Stress Definition and 1000 Threads

Stress -- Cross-sectional and Inclined planes As per attachment... "On the cross-sectional plane mm the uniform stress is given by P/A, while on the inclined plane mm the stress is of magnitude P/A'. In both cases the stresses are parallel to the direction of P." The parallel part...

Is anyone familiar with the Roark's text that can clarify some terms for me? I am trying to clarify what Roark is referring to in the above mentioned text in the section on short beams (in the 5th edition 7.10 and in the 7th edition 8.10). Throughout the text, he uses the terms "span" and...

Homework Statement Here is the question with the solution: The Attempt at a Solution I understand the first part where they find the forces by summation of moments. However I don't understand how they got that area. Why would they take the diameter (0.016) and subtract it from the length...

Does anyone help me to solve this problem in the attached file? When I solved this problem, I got wrong answers. Attached file is the image file with the problem and answer. (Question No.3) I think I have to find allowable shear stress of Pin A to find the safety factor of this pin...

Hello, I'm new here and so if I've put this in the wrong section or anything, please let me know and I'll fix/change whatever needs to be done. I just wanted to see if someone could help me understand something. When choosing a torque value, is it just ~90% of the yield stress of the...

Homework Statement The 2000 mm long composite bar shown in Fig. 1 consists of an aluminum bar having a modulus of elasticity EAl = 70 GPa and length LAl = 500 mm, which is securely fastened to a steel bar having modulus of elasticity ESt = 210 GPa and length LSt = 1500 mm. After the force P...

i am not able to understand how, where and why stresses will act on the space elevator considering it to be a rope or ribbon, i mean to ask that if we make a free body diagram of the space elevator then where and in which direction forces will act on it. and why that forces will act as they...

A Book says, " When a load is acting on a member, it undergoes deformation. An internal resistance is developed against deformation by the member and the intensity of this internal resistance is called stress." I also read, "When a member is in its elastic range, it offers resistance against...

Homework Statement http://img842.imageshack.us/img842/9577/stresstensor.png Homework Equations 'traction vectors' are just the rows of the stress tensor. that is, the first row of the stress tensor(the i-component of the tensor) is the first traction vector, second row is the second,etc...

Hi guys. Just out of curiosity I want to know that why the concept of stress evolved? Why do we need stress?

Question The compound bar is composed of Aluminium surrounded by High Density Polyethylene Al= E = 69x10^9 Pa Al= r = 0.035 m HDPE= E = 0.8x10^9 Pa HDPE= r = 0.055 m The compound bar has a load of 75000N applied evenly to each of its ends. Part 1. Find the change in...

Dear all, Welcome to this post. I have a question. I have a main piping loop around a cylindrical vessel for which stress analsysis is don't and supported properly. Additonal six loops are to be installed in that main loop. This additional weight is coming on the main piping loop. The...

Hi all, I am currently studying civil hydraulics in my civil engineering course and we are going through estimating critical shear stresses for sediments. I am confused about the difference between boundary shear stress and particle shear stress. In terms of estimating critical shear stress...

Homework Statement A three-legged stool has one leg of aluminium (E = 7 x 1010 Pa), one copper (E = 11 x 1010 Pa) and one of steel (E = 20 x 1010) Pa. The legs have the same dimensions. If the load on the stool is at the exact center, a. Which leg is under the greatest stress? Explain why b...

I'm sure there's a trivial explanation for this, but it's escaping me. The space-space components of the stress-energy tensor are interpreted as the 3x3 stress tensor. But WP claims that the symmetry of the stress tensor need only hold in the case of equilibrium: "However, in the presence...

Homework Statement Calculate stress in a curved beam and compare with FEA model. Homework Equations Stress = (M*(r-rn))/(Aer) The Attempt at a Solution I used the above formula, which is repeated in many textbooks and reputable engineering websites, to calculate stress in a...

When a bar is heated evenly, and it expands freely, they say it has zero induced stress. How about the stored energy? Isn't some energy stored in the process of expansion? Can this energy be calculated the same way the elastic energy is calculated? If so, why we state that it has zero stress...

From what I know the equation for calculating flexural stress of a beam with a rectangular cross section is: 3PL/2Bd2 I have two questions about the validity of this equation. I will post a pic I just made to show what I mean: 1st question, Does this equation work both for filled beams...

Everyone knows college is tough. My professer suggested to me that I should daily do some strenous exercise for at least half an hour. I think he gave that suggestions, so that I could reduce my stress level and after exercise my brain will be fresh so I could study better. I on the other hand...

What's the best way to do Finite Element stress analysis? By that, I mean I'm looking for the best set of general fundamental assumptions to start with. In your opinion. I ask because I'm trying to write a computer code in Matlab that I can use as a general tool for who-knows-what sort of...

Hey guys I am working on stress analysis for a pipeline and I need information on one of the pumps on site ,Gorman Rupp type 06B3-B type… For that I need to find allowable nozzle end loads as per design code used on these pumps. I cannot seem to get through to the technical guys at Gorman...

Hi all, I did simple problem, in which assembly is subjected to single load & it is fixed at other end. I used Higher Order Tet element (& tried with Hexdominent Method also) for the casting body. The vonmises stress shows the true results but when i was looking for the Max Principal...

I was working on a question where I had to find the maximum shear stress in a I-beam due to a shear force applied on it. Heres the question : An I girder 600 mm x 300 mm has flanges 25 mm thick and a web 13 mm thick. Find the maximum shear stress due to a shear force of 500 kN and compare this...

Homework Statement The material for the bolt shown in the angled joint above has an ultimate tensile strength of 500 MPa and a shear strength of 300 MPa. The diameter of the bolt is 8 mm. Determine the factor of safety in operation. Homework Equations The Attempt at a Solution...

My resident theoretical physicist, who I love dearly, is often very distraught. He describes his days of wracking his brains as painful, unproductive, and, at worst, a tedious backtrack through a bunch of stuff that he got wrong and must redo or unthink. Please help me to understand what he...

This is the my homework.Who can solve this for me ? i upload my solutions and the problem .Thanks.

Compute the maximum longitudinal force that may be supported by a bone before breaking, given that the compressive stress at which bone breaks is 2.00e8 N/m^2. Treat the bone as a solid cylinder of radius 1.55 cm. The attempt at a solution I tried using the equation Max Torque = pi/4 * (r^3) *...

Hi guys i have a exam coming up soon and stress is starting to kick in. I am good with stress and strain, but I am just confused on this question and don't understand what i need to be doing. I've tried every formula and i just can't seem to get question 5 out. The answears for this question is...

Hi guys i have a exam coming up soon and stress is starting to kick in. I am good withy stress and strain, but just confused on this two questions and don't understand what I am doing wrong. I've tried every formula and i just can't seem to get question 6 out. And question 5 same problem i...

Hello, first of all I apologize if there is already a topic with this solution but this is my first time here, and I'm a little lost :frown: I'm developing a work which consists in the determination of residual stresses due to TIG welding. I have developed the model and ran a successful...

Hey guys! I'm really stuck and would be grateful for any help. I'm a postgraduate researcher, though not a physicist so this may be a relatively simple problem for some of you (I hope!). I use a program called Bluehill which is coupled with an Instron machine. The instron is a mechanical...

Homework Statement Given in uploaded file Homework Equations σallow=\frac{P}{A} τallow=\frac{V}{A} The Attempt at a Solution Given in uploaded file Answers are d=16mm, h=10mm I tried using methods used in previous questions but it didn't work out for me here, if anyone could...

Hi All, I'm a few years out of school and out of practice on my Mechanics of Materials, so please pardon the fundamental question. Are there limitations on the use of the stress transformation equations in plane stress situations? For example I find the transformation equations don't yield...

Hi, I hope someone can help, I'm trying to design a trailer which uses adjustable legs on each corner as support legs while it is is use. The legs are adjustable and have drilled holes for the position pins, and I am trying to work out what wall thickness of leg will be adequate to provide...

Both pressure and stress are defined in terms of force per unit area. Beyond that simple relationship, what might constitute a good intuitive way to distinguish these two concepts?

Forgive ne if this sounds stupid but does GR take into account angular momentum, torsion, and other effects of rotation? The stress energy tensor doeznt appear to have any terns that are meant two accommodate angular momentum abd rotational stress.

Homework Statement Homework Equations Mx=200Nm My=300Nm Mz=600Nm Normal stress caused by bending moment at A = Mc/I = (300*0.02)/((pi*0.02^4)/4)= 47.7MPa. This answer is correct. Shear stress by Torsional Moment=Tc/J Polar moment of inertia J=(pi/2)*c^4 So I...

Hi all, It seems to me that the derivation of Maxwell stress tensor is independent of the permeability of the media or the nonliterary of its B-H relation. By this I mean that we use μ0 in the equations rather than μ. Would you please confirm that?

Hi all, I have a fundamental question about ( mechanical) stress tensor. Stress tensor a 3x3 tensor whose 9 entries looks "scalars" but in figures, the stress is illustrated by nine "vectors". Does it mean the stress tensors is in fact a 3x3x3 tensor of scalars whose nonzero entries are ignored?

Homework Statement The velocity distribution for the floe of a Newtonian fluid between 2 wide parallel plates is given by the equation u=3V/2[1-(y/h)^2] where V is the mean velocity. The fluid has a viscosity of 1.915Ns/m^2. When V=0.61m/s and h=5mm, determine: A) the shearing stress acting on...

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...

The problem Why is the normal stress 75/Area and not 125/Area. They are both acting on the same axis so how do I know which one to choose? And what does (QA) mean?

Why stress tensor must be symmetric?

Homework Statement A draw bar between a tractor and trailer is made from a length of steel bar 0.08m by 0.012m rectangular cross-section. The load is transmitted by means of a 0.015 diameter pin at each end. Determine the maximum stresses in the bar and pin if the axial load is 10,000N...

I am given a rod with mass per unit length \mu , cross sectional area A, and under a tension F. I am also told that the tension F is uniform over the cross sectional area A. Find the stress energy tensor inside the rod. I know that for the stress energy tensor T^{00} gives the energy...

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...

Homework Statement Homework Equations σ=P/A σ=My/I τ=VQ/ItThe Attempt at a Solution I'm on part C, pretty sure I have A and B, so I'm using a W18x46 Beam. I have drawn shear and moment diagrams. I just want to be clear on what part C is asking... I'm assuming this point is at the end of...

So i have a stub axle shaft, I have determined maximum bending stress at several locations and the bending moments, my question is how do you calculate shear stress in a cantilevered beam? I assumed the shear would be longitudinal along the shaft. Thanks for any assistance given.

Homework Statement Dr Stewart’s Aunt Sally was constantly reminding him that he couldn’t squeeze a quart (946 ml) into a pint pot (473 ml). Annoyed by this negative attitude, he set about proving old Sally wrong. He constructed a platform, resting on a steel piston radius 1 mm, length 10 m...

I'm doing stress analysis on a circular region on this part where an o-ring seals against. There is a 7500 PSI normal force being applied on it. So you can think about it as an annular circular flat plate (like a washer) with the 7500 PSI force uniformally distributed on the surface. I want...