Stress Definition and 1000 Threads

  1. S

    General Relativity: Curvature and Stress Energy Tensor

    Hello all, I have a quick question regarding the relation of the space-time metric and the curvature. I have determined the space-time metric, g_(alpha beta), but I am unsure as how to go from the line element ds^2 = [ 1 + (dz/dr)^2] dr^2 + r^2 dtheta^2 and the space-time metric g to the...
  2. P

    Shear stress in thin wall beams

    Homework Statement http://postimg.org/image/9va37id55/ The question is to find the shear stress at the points A, B and C. The solution uses the sectioning planes aa, bb and cc to do so. For example, at C, how should I know whether to use a horizontal or vertical sectioning plane. Also, how...
  3. T

    Bending Stress in Top of T-Beam

    Homework Statement T-Beam is Steel with E=200GPa Find Max bending stress MC/I (right side where no glue)[/B] 80KG Load at Point "A" shown on the Top view Blue stuff is glue, the right side has no Glue, so its just empty space 2. The attempt at a solution I = BH^3/12 , where B = 0.04m H =...
  4. T

    How to find the torque, power and shear stress in this case

    Here is the sketch of the tv mount. http://1drv.ms/1G4yW6W The known values to me are the diameter of the rod (6mm), the length of the rod (600mm), the mass of the TV= 8.7kg and that the tv is supposed to move 600mm in 5 secs. Is there any information that I am missing in order to calculate the...
  5. G

    Tensile Stress and shear stress

    Suppose, a mild steel bar is being pulled from both ends.The stress acting on it will be tensile in nature.There is no compressive stress on material in this situation.When the pull exceeds material's yield strength,plastic deformation and strain hardening will occur.If pulling force is...
  6. W

    Poisson's ratio for a rigid rod

    I have a conceptual misunderstanding it seems. Poisson's ratio is the ratio of elastic strain deformation of the transverse and longitudinal components. That being said, if I were to induce thermal stress (heating up) to a rod by keeping its ends (longitudinal component) rigid, would there be a...
  7. M

    How Do You Calculate Shear Stress in Beams with Pin Reactions?

    1. Determine average shear stress. Question attached2. Shear Stress = F/A , Sum of Forces and Moments = 0, Trig3. Attempt attached. Having a hard time determining reaction at pins. I worked out that the opposite side is 4.5m. I assume the next step is to determine reaction then apply Shear...
  8. R

    Stress analysis for a Bent Pipe

    I am a student currently working on a group project regarding the design of a gooseneck for a sub-sea pipeline. For those not familiar, a gooseneck is essentially a 45 degree bent pipe, to be used as a connection between a manifold and a longer pipeline (a flexible riser). part of this design is...
  9. 1350-F

    Differential Yield Stress and Von Mises Criterion

    If I have the differential yield stress σd=(σ1-σ3) for a material, what can I derive from that for use with the von mises criterion? Do I have k=0.5×(σ1-σ3) or σy in axial tension, where σ3 = 0? Essentially is my axial yield stress = σd or √3 × σd /2? (in plane stress)
  10. R

    Stress at crack tip of a 2D cantilever beam under sinusoidal excitation

    I need some information urgently. I am working on crack of a 2-D cantilever beam. One side of the beam is fixed. I am applying a sinusoidal time varying load on other end in Y-direction.Beam length and width are 100cm and 10cm respectively. crack is 05 cm in y-direction. I have attached data and...
  11. kelvin490

    Same E for true stress true strain?

    Before yield we know that stress/strain= E. Can we obtain the same E if we substitute true stress and true strain in the equation? Why
  12. D

    Four divergence of stress energy tensor

    Homework Statement Hi, I'm trying to show the four divergence of the stress energy tensor of the sourceless klein gordon equation is zero. I got to the part in the solution where I am left with the equations of motion which is identically zero and 3 other terms. I managed to find a solution...
  13. O

    Material A & B Stress: What's the Difference?

    Homework Statement Two identical sized specimens of materials A and B are made from materials which produce stress v strain graphs as shown below. The specimens are arranged in a press, the press moves uniformly, which of the specimens would be under the greatest stress? Homework Equations...
  14. CivEngMo93

    Structural Stability & buckling stress

    Q: A structure is made from identical, axially compressible robs connected to a rigid foundation. The rods cannot buckle. In the unloaded configuration the angle between the rods and the horizontal is (alpha); then angle becomes (1-Beta)*alpha when p =/= 0. Find the relationship P(Beta)...
  15. T

    Shear stress calculation question

    Homework Statement I've been working on this question for a while but can't get anywhere. I was able to calculate Force BD and Force CE Now I am not sure how they calculated the area of section BD the math isn't making much sense to me Homework Equations σ = P / A A= π r2 The Attempt at a...
  16. T

    Calculating Force for Punching a Hole in a Plate

    Homework Statement What force is required to punch a 20-mm-diameter hole in a plate that is 25 mm thick? The shear strength is 350 MN/m2. Homework Equations σ = V / A The Attempt at a Solution The first thing I did was rearrange the formula to isolate for V. I got the area which (A=πr2) gave...
  17. S

    Physical interpretation of the stress energy momentum tensor

    First, I'd like to thank everyone that has helped me thus far in deriving the general relativistic tensors for the Morris-Thorne wormhole metric in an orthonormal basis. I have finally done it and grasped that concept. Now that I have done that, my new stress energy momentum tensor for this...
  18. F

    How Do I Find Constants for the JC Flow Stress Model in Waspaloy?

    Hi my name is Federico and I'm a student of mechanical engineering and i have to make a research on this material: waspaloy. Now, i have the flow stress model, but i don't have some constant of this equation. In particular , there are a classic JC model where stress is...
  19. R

    Anisotropic Modulus of elasticity and Poisson's ratio

    Hi, I have some experimental data and I am interested to use this data to calculated modulus of elasticiy (young's modulus) and Poisson's ratio. The material for which the data is given in an anisotropic material, therefore I need to calculate modulus of elasticity and poisson's ration is x,y...
  20. davidbenari

    Tensile stress, and youngs modulus.

    I'm studying elasticity right now in my chemistry class, and I'm confused as to what exactly tensile stress (and maybe compression stress too ) might mean. It's given in N/m^2. And you're stretching the material. Is the cypher I'm given indicative of what's happening only one side? Indicative...
  21. D

    Applied shear stress between plates

    Hi :), I need to calculate the shear stress applied between 2 plates and I don't remember how to take the thickness of the plates into account, --So basically I will be grateful if somebody could write the equillibrium for shearing stress between 2 plates (1 plate is applying force on the other...
  22. B

    Stress on a Guitar Soundboard when converting to Tailpiece

    I do have a question on a project that I am doing now (for my personal enjoyment) I bought an nice handmade classical guitar that was dropped on the tail-block and cracking it and putting two nice crack from the end of the guitar to the sound hole. Since I only invested $100 I decided to use as...
  23. S

    Do all elements of the stress energy tensor really have the same units?

    Some people may remember awhile back when I made a thread showing how when I derived the Einstein tensor and the stress energy momentum tensor for a certain traversable wormhole metric, that the units of the energy momentum tensor were not the same for each element and how a couple of the...
  24. Jonathan Scott

    Stress and pressure as gravitational source

    As I'm sure I've mentioned before, I've heard people say that stress and pressure terms in the energy tensor act as a gravitational source, but I don't understand how this could be, given that these terms can simply appear or disappear (in a non-stationary situation), unlike energy and momentum...
  25. N

    How Do You Calculate Elastic Modulus and Strengths from a Stress-Strain Curve?

    Hello I'm having trouble wrapping my head around finding things from stress strain curvesI need to find: Elastic modulus (Young’s modulus) •Yield strength •Tensile strength •Uniform and total elongation (ductility) elastic modulus I think is 1240/0.02 = 62000 but I'm unsure of how to find...
  26. PetePetePete

    Stress and Strain Coursework Question

    I am struggling with a question in my coursework, and would appreciate some guidance. The question is: The component shown in Fig 1 is made from a material with the following properties and is subjected to a compressive force of 5kN. Material Properties : Young’s Modulus of Elasticity – 200...
  27. F

    Solving Shear Stress on a Bar - Mechanics of Materials

    I'm trying to understand a problem found on Mechanics of Materials and did not completely understood the problem. I can solve problems like this but I still don't know why I'm solving this way. It is a simple question: Why the shearing force V does not cause shear stress (\tau_2) on the point A...
  28. D

    Determine freq of AC that induces stress in the specimen

    Homework Statement An electromagnetic fatigue-testing machine has an alternating force is applied to the specimen by passing an alternating current of frequency ##f## through the armature. If the weight of the armature is ##40## lb, the stiffness of the spring ##k_1## is ##10217.0296## lb/in...
  29. Dethrone

    MHB Is my vertical component calculation correct?

    In the structure shown, a cable is attached to the 50 kN weight and to the beam A-D at point B. If the horizontal uniform beam weighs 8 kN/m, determine the following: (a) The horizontal and vertical component of the force that the pin at D exerts on the beam A-D. (b) The force in the cable. ...
  30. D

    Stress in a hollow beam bent laterallly

    I would like to calculate the maximum stress in a hollow beam being bent laterally. There has been some discussion in my office about the correct way to view the system in question, and so would like some other opinions on the matter. I will include pictures below. In simplified terms, the...
  31. E

    Shear stress on a tire from a puddle of water

    Homework Statement A car is moving at 65 mph and hits a puddle of water 1 inch deep. What is the shear stress on the tire from the puddle of water if the radius of the tire is 16 inches. r = 16 inches u = 65 mph y = 1 inch mu = viscosity = 2.344*10^-5 lbf*s/ft^2 Homework Equations angular...
  32. arpansen

    Allowable compressive stress in discretely laterally supported lateral buckling

    The maximum allowable compressive stress corresponding to lateral buckling in a discretely laterally supported symmetrical I beam does not depend upon : the modulus of elasticity can anyone please tell me the reason ?
  33. K

    Stress problem- finding the diameter of a tie bar

    Hello, I'm having an issue trying to solve an equation- the problem is worded as such: "A tie bar is made of a material having an ultimate tensile strength of 231 mPa, and must carry a load of 255 kN. What is the diameter of the bar if a factor of safety of 7 is required?I know that the...
  34. steves1080

    Calculate drag force on a temperature probe inserted in a water pipe

    I'd like to add a temperature probe to a 4" water pipe downstream of a centrifugal fill pump, but I am afraid of the probe shearing from being subjected to a constant force from the upstream pump (which pumps at about 400 gal/min). Naturally, my thought was to use the drag force equation, but I...
  35. S

    Solving Dimensional Analysis Problems in Stress Energy Momentum Tensor

    Recently, I used the metric for the traversable wormhole (the one in this link): http://www.spacetimetravel.org/wurmlochflug/wurmlochflug.html ds2= -c2dt2 + dl2 + (b2 + l2)(dΘ2 + sin2(Θ)dΦ2) I derived the metric tensor from this space-time interval and then from there, I derived the...
  36. B

    Minimum Shear Stress in Hollow Circular Tube

    Homework Statement A hollow pipe has an inner diameter of 80 mm and an outer diameter of 100 mm. If its end is tightened using a torque wrench using 80 N forces, determine the maximum and minimum shear stress in the material. Where are they located? Note: In the diagram of the picture, the...
  37. Dethrone

    MHB What Is the Optimal Geometry for a Concrete Column Supporting 1250 Tonnes?

    When building a tall support, often the self weight of the support must be considered. For an optimal support, the volume of material, and hence the cost, will be a minimum. If the maximum allowable stress in concrete is 15 MPa, determine the optimal geometry of a column 100 metres tall made of...
  38. R

    Beam problem finding max bending stress

    Alright so I drew it out like did the reactions and everything then I realized I need to include the diameter of the beam. How do I find the max bending stress while using the diameter of the beam? All I need to know is what exactly I do differently compared to drawing the bending moment...
  39. E

    Total moment of shear stress about the center line of a cylinder

    http://postimg.org/image/onxjqc26l/ I have found the shear stress of the inner cylinder to be 405 Pa like in the solution but I am having trouble visualizing the total moment of this stress about the center line. I was wondering if someone could explain where that d(theta) in the moment...
  40. Dethrone

    MHB Bridge Question - Stress / Strain

    I have gathered all the information: Span: $1991$ m Breaking Stress: $1770$ MPa Load: $370$ KN/m Drape: $201.2$ m So far, I've found the allowable stress by dividing the breaking stress by the safety factor, which is $787$MPa. Then, I calculated the total load of the bridge, by multiplying the...
  41. R

    Use viscosity/shear stress relations to find torque needed to rotate disk

    The problem asks for an approximation for the torque needed to rotate a disk that is separated from a stationary boundary by a viscous fluid, given that \tau = \mu \frac{U}{H}. I did it first using like this: T = F R F = \tau A = \mu \frac{U}{H} \pi R^2 where U = \Omega R And thus T = \mu...
  42. B

    Stress calculations for acrylic

    I need a formula for deriving the required material thickness for an acrylic panel. The project will involve an acrylic window for a large aquarium. I have included a dimensional rendering. The maximum design stress must be maintained at or below 800PSI. The maximum water pressure...
  43. W

    Why Does My Simulation Not Show Lateral Expansion in a Compressed 2D Square?

    For a while I've been working on applying the finite difference method to various problems and am now trying to get a model of stress and strain working. I wrote a sim a few weeks ago and I got one example to run and thought it was good. Now, I've tried it on another example and I see that...
  44. V

    How to Simulate Residual Stress induced by Friction Stir Welding

    Hello all, I am M.Tech student and doing my dissertation on friction stir welding stimulation in ANSYS Mechanical APDL. I need to simulate residual stresses induced during welding using ANSYS. How can I do the same, please reply. I am a beginner in ANSYS. I don't have much knowledge of ANSYS
  45. W

    What Stresses Keep a Shear-Stressed Block in Equilibrium?

    This is not a textbook problem, instead it is how to understand a common diagram. The diagram occurs in the wiki entry for shear stress http://en.wikipedia.org/wiki/Shear_stress It shows a 2D square, anchored on the bottom side, and with positive (rightward) shear stress applied to the...
  46. Chacabucogod

    Stress of a Rod with angular velocity

    As far as I understand a rod that has an angular velocity is static. Nonetheless, if we analyze a particle in the rod, this particle will be subject to a centripetal force that will be proportional both to the angular force and radius. Now I understand that the external forces and momenta...
  47. S

    Stress and Strain: Understanding Axial Loading

    Im currently studying a course on the mechanics of solids..the reference book i use is by Popov..But i can't completely understand the concept of stress in an axial loading.Like for instance. If a weight W acts on a rod(ignore the rod's weight),stress will vary point to point along the...
  48. P

    Average of Multiple Stress Tensors

    I have a cluster of voxels and a 2nd order stress tensor corresponding to each voxel. I was wondering as to what would be the best method to calculate an average stress tensor for the cluster as a whole? Any constructive inputs would be greatly appreciated.
  49. Ganesh Ujwal

    How to find max shear stress at a given point?

    The state of plane-stress at a point is given by σx = -200 MPa, σy = 100 MPa, σxy = 100 MPa The Maximum shear stress (in MPa) is: A) 111.8 B) 150.1 C) 180.3 D) 223.6 Explain Procedure also with Answer. Attempt: i already used Max Shear Stress τ = QV/ib, then also answer is not matching...
  50. kelvin490

    A question about residual stress

    Shot peening is a process of inducing RESIDUAL COMPRESSIVE STRESS on the surface layer of metal parts. When shooting particles are colliding on the surface of metal there is a compressive stress. My question is, how can resultant compressive stress exists after the force causing the compression...
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