What is Bending stress: Definition and 52 Discussions

In applied mechanics, bending (also known as flexure) characterizes the behavior of a slender structural element subjected to an external load applied perpendicularly to a longitudinal axis of the element.
The structural element is assumed to be such that at least one of its dimensions is a small fraction, typically 1/10 or less, of the other two. When the length is considerably longer than the width and the thickness, the element is called a beam. For example, a closet rod sagging under the weight of clothes on clothes hangers is an example of a beam experiencing bending. On the other hand, a shell is a structure of any geometric form where the length and the width are of the same order of magnitude but the thickness of the structure (known as the 'wall') is considerably smaller. A large diameter, but thin-walled, short tube supported at its ends and loaded laterally is an example of a shell experiencing bending.
In the absence of a qualifier, the term bending is ambiguous because bending can occur locally in all objects. Therefore, to make the usage of the term more precise, engineers refer to a specific object such as; the bending of rods, the bending of beams, the bending of plates, the bending of shells and so on.

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  1. S

    Engineering Crane at 45-degree angle supports load -- Find principal boom stresses

    The book's answer key shows a normal stress P/A as a result of adding the 350LB force from the cable to the cos(45 degrees)(350LB). It shows both of these as compressive forces. I can see how the cos(45 degrees)(350LB) is compressive; the force of the 350LB load is bending the boom clockwise...
  2. D

    Lewis Bending Stress: Why Does Lewis Factor Depend on x?

    How come in the lewis bending equation for spur gear tooth does the lewis form factor depend on x? x being the vertical distance measured from the triangle that is formed from the base t and fillet a. I know that you can express the height h and width t in terms of x such that x= t^2/4h, but why?
  3. G

    Out-of-plane bending stress on an I-beam

    I know the out of plane bending stress equation for a curved I beam but I am trying to figure out where it came from. sigmaR = tFlange * sigmaNormal/(radius of curvature)
  4. T

    Bending Moment & Bending Stress

    Hello all I was wondering if anyone could figure out the what the equation below means, specifically the W term? The equation to calculate bending stress for a cross section that i have used and i know is correct is:- Bending Stress = Moment (M) * Distance From Neutral Axis (Z) / Second...
  5. T

    Calculating the bending stress of a simply supported beam

    Hello all I am trying to calculate the bending stress of a simply supported beam with a load of 12kn at the middle of a 6m span, member depth of 0.016m I have drawn both the bending moment and shear force diagram. I want to know the following:- 1) When calculating the bending stress would...
  6. dustball23

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  7. Joe591

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  8. J

    What are other names for bending stress?

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  9. Jesse Niekamp

    Bending Stress on a Protective Cover

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  10. K

    Parallel Axis Theorem / Bending Stress

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  11. D

    Applying Bending Stress to a Model of Ship Section

    Good Afternoon. My name is Dimas M. Rachman, i am an undergraduate student majoring in Ocean Engineering/Naval Architecture. I am currently working on my final project. I need to model the effect of bending stress "inside" a plate of ship's deck with Ansys Workbench. Here is a review about...
  12. S

    Tube Bending Stress: Hand Calcs vs FEA Analysis

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  13. F

    Moment applied causing bending stress in beam

    Homework Statement From the solution , it's clear that the top part of the beam undergo tension , while the lower part undergo compression . Homework EquationsThe Attempt at a Solution But , i don't understand why it is so . When the moment is applied in the horizontal axis , the structure...
  14. N

    Calculating Bending Stress for a Cantilever Beam

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  15. C

    Understanding the Difference Between Bending Stress and Normal Stress in Beams

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  16. S

    Determine the absolute maximum bending stress of the beam.

    Homework Statement If w = 74 kN/m , determine the absolute maximum bending stress in the beam in MPa. Homework Equations I'm not too sure how to go about my calculations. Please help! The Attempt at a Solution I = [(1/12)*(200*256^3)] - [(1/12)*(192*250^3)] = 29.62*10^6 F = 74*24*1000? [/B]
  17. A

    How can I get the force from the bending stress

    Hello all, I am a new member of PF.I have a basic question about the bending stress, I remember somewhere I saw this part, but can't find out it. Could you give me a answer? Given: 1, M-moment applied on the section. 2, I-Section modules 3. y-distance from shear center Solution F,how much is the...
  18. R

    Calculating bending stress for pipes

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  19. J

    Question about the location of max bending stress in a beam

    Hello guys, I have a simple question about the max bending stress in a beam. We know that in a cantilever beam, the biggest moment occurs at the wall. This is also the location of the max stress with equation stress= M*y/I , However, in a simple supported beam, we have This time, the max...
  20. G

    Can Bending Stress on Curved Beams Be Calculated Using a Simple Formula?

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  21. DrVirz

    Where is the point of maximum compressive stress in bi-axial bending?

    Hi all, I've attempted this question however my solution seems too simple..? I have taken the point 'A' (bottom right corner of beam) as the point with max compressive stress, I am not sure if this is correct. I have just assumed this by observation.
  22. T

    Explaining Bending Stress in Cantilever Beams

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  23. spikeybrummy

    Convert solid shaft to hollow shaft

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  24. T

    Tensile Strength & Bending Stress of Metal Sheet

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  25. 1350-F

    Brittle Materials: Bending Yield Strength

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  26. T

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  27. G

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  28. K

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  29. 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...
  30. J

    Structural Mechanics. bending moment and bending stress

    [b]1. Homework Statement [b/] A timber beam, with rectangular cross section (h × b) is reinforced with additional full width (b) steel plates. There is a plate of thickness t securely connected on the bottom and a plate of thickness 2t on the top of the timber to ensure composite action in...
  31. A

    Analysis of scoop stretcher - deflection and bending stress help

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  32. J

    Calculating maximum bending stress in an I beam?

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  33. J

    Bending stress due to 2 bending moments in different planes

    1. The scenario is the same as this (with a circular cross section): http://upload.wikimedia.org/wikipedia/commons/c/cf/Poutre_flexion_deviee.svg 2. Do I simply calculate the stresses from each bending moment and add them together? Or take the resultant vector and calculate...
  34. M

    Calculating Maximum Bending Stress of a Beam

    A uniform simply supported beam, 5 m long and having a cross-section as shown, is to support a load which varies linearly from zero at the left hand support to a magnitude of 20 kN/m at the right hand support. Determine the position and magnitude of the maximum bending stress. ANS : 140 MPa...
  35. S

    Length & Bending Stress: How Does Beam Length Impact Stresses?

    if you have a beam or something, anchored at one end and apply a moment at the other end, then the bending stress is given by M*y / I, where I is the moment of inertia of the beam. what affect does the length of the beam (i.e. the distance between the anchor and the end of the beam, where the...
  36. C

    Determine bending moment and bending stress

    Homework Statement A timber beam, with rectangular cross section (h × b) is reinforced with additional full width (b) steel plates. There is a plate of thickness t securely connected on the top and a plate of thickness 2t on the bottom of the timber to ensure composite action in bending. The...
  37. F

    Understanding Moment of Inertia and Bending Stress in Physics Forums

    hi all , I am a new member in physics forums and I hope I can help and get benefit from this forums . I would ask anyone knows about the moment of inertia cos i have not study it before and I have to know it to solve a bending stress problem .. when I used the moment of inertia for...
  38. M

    Maximum bending stress in wooden beam

    Homework Statement A timber beam will be used to support part of the ceiling of a house. It is going to be attached to the walls as a simply supported beam, Figure 6. If three forces are applied to it and considering the weight of the beam as a uniformly distributed load of...
  39. K

    Bending Stress Help: Find Resources Here

    Hello guys. I need help to understand the calulation of bending stress. This topic is discussed in our lecture, and the prof shows us an animation for it. However, this topic is not on the textbook and the prof refuse to give us the link for the animation. I am wondering, do any of you know...
  40. G

    Help me calculate a calculated bending stress (psi) in cantilever beam?

    Homework Statement I am using a Vishay strain indicator with it hooked up to a strain gage hooked up 1" away from the wall on the solid beam. The beam is .5" by .5", and it is solid. The beam is 16" long and I am putting weights at the end of the beam. The weights are 1, 2, 5, 10, 15, and 20...
  41. G

    Bending stress in gear/bearing puller

    Homework Statement I have a project where I have to determine the bending stress on a gear/bearing puller. It looks like this: http://www.posilock.com/PDFs/106.pdf . The free body diagram I'm pretty sure would look something like this: http://img20.imageshack.us/img20/1918/fbdi.jpg...
  42. G

    Local bending stress calculation in long beams

    Hi everyone, Recently I faced a problem in calculating bending stress in a long UPN profile "flange" due to concentrated force. It seems that the regular/familiar formula for bending stress in a finite/short element does not applicable in local bending of long/infinite beam. See sketch...
  43. P

    How can I estimate the bending stress for a hollow tube under uniform load?

    Dear All, Please see the picture. I need to find the bending stress for that profile. Its hollow tube dia= 38 mm, 4 mm thick. its is acted with udl of 500 N/m2 on its outer surface. How can I estimate the bending stress, deformation. Assume it as mild steel with E = 200 Gpa, poission...
  44. E

    Is max bending stress the same as the yeild strength

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  45. O

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  46. S

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  47. A

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  48. J

    Maximum Bending Stress in Beam

    Homework Statement Note the attachment. I scanned it out of my book and I drew a FBD on it. Homework Equations The Attempt at a Solution Ok so i haven't gotten very far at all with this one because it just doesn't seem to have enough information. So first I summed the forces...
  49. N

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  50. C

    Bending stress of beam on flat surface ?

    I am designing a spinal disc with 2 metal endplates. These endplates are rectangular in shape and are fixed to form a flat contact surface with the vertebrae bone surface. My question is based on the bending stress of these metal endplates. I need to work out the possible thickness of these...
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