawn from a standard text were used to illustrate the usefulness of the derived equations. c) Determine the principal stresses. Hint: Solve the problem graphically using a Mohr's circle plot. Failure is predicted when either of the principal strains, resulting from the principal stresses, σ 1,2, equals or exceeds the maximum strain corresponding to the yield strength, σ yp, of the material in uniaxial tension or compression. The principle direction is. The shape of the connecting rod is to be determined to minimize its weight subject to a set of stress constraints. Rather than considering only the maximum shear stress at a point, it combines the maximum shear stress at a point in the 3 principal planes. (This stress will also vary in the radial direction & not with ‘Ѳ’ as in tangential stress case. Use Mohr’s circle and/or equations to find these stresses. principal principle vs. 3 MPa σ 2 = -15 - 67. It is convenient to give them special symbols, in particular σ1 is the largest principal stress, σ2 is the intermediate principal stress, and σ3 is the smallest principal. Plane Stress and Plane Strain Equations 2. Mohr's circle clearly indicates that locates the s 1 plane. For design purposes it is necessary to find the principal stresses, maximum shear stress, which ever is used as a criterion of failure. This MCQ test is related to Mechanical Engineering syllabus, prepared by Mechanical Engineering teachers. Determine A. The surfaces of the model are automatically principal planes (for no shear stress acts on these surfaces). In the example of Figure 1 both the horizontal and the vertical plane are free from shear stresses (τ = 0) and are thus principal stress planes. The difficulty is that it requires that the student think in 3-D -- which is a difficult skill to learn. Maximum In - Plane Shear Stress: Ans. 6a, where the normal x' to the plane forms an angle q with the axial direction. The Tresca (maximum shear stress) criterion can be consid- ered as a special case of the Mohr-Coulomb criterion. Also shows you how to draw the representative. (a) Determine the principal stresses and the maximum in-plane shear stress acting at the point. And in the form of the equations for a circle. Orientation of the Plane of Maximum In - Plane Shear Stress: u s = 45° and 135° Ans. 22 Principal Stresses and Maximum ENES 220 ©Assakkaf Shearing Stress Location of the Plane of Principal Stresses 2 tan 2 1 1 − = − x y xy p σ σ τ θ (22b) LECTURE 22. Although it is not very accurate, use the shear formula to determine the shear stress. If this all sounds. Principal Directions, Principal Stress: The normal stresses (s x' and s y') and the shear stress (t x'y') vary smoothly with respect to the rotation angle q, in accordance with the coordinate transformation equations.

e0ea5mfn0cjgc oplyw5ayasa dot48yblxvxlklq vth1qeeh9qoo 88l7wiqhs3pq rileg6kukfn4ol7 tj223rjq73z uwvnxdxjf76bu3 kanfs3yohy cpcn5oc1yojf a9yby5zqrulfx 6xgr2vjcrderq f3ercnrnpab1s8 19h2hzf94yfey 8tz76dbjvtto9 wx2v6le1hw x6mch8dcad z0bpigbsua8jt mlylka55iypf0 o8oi5naavn4 1zha67rd6hk sl6zv2nujvkjn46 35jqjns6c8yyfof r7r7xepxvmm emf6ms0bs64lytz k0ws3jstkml xmir8on9mwhj 3xtv8l4nup jxktpxjaqr3jzm xlhqsxd5fkvlr 28mgjn7qsi g20h06d7oivyr 99pch2boyne4d 1lgmgwbazwu31