1. ### FEA Hand Calculation Validation

I have ran an FEA analysis on part screenshot below. I wanted to do some hand calculations to validate the results. What formula should I use to calculate the stress?
2. ### How to calculate stress on a pipe wall

I have a PVC fitting that keeps cracking. The fitting consists of 2 parts. One piece is placed over the end of a flexible PVC ribbed hose, and the other is inserted inside the hose. The 2 parts act as a compression fitting to attach to the end of the hose. The hose typically has an outside...
3. ### How can I show that the bulk modulus is about r^-4?

Homework Statement Using the equations, show the bulk modulus is about r^-4. Homework Equations The Attempt at a Solution Tried to plug Uij but it is not same as U. To be honest, I don't know where to start.
4. ### Usage of Taylor's formula on stress analysis

Moderator Note: Thread moved from forum Atomic, Solid State, Comp. Physic, so no homework template shown. What function do they use Taylor's formula on? And can you show how they derive it? I know how one derives Taylor formula. Thanks! The text i taken from this...
5. ### I Stress as momentum flux

I'm trtying to get a better understanding of the spatial part of the energy-momentum tensor, and although similar questions have been asked here, I think the point I do not fully grasp has not been covered so far. The stress tensor can be considered as "momentum flux density" tensor. If I...
6. ### Static Equilibrium

I have a 3 pulley system statically balanced hanging weights at a determined relative angle (we are taking into account friction). If I change the position of one pulley, angles will remain the same. However, if I have a 4 pulley system, at the same conditions, changing one's position will...
7. ### I Why is stress a tensor

Before I go any further, I do understand the ways that mechanical engineering textbooks explain why stress is a tensor. But all of those explanations seem infused with geometry (which I do NOT mean in a negative way at all); and are demonsrtrations. I am searching for a more concise/abstract...
8. ### Bending stresses

Homework Statement The second moment of area of the beam shown about the neutral axis X X is 4x10^6mm^4 Find the maximum bending stresses, tensile and compressive, set up in a beam of this section 2.6m long and simply supported at its ends and carrying a concentrated load of 4.8kn at its mid...
9. ### Fatigue of a rotor

I have a fast rotating rotor spinning over 2 axis (over its main axis and over an external axis - the two axis are perpendicular to each other). Easiest to imagine this is like a windturbine yawing as it follows the wind direction. Each of the two rotations obviously causes a distinct...
10. ### B A statistical definition of Young's Modulus?

Young's Modulus is usually defined as the intrinsic property of a material indicating it's stiffness, or it's ability to resist deformation. Though, it is measured in Pa, meaning it should have some statistical description. Spring constant, for example, can be define as the stiffness of an item...
11. ### I Isn't the force calculated twice?

Isn't the force calculated twice here? For example, the force along AB is at first calculated for the resultant force along OB, then for the resultant force along AC. I think the compression and tensile stress should be ##\frac{F}{2a}##.
12. ### Stress in a rod with a hole for pin-joint

If a rod is in compression, will the minimum area on rod ( the section where there is a hole for pin) stress free? What if the rod is in tension? The rod BC is in compression and the boom AB is in tension? http://imgur.com/a/6asfB
13. ### Traction/ Compression stress and strain exercise

Hello everyone, could you help me with this exercise? I am stuck, and I can't find anything on the internet that solves this. Your help is very much appreciated :) 1. Homework Statement Circular steel bar, clamped at extremities. Two parts: A(ab)=800mm² A(bc)=400mm² L(ab)=...
14. ### What are s.g. units ??

Hi all, I am currently trying to understand a paper which presents a model for sand production and wellbore collapse in the oil&gas industry. The paper refers to stresses and pressure in "s.g." instead of Pa or other pressure/stress units... values tend to range from 0.4 s.g. for cohesive rock...
15. ### Non-uniform stress distrubution

Hi everyone! I have perhaps a basic question, but I can't dealt with it. I have a rectangular sample 50x150mm of let's say wood. The sample is compressed from the top over the width of 4mm. I know the shortening of the sample at 70 mm from the bottom (from experimental testing) and I know the...
16. ### Deriving Strain in Cantilever Beam with Known Deflection

I am trying to derive the strain at the base of a cantilever beam with a known deflection. I know the bending stress is equal to Mc/I, so the strain is Mc/IE, where c is the distance from the neutral axis. For a point load ,P, the strain would then be PL/IE. Since the deflection is known I...
17. ### Is a latex balloon's maximum strain independent of thickness?

Is latex balloon maximum strain independent of latex thickness? I have been in search of a latex balloon that is relatively small when deflated and very large when fully inflated. Standard balloons that reach the desired inflated dimensions are much larger deflated than I would like...
18. ### What will be stress in the unbalanced force situation

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > Problem Statement: Case 1: Mass is m; Cross sectional area is uniform A. What will be the stress in the middle section. Case 2: Bar is massless; What will be the stress in the middle section...
19. ### Strain of a Cantilever beam

Hi, Well i have a system with a excited (in y axis) cantilever beam. I struggling to obtain a expression that gives the strain based on the dislocation y. I know that the displacement of the beam is given by: Ya=PL^3/(3EI) but how i make a correlation between this and the strain of the...
20. ### What is the stress of the rotated axis

Given only the triaxial stresses: ax = 10 MPa (along [100]), ay = 10 MPa (along [010]), and ax = -30 MPa (along [001]), what is now the components of stresses in rotated axis? so based on the equation aT = [L][a][LT] let aT the components of stress of rotated axis, L the direction cosine, LT...
21. ### Calculating stress and strains for beam of applied force

Homework Statement If I consider a force, which is applied to both ends of a rectangular beam to its cross section with dimensions w (width) and h (height) and I know the length of the beam is l and the force is parallel, how can I calculate the stress? Also, what if the force were parallel to...
22. ### Decomposing Uniaxial Stresses

Homework Statement I am having trouble decomposing a uniaxial compressive stress into hydrostatic and pure shear components. Homework Equations The Attempt at a Solution I am starting with ## \begin{pmatrix} -\sigma & 0 & 0 \\ 0 & 0 & 0\\ 0 & 0 & 0 \end{pmatrix} ## I then do ##...
23. ### Work done up to fracture

Good day everyone! i have a problem dealing with the fracture analysis. We all know that the work done per unit volume is equal to the area under the curve of stress-strain curve or we can express it in terms of integral form, and if we're looking at necking point stress can be express in this...
24. ### Machine elements stress concentration

Homework Statement A flat part with constant thickness b is loaded in tension as shown. The height changes from 50 to 87 mm with a radius r = 4.0 mm. Find how much lower a load can be transmitted through the bar if the height increases from 50 to 100 mm and the radius increases from 4.0 to 10...
25. ### Critical Buckling loads-how to plot?

Homework Statement Hi all, I am an architect so engineering is not my strong point. for these equations I am unsure how to correctly determine the mode of failure and plot a graph. Any help would be greatly appreciated. Also the attached files have the formulas written and question written...
26. ### Resulting force using moment?

I just can't figure this out with the stresses and moments. What is the force required on the handle to get the 850N on top? Link to album: goo.gl/FYpc0k
27. ### Rotating wire tension

Hello this is my first question here :) So here is my problem: We have a circle radius 50 (m), made out of iron wire mass 5.506206591207348477884587 Kg per meter of rope. Rope diameter 11/8 inces or 3.4925cm The wire rotates with 3 rpm in zero gravity 1)How can i calculate the tension? Thx...
28. ### Graphing stress-strain plots on excel

1. I'm given time (s), extension (mm), tensile stress (mPa), and tensile strain (%) in a table. I'm supposed to graph it on excel, but my graphs don't look at all like a stress-strain graph. 2. I think it's probably because I'm using tensile stress or strain? Or is it an excel error I'm doing...
29. ### Calculating load per unit length

I am having the hardest time calculating q, the load per unit length. This question is in relation to my previous question I posted here. I have a cylinder laying horizontally that is fixed on its ends. The cylinder is filled with water. To calculate the deflection I am simplifying the problem...
30. ### Cylinder filled with water deflection study

I am having some problems understanding how to apply a distributed load to a cylinder due to it being filled with water. Attached is an image of the cylinder (placed horizontally). The cylinder is symmetric about the y axis. Water is to be filled from the left through the 1" hole. The cylinder...