Strain Definition and 413 Threads

Homework Statement Each year, 5.7% of archers develop repetitive strain injury (RSI) in their arm. Each year, 3.6% of archers develop problems related to eye strain. However, 91.2% of archers develop neither. (a) Formally define sensible event notation, and summarise the information in the...

Homework Statement The Attempt at a Solution http://imgur.com/3ZfjPxM.png So if you look at my attempt, I integrated the strain energy density function and at the end everything cancels out. Does anyone know what I did wrong?

Homework Statement I need to find the total strain energy in the beam with a moment applied: The Attempt at a Solution For my attempt I decided to split the integral into two parts since the moment is different depending on whether or not you are on the left side of the moment or on...

I've been tasked with designing an experimental rig for some students and have run into a bit of a cul de sac with this particular issue. Allow me to elaborate: A beam of known geometry (length, depth, width, etc.) is being bent over a hollow cylinder. The beam has holes machined through at...

When a bolt is pulled in tension and eventually fractures, is all the built up strain energy dissipated in the formation of the new surfaces? Does any energy do into accelerating the broken halves of the bolt? Imagine that two plates are bolted together. As the two plates are forced apart...

I'm trying to compute lateral strain for a bar (strain that would make it thicker, or have more cross sectional area). All I know are the initial and final diameters. This gives me d1 and Δd. Would the lateral strain be Δd/d or ΔA/A? (A is area)

I have an assembly of two 2D surfaces. I modeled it on SolidWorks however, I could not import it to Ansys in any format. I tried SLDASM, Step and IGES. I tried modelling the same on Workbench modeller. However, I could not figure out a way to model 2D assemblies on the modeller. Can someone...

A compound bar is made using stainless steel tube with an aluminium alloy bar positioned concentrically inside it, and rigidly fixed at each end. The cross sectional area of the tube is 400mm^2 and the cross sectional area of the bar is 300mm^2. The combination is in tension and limiting stress...

A light alloy bar is observed to increase in length by .35% when subjected to a tenstile stress of 280MN/m^2. Calculate youngs modulus for the material. σ=280MN/M^2 x=.35% ε=? E=? L=? I have too many unknowns where do I start?

In my text it's given when a cube underwents a uniform unit tensile force be applied in all six faces, bulk module=1/3(α-2β) Where α is longitudinal strain and β is lateral strain.is there a derviation for it..? And it states in x direction there will be increase in length and in y, z...

I know that I'm wrong but couldn't find where I'm Stress=internal force /area When the body is in equilibrium, force applied equals internal force.therefore stress=force applied/area Let us stretch a rod by two equal and opposite force.,say f and -f...thus total force is zero Stress=...

Homework Statement A tunnel of length L = 151 m, height H = 7.7 m high, and width 6.2 m (with a flat roof) is to be constructed at distance d = 60 m beneath the ground. The tunnel roof is to be supported entirely by square steel columns, each with a cross-sectional area of 960 cm2. The mass of...

Hi all, This is a question regarding stress and strain. Can someone please explain the concepts of stress and strain in atomic level? My understanding is as follows.Let us consider a metal bar or rod that is subjected to tension.The load applied to the bar will be try to elongate the...

Hi all, This is a question regarding stress and strain. Can someone please explain the concepts of stress and strain in atomic level? My understanding is as follows.Let us consider a metal bar or rod that is subjected to tension.The load applied to the bar will be try to elongate the...

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...

Homework Statement I am doing a lab. My textbook defines strain as ε= lf-lo and E = σ/ε. In my lab, E= σy/εy. εy = ΔLy/lo I do not understand how they can both = ε as lf-lo is completely different from ΔLy/lo. ΔLy is "elongation at yeild" according to my lab. Why are they both labelled E...

I studied that Stress is defined as Force per unit area. Force here referred to internal force between the particles in the materials per unit area. am i right? Is pressure a kind of stress? (Internal force per unit volume) for fluids but i have studied that pressure is external force per...

I am busy studying engineering and I have a subject that requires us to design and build a working instrument using strain gauges. We have a workshop at our disposal and all necessary materials and electronics. At this moment my group and I are stuck with coming up with an idea for an...

Hello, I'm new here and that's because I've run into a problem I can't reliable find anywhere else. I guess I need some personal experience or input from someone. I'm designing a force sensor for a project of mine, it will be measuring force in three orthogonal directions. Now, I'm confident...

Hi all, I am trying to wrap my head around this and for some reason I am blocked. I have taken Solid mechanics and strength of materials and am always used to calculating strain as ε=ΔL/L. I might be missing something easy as it has been a year since the class but in my Manufacturing...

Hi all, This is my first post in PF I'm doing my ninth standard in India,My knowledge in physics is limited so please forgive me if I ask something basic Can anyone clearly explain me the relationship stress and strain,because I thought when a material deforms (even to the slightest...

I've got a problem regarding tensors. Premise: we are considering a fluid particle with a velocity \mathbf{u} and a position vector \mathbf{x}; S_{ij} is the strain rate tensor, defined in this way: \displaystyle{S_{ij}=\frac{1}{2}\left(\frac{\partial u_i}{\partial x_j} +\frac{\partial...

Hello, I am doing simulation using Finite element for the concrete ,this I found the concrete model for the concrete in euro code as attached in the picture. But what I don't understand is basically why the peak of the curve is not the Fck (compressive strength), because the curve maximum is...

Homework Statement Here is a picture of the problem: http://imgur.com/Ldw1fUF Make sure to click on the picture to make it bigger!Homework Equations The strain/hooke's law equations.The Attempt at a Solution I have this for two parts. The second part is the deformation which I got right. I am...

Recently I review some old text and browse around the internet to read about definition of strain and stress. I come across the following document http://web.mit.edu/emech/dontindex-build/full-text/emechbk_4.pdf Previously I have been facing difficulty trying to come out with an...

I've recently done an experiment where I've obtained the strain of a channel section beam in bending. I used a strain gauge to get the strain from the midspan and also used dial gauges to get the deflections of the beam under different loading conditions. Along with the readings I've...

Thanks in advance to any help on this: I am working in a combustion lab and we are designing a high pressure tube reactor. My background is only in math and I have never taken a materials or design course before, so I apologize that this is probably a very basic application and a very...

How can I calculated the wood strain in compression to plot it with stress, if the data that I have is the length and several extension data. The extension data corresponds since the 0 load to the the failure. Thanks. Since the equation for Strain is: ΔLength/Initial Length In order to...

Homework Statement A spring hangs vertically from a fixed point. When a mass of 94g is suspended from the spring the spring stretches by 2.6 cm before temporarily coming to rest. Determine the extension of the spring at which the strain energy is half its maximum value. Homework Equations...

Homework Statement A sphere of mass 0.1 kg is pushed against a rubber band catapult with a force of 80N, and released upwards. Calculate: A) The strain potential energy when stretched by 0.3m B) The work done by the applied force C) The speed of the sphere when released D) The...

Firstly, does a stress vs. strain graph for a material always take the same general shape as its load vs. extension graph (with the same important points, e.g. UTS, having the same shape and corresponding to the same thing)? Secondly, what do the stress-strain and load-extension graphs look...

Do either of these actions impact upon the elastic modulus? I can't think of any reason why they would, but just want to make sure. Thanks.

Homework Statement Explain in terms of stress and strain what happens to the stretched material beyond the ultimate tensile stress. Homework Equations A curve similar to this The Attempt at a Solution I can see that the curve beyond UTS represents increasing stiffness but i can't...

After a fall, a 77 kg rock climber finds himself dangling from the end of a rope that had been 15 m long and 9.1 mm in diameter but has stretched by 2.3 cm. For the rope, calculate (a) the strain, (b) the stress, and (c) the Young's modulus. strain = ΔL/L stress = F/A Young's modulus =...

Homework Statement For each material calculate the cross sectional area in m². Each sample is of rectangular cross section 20mm by 1mm. Produce Stress and Strain tables for the data. TEST DATA FOR X (N) EXTENSION (mm) 1000 0.48 2000 0.60 3000 0.70 4000 0.80 Homework...

Homework Statement Knowing that the stress and strain for an isotropic media can be related with the following expressions: \sigma_{xx} = (\lambda + 2\mu)\varepsilon_{xx} + \lambda\varepsilon_{yy} + \lambda\varepsilon_{zz} \sigma_{yy} = \lambda\varepsilon_{xx} + (\lambda +...

A 1.80-m long round steel wire with a cross-sectional diameter of 0.80 mm is placed over a light frictionless pulley, with one end of the wire connected to a 23.0-kg mass and the other end connected to a 14.0-kg mass. By how much does the wire stretch when the masses are in motion? S= F/A e=...

If a shear force is acting on a rectangular beam, how do I use the value of the shear modulus to calculate if the force applied will fracture the beam? Below I've submitted the data involved. The shear force applied is 1000 N and the cross section area is 28 mm. So the shear force applied is...

How would a strain gage be set up (on top of the model? around the sting?) to measure drag? I don't quite understand the connection between the force of drag and some sort of compression/tension force...? Thanks for the clarification.

Hello everybody, Can you please tell me what's the difference between plane stress and plane strain ? Does one imply the other ? For example, does plane stress imply the plane strain ? Thank you in advance.

HAI I am SYED , i am doing my project using strain gauges. Problem description: I have 4 strain gauges bonded to an octagonal ring. The strain gauge i am using is METAL FOIL TYPE , GF(gauge factor) -2 and 320ohm resistance. The strain gauge has two terminals ,my question is (1) Can anyone...

In a delta strain rosette problem if normal strains are given and asked to find the six components of stress and strain , is it considered as a plain stress or plain strain problem.??

Hello Team, I have a rubber (harness A of 54 and elongation at break of 100%) on which 30N of force is applied over 45mm2 of ares. I would like to know the strain induced in the rubber against the force. The problem here is i could not find the exact Young's modulus value for this material. But...

Sorry for the inverted picture... "y" axis: top to bottom is 500 400 250 "x" axis: at B is .00125 at E is .05 modulus elasticity is E=200GPa so from AB=.00125 from CD=.002 calculated: epsilon=400x10^6/200x10^9 I need to find permanent offset(AC) and I don't know How to find the...

Homework Statement See attachment Homework Equations eAB=(Lf-Lo)/(Lo) The Attempt at a Solution Ok, this is not for HW. I am preparing for a mechanics of materials class next semester. I don't understand when CB goes through the 0.3 degree arc, they say the height is still 300mm. Shouldn't...

A 25mm diameter solid circular section bar made from given material tested is to be bored axially to produce a cylinder of uniform thickness. If this cylinder is then subjected to an axial tensile load of 75kN, what is the maximum diameter of the bore possible if the stress in the cylinder is...

Hello .. I have problem understanding how to decide which material is more elastic based on stress strain curve.. my understanding is as follows 1)if a material has big youngs modulus.. then it is more stiff 2)a material with a big youngs modulus may be or may not be very elastic (elasticity...

1. Knowing that a 0.5 mm gap exists when the temperature is 20 degree celsius, Determine the tempature at which the normal stress in the aluminum bar will be equal to -90 MPa,And the corresponding exact length of the aluminum bar. The Attempt at a Solution I am not familiar with this topic...

http://imgur.com/SnHyP What are the mathematical steps and assumptions to reach the conclusion that length(ab) ≈ dx + ∂u/∂x*dx ? If you consider the the squares of the gradients to be negligible, you still have a square root and multiplication by the constant "2". What other assumptions do...

http://imgur.com/SnHyP What are the mathematical steps and assumptions to reach the conclusion that length(ab) ≈ dx + ∂u/∂x*dx ? If you consider the the squares of the gradients to be negligible, you still have a square root and multiplication by the constant "2". What other assumptions do...