What is Bending: Definition and 665 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.

View More On Wikipedia.org
Recent contents Top users
  1. I

    What determines the starting point of a bending moment diagram?

    In the bottom left, why does the BM diagram start at -4kNm rather than 4kNm? I understand that if you make a cut you yield this result but if you don't make a cut how would you know whether it starts at -4kNm or 4kNm? Thanks
  2. 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...
  3. M

    Reinforce concrete column under biaxial bending

    I've made a program with Mathematica that will compute the load along with the moments sustained by a concrete column given the stress block area and orientation(in other word the neutral axis center location and the angle it makes with the horizontal). However I am facing an issue with setting...
  4. S

    Light bending in the hot plate model of curvature

    Light bending in the "hot plate" model of curvature In the Feynman lectures, feynman describes the hot plate model of space curvature and shows that light is bent around the center of the plate, see Fig. 42-6 http://www.feynmanlectures.caltech.edu/II_42.html#Ch42-S1 However, the hot plate...
  5. A

    Analysis of scoop stretcher - deflection and bending stress help

    Analysis of scoop stretcher -- deflection and bending stress help I wanted to do a theoritical force analysis on the scooping part of scoop stretcher (a tapered rectangular plate). Can anyone suggest how to determine its deflection and bending stress ?
  6. B

    How does bending the time continuum affect time?

    If I am in my office and the space-time continuum is further bent, would I realize that time is passing slower or faster and why?PS: I am new to physics, so please provide a complete answer.
  7. M

    Neutral Axis Calculation for Concrete Columns Under Biaxial Bending

    How can the neutral axis of a concrete column under biaxial bending be determined. I mean if the load P is given along with the eccentricities ex and ey, how could the N.A. location and orientation be computed? Thank you.
  8. J

    Finding the bending moment for maximum stress

    Hi, I am looking to use My/I to find the maximum bending stress for a beam My problem is I don't know how to find the bending moment- the reason why: The beam has more than one point of load, aside from the reaction points. (Pin joint cantilever beam) The sum of all moments equal 0...
  9. J

    Bending Waves, Plate and Beam theory?

    Hi, I am doing research on sound radiation of a plate due to bending waves. I have come across the Kirchhoff Plate theory, Euler beam theory and also the equations for the phase velocity of longitudinal, transverse shear and bending waves. What i am confused about is how these theories and...
  10. M

    Bending Moment and Shear Force Problem

    Homework Statement Hi all, I have a problem determining the moment and shear force at a location. The moment, I think, I have already solved. But I get stuck at calculating the shear force at the same location. It is for a element that is suspended in water, thus the weight of the element...
  11. P

    How Does Mass Affect the Fabric of Space-Time?

    I'll ask that you forgive me if my question seems to "basic" or simple for some of the more professional posters. I am simply a physics/cosmology enthusiast who has been captured by it all since I was a child, however, there is one issue that as I continue to learn more is bothering me. I...
  12. A

    What is the maximum bending moment for this beam?

    Homework Statement Problem: For the beam according to the image, solve graphical and analytical: 1.) Reactions in the supports, 2.) Bending moment diagram, 3.) Maximum bending moment Given variables: F = 14 kN q = 40 N/cm a = 100 cm b = 55 cm l = 180 cm Homework Equations This is a Beam...
  13. B

    Flexural Modulus of a Test Specimen (3-point bending)

    Hello everyone, I need to work out the flexural modulus (Ef) of a test specimen that is subjected to a 3-point bend test. I know that: Ef = L3m/4bd3. I have: Support Span(L)= 0.1m width(b)= 0.01m depth(d) = 0.01m Max normal stress σf= 98.1 MPa Strain (εf) = 0.0525 Max force (applied...
  14. T

    Shear force and bending moment diagrams question

    Homework Statement So in my notes we have the following example: So I decided to try to solve it another way, this time I flipped the figure and here is my attempt: I got the correct moment but then the signs on my shear is flipped. Does anyone know why?
  15. M

    Bending pipe - compression and tension

    Hi, I'm a bit confused. Say you're bending a cylindrical pipe (tube, hollow cylinder). So the neutral axis of the pipe will be in the middle of the pipe and all the material on the inside of the bend (to one side of the neutral axis) will be in compression, while all the material on the...
  16. F

    Shear and bending moment diagram problem

    Homework Statement I have attached a diagram Homework Equations 14 + Va -32 + Vb -15=0?? or Vb=-15? The Attempt at a Solution The reason why I cannot attempt this problem is that I'm not sure whether it is valid that there can be a point load at Support B or whether they are...
  17. S

    Shear Pin Stress Concentration V-Notch vs. U shape grooved in bending

    Can someone link a website or attach a picture of a chart distinguishing the differences between the stress risers in a shear pin (round circular shaft) with a V-notch groove versus if it was a rounded groove. I have been looking but can only find charts, tables and graphs for round circular...
  18. shinnsohai

    ShearForce & Bending Moment Exp

    Homework Statement Recently I am undergoing such experiment in school and my lecturer asked that, as if any changes in the distance(vertically) will there be changes in the force/reading of it?Assuming there is no changes in anything else except the position of the tools. (Since the "Cell...
  19. W

    Bending of a long, thin elastic rod or wire (finding shape & height)

    Hi all, I'm trying to do something that might be impossible, but seems to me should have a solution: Finding the height (or displacement) of a long, thin rod or wire under horizontal compression forces at the ends (pinned, not clamped) causing it to bend into a stable arch-like shape given...
  20. B

    Draw shear force and bending moment diagrams

    Homework Statement For the beam shown in the figure: a) Draw necessary free body diagrams b) Calculate support reactions c) Draw the shear force and bending moments Homework Equations ∑Fy = 0; ∑M = 0; V(x) = ∫ L(x) ; M(x) = ∫ V(x) The Attempt at a...
  21. M

    Shear Force and Bending Moment Diagram

    Homework Statement This is the question that I am struggling with. http://postimg.org/image/5kb0pur3z/ I need to plot shear force and bending moment diagram of it.Homework Equations The beam is in static equilibrium so algebraic sum of forces in x and y direction equal zero. Also, moment is...
  22. T

    Elastic postive bending moment

    Hello I just joined this forum and this is my first thread here. This is my assignment question. I'm supposed to find elastic positive bending capacities around the horizontal axes for the following cross section shown in pic. The elastic stress in tension is 10 ksi and in compression is 15...
  23. S

    Shear force while bending a metal rod

    Homework Statement Let me first add a picture of the experiment and than try to describe my problem: So I have two rods (one with a square profile and the other one with a circle profile) and what I do is I apply some force in the middle. The rod bends under the applied pressure...
  24. B

    Derive an equation for the maximum bending moment

    The calculation for the maximum bending moment is to be verified experimentally using a strain gauge bonded to the outer surface of the beam, at the point where the maximum bending moment occurs. Derive an equation which could be used to calculate the bending moment from the measured strain...
  25. R

    Calculating Bending Moment and Microstrain in Hollow Circular Beam

    Homework Statement Hollow circular beam with outside diameter 350mm, and wall thickness of 60mm E=60 Gpa beam length 2m Force applied to beam at midpoint of beam (1m from each end) F=200KN Force applie from the Top down, Ra , and rb from bottom up Homework Equations...
  26. J

    Calculating maximum bending stress in an I beam?

    Hello all, I am confused on how to calculate the maximum bending stress in an I-beam. I found the maximum deflection in each beam where the load is placed at the center of the span. I also know all the cross-sectional dimensions of the I-beam. Is it now possible to calculate it? Thanks
  27. shounakbhatta

    Bending of Light: General Relativity Explained

    Hello All, Kindly apologize if this question sounds rudimentary. General relativity which shows the bending of light. Is it due to: (a) Spacetime is curved due to massive objects and when light passes through that object, facing the obstruction it bends? (b) There is as such no force...
  28. N

    Help with understanding Shear Force and Bending Moment

    Homework Statement What is: i) In diagram 1, the magnitude of the normal force at A ii) In diagram 2, the magnitude of the shear force at B iii) In diagram 3, the magnitude of the bending moment at C iv) In diagram 4, the magnitude of the bending moment at the support...
  29. O

    Derive an equation which could be used to calculate the bending moment

    Homework Statement The calculation for the maximum bending moment is to be verified experimentally using a strain gauge bonded to the outer surface of the beam, at the point where the maximum bending moment occurs. Derive an equation which could be used to calculate the bending...
  30. 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...
  31. R

    Floor Loading - Bending Moment?

    Homework Statement I'm trying to find the bending moment on beam CE in the attached problem. There is loading from all 3 floor slabs. I'm struggling to figure out the maximum bending moment at mid-span because the 2 distributed loads from the 2 smaller slabs are not uniform as such...
  32. N

    Comparing structural bending strength

    Hello, Not sure how to go about solving this problem: What outer diameter must a 2mm thick hollow rod have in order to have the same structural bending strength as a solid rod with diameter of 7mm? Also compare the weight per unit length of the two rods. Assume that material is stainless...
  33. L

    Calculate strain from bending moment?

    Homework Statement Simply supported beam, all values known now I believe as this is the last question on it. I have spent a long time trying to work this out: The bending moment is to be verified using a strain gauge bonded to the outer surface of the beam at the point of max bending...
  34. H

    What is band bending and how does it relate to Fermi Energy?

    Homework Statement Consider a pn junction in Si at 300K (other parameters given), with doping NA = 1021/m3 and ND = 1023/m3. Assume all impurities are ionized. On this basis find the Fermi level on each side. From this find the band bending VB and make a sketch of the pn junction. Homework...
  35. B

    Bending moment of square tubing

    I have some square tubing 3x3x1/4" A36 that will be fixed on one end and free on the other the material 9' long how was I find the bending moment?
  36. H

    How to determine the maximum bending moment of a beam

    I have a 1.5m beam with a uniformly distributed load of 57kn/m acting over 1.2m of the beam (0.6m from the centre of the beam in both directions). I require the maximum moment and the deflection of the beam. I know the maximum moment equation wl^2/8 and the deflection formula 5wl^4/384EI...
  37. B

    Normal and shear stress distribution due to shear force and bending

    Hi guys, I have a repeat exam in 10 days and I have a couple of things which I would appreciate if you would help me with. I have attached the mock exam and my attempt at question 2. I will describe where I have issues below. Homework Statement For the FIRST question, I have the...
  38. Y

    Statics: Shear and bending moment, distributed load

    Homework Statement Homework Equations ƩFy=0 ƩM=0 The Attempt at a Solution Finding the reaction at A: ƩFy=0: A + (L*w0)/6 - (L*w0)/2 = 0 A = (L*w0)/3 ƩMA=0: MA - [(L*w0)/2]*(L/3) + [(L*w0)/6]*((2L)/3) = 0 MA = (w0*L2)/18 For the shear and bending moment: ƩFy=0: (L*w0)/3 - (x*w0)/2 +...
  39. P

    Design experiment to determine bending strength and torsion of ruler

    hello everyone! so as the title suggest, i wonder if anyone would have any idea to design a simple experiment to determine the bending strength and torsion of a plastic ruler. it doesn't need to be extensive, as the value of the strenght itself isn't important. i just want to know e.g how...
  40. 1

    Band Bending at SiO2 Interface

    Hello everyone ! In below picture we can see band bending in semiconductor at SiO2 interface, as show in picture how charge's BE(binding energy) and KE(kinetic energy) are changing..?? Or what happens to charges total energy in band bending ..?? \\
  41. C

    Compression and bending on a cross section,how to make sure its static

    The problem is the following, i have a rectangle as a cross section of steel, which is bended and compressed.. i want to use the equilibrium equations to make sure its static, but since the compressive force and the traction force aren't equal, the equilibrium equations make no sense here's a...
  42. R

    Shear Force and Bending Moment Diagrams

    Hello all, I'm having some difficulty understanding the relationship between the diagrams. I understand that the area under the shear force diagram curve is equal to the moment. But let's say you have a cantilever beam, 10 m long, anchored on the left. There is an evenly distributed load...
  43. M

    Torque of human arm when bending

    To find the respective torque that is need to bend the the arm at 180 degrees, 90 degrees and 30 degrees. The arm is not holding anything. Relevant equations and information τ=rFsinθ total arm weight =3.35kg upper arm length =19cm forearm length =28cm
  44. S

    Minimal Dimensions for Maximum Bending Moment

    Hi Please can someone help me calculate the minimal thickness and width that will resist bending in each of the aluminium beams that are fixed on one end and support a 0.0013734 Newton load on the other. The axis passes through the center of the octagonal shape and goes into the page...
  45. F

    Determine the bending of a bar

    Homework Statement Hello, i have problem with the following: Determine the bending of the free end of an adjacent bar. The bar have flexural rigidity EI Picture: http://s716.photobucket.com/user/Pitoraq/media/Kon2_zps02951d5f.png.html?sort=3&o=0 Homework Equations q = -dt/dx =...
  46. I

    Wire With Greatest Bending Fatigue Resistance

    I need to add flexibility to this joint (where the arrow is pointing) and I was thinking about using a method I saw on this flexible clamp. I ripped it apart and it looks like they used copper wire as the flex material. What would be the best wire to use? I'm worried that perhaps it could...
  47. G

    Bending energy for a rod/column under compression?

    Hi, I would like to calculate a bending energy of a circular rod. It should be elastic bending. The rod/circular column should be loaded with some point load force at it's top. Any amount could be used, for example F=1,10,100 kN... I know how to calculate a strain energy of a rod loaded...
  48. S

    How Do You Derive the Bending Moment Distribution for a Beam?

    Homework Statement Derive the bending moment distribution of the beam: Homework Equations The Attempt at a Solution I end up with something like this: Im abit concerned with the profile, should it taper to zero? Any thoughts? Thanks
  49. S

    Mass bending space makes me think there's another side to space

    Mass bending space makes me think there's another "side" to space Perhaps I'm not understanding space curvature very well, but how could it curve if the universe, or space, is an open system? If mass is bending it, this makes me believe the universe is a limited and closed system. In other...
  50. J

    Bending power - magnet units question

    I am reading a paper where the bending power of a dipole magnet is described as 2 Tm. Is that Tesla*meter? Is bending power actually power i.e. Work/Time? Can someone explain this physical quantity to me, please?
Back
Top