Stress Definition and 1000 Threads

Homework Statement https://en.wikipedia.org/wiki/Cauchy_stress_tensor[/B] I don't understand the difference between τxy . τyx , τxz , τzx , τyz , τzy ..What did they mean ? Homework EquationsThe Attempt at a Solution taking τxy and τyx as example , what are the difference between them ? They...

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

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)=...

Homework Statement In the question , the author calculated the Ixx and Iyy , but he used the greater value (Ixx) in the calculation to calculate the shear stress , why did he do so ? why the greater value is used ? Homework EquationsThe Attempt at a Solution

Homework Statement I think the notes is wrong . in the notes , it's given that σ allowable > Mmax / Ze Homework EquationsThe Attempt at a Solution i think it should be σ allowable > Mmax < Ze , am i right ? How could the σ allowable > Mmax / Ze ? If σ allowable > Mmax / Ze , the beam will...

It is one more weekend before I get an official answer for my PhD request... I am totally broken (mentally) and stressed as I am the worst-case-scenario person... In the past, this trait of mine made me reach a point where I said "screw it, if it happens it happens"... unfortunately this time it...

http://www.efunda.com/formulae/solid_mechanics/mat_mechanics/pressure_vessel.cfmaccording to the text above, we assume that force acting on the thin wall is p*2pi*r^2 whcih is the internal area of vertical slice. But I am not sure why the area has to be 2*pi*r^2. I mean, why pressure on the...

From Carroll (2004) It is possible to derive the Einstein Equations (with ##c=1##) via functional variation of an action $$S=\dfrac{S_H}{16\pi G}+S_M$$ where $$S_H= \int \sqrt{-g}R_{\mu\nu}g^{\mu\nu}d^4 x$$ and ##S_M## is a corresponding action representing matter. We can decompose ##\delta...

Homework Statement in the formula of shear stress τ = (V)(Q) / It , Q=Ay = first moment of inertia of area, the area can be located above(or bottom) at the point of interest) when the chosen point is at the wall(boundary) , why shear stress = 0? Homework EquationsThe Attempt at a Solution When...

I have to calculate Airy's stress function for a cantilever beam made of two different material along its length. The young's modulus of the first half is E1 and E2 for second half. The beam is made such that these materials are joined to each other one after other along its length. At the...

Homework Statement https://en.wikipedia.org/wiki/Bending [/B] form the link, we know that σ represent the bending stress, I'm wondering can I call the bending stress as normal stress act at the cross sectional area of beam?Homework EquationsThe Attempt at a Solution IMO, they are not the...

I have an application where I'm trying to lift an object by using a pulley and pulling on the cable. We were forced to use a pretty small pulley and thin cable, so my question is how to analyze the total stress of the cable? I should be looking for axial stress, bending stress (cable around...

Homework Statement I know that an element that is subjected to max shear stress is 45 degree away from position of an element that is subjected to principal stress.I couldn't understand why the θ s= θ p -45 degree? Cant it be θ s= θ p +45 degree ? Homework EquationsThe Attempt at a Solution...

Homework Statement in the formula of shear stress, t is the width of member's cross sectional area calculated about neutral axis. for τc , why t is 6.4 ? Why not 102.1 ? second question, why we have to consider that specific area? Cant we consider the (red) area? Homework EquationsThe Attempt...

Homework Statement i know that to calculate the shear stress, formula is τ= (V)(Q)/ (I)(t) So, why the author choose to use Ixx, but not Iyy for shear stress at P? Homework EquationsThe Attempt at a Solution IMO, we should done the question in 2 ways, which are by using Ixx and Iyy...

Homework Statement In my book, I was told that when an element is subjected to pure shear stress, equalibrium required that equal shear stress must be developed on four sides of the element...these stresses must be direct toward or away from opposite corners of element.. Homework EquationsThe...

Homework Statement where V = total shear force at the location in question; Q = statical moment of area; t = thickness in the material perpendicular to the shear; I = Moment of Inertia of the entire cross sectional area. based on this formula , the shear stress is max at the neutral axis of...

Homework Statement in the old thread , i was told that The formula for calculating the shear stress is a beam is ##τ = \frac{V ⋅ Q}{I ⋅ t}## τ - shear stress V - shear force Q - first moment of area above the location where the shear stress is calculated. I - second moment of area for the...

Unsure how to calculate in order to get the stress (N/mm2) and strain (%) if: a material has a length of 50mm diameter of 12mm Load: 11.5 kN Extension 0.025 mm Help on how to work this out would be very appreciated :)

Homework Statement Refer to the second photo , Q= Ay Does the author mean point P is at the center of the region (62.5mm x 100mm) ?The figure is not labelled well i am confused Homework EquationsThe Attempt at a Solution In the notes , I was told that y is the location of the shear stress is...

What effect do stress hormones like cortisol and adrenaline have on the limbic system?

Hi! I am looking for a textbook that explains/describes for moving mechanical structures (such as linkage mechanism, engines, ... and not buildings, bridges, ...) the stresses, deformation, wear, temperature change, ... due to operating. E.g. Linkage mechanism: what are/defines the stresses...

The rate of working of the Reynolds Stress can be written as: where ui is the fluctuating velocity and Ūi is the time-averaged velocity. It is stated in the textbook that, if we integrate the above equation over a closed volume V, the divergence term on the left integrates to zero since τRij...

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...

Homework Statement a.)why the angle θ p is in clockwise direction? why shouldn't it be in anticlockwise direction? b.) I have labelled A,B ,C and D...Why the maximum normal stress is labelled at location A? while the min stress is labelled at location B? Can I label the min and max stress at...

Homework Statement can someone explain about part b (tensile stress) here? in which way does the stress act? Homework EquationsThe Attempt at a Solution FromW wikipedia, tensile stress refres to the stress to break a rope...How does it related to the case above?

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...

Homework Statement why the shear stress is maximum at the center ? while the normal stress is maximum at the boundary ? Homework EquationsThe Attempt at a Solution why shouldn't the shear stresss maximum at the boundary ? this is because shear stress is to pull the 2 surface apart [/B]

Homework Statement is the circled part wrong ? Homework EquationsThe Attempt at a Solution how could 0.5 sin2theta = ( 1 + cos2theta ) / 2 ?

Hi, I would like say that in this link ( ) and starting from 56.28 Suskind tries to find the energy tensor equation using \phi, afterwards he finds a equation similar to wave equation in terms of \phi. My question is: For what does \phi stand ? I could not capture the meaning of \phi. Could...

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...

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...

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >[/color] 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...

Homework Statement I want to understand why in noncicular members in torsion book tells me that surface of a member is free and so no shearing stresses there. This is from wikipedia for shafts: Note that the highest shear stress occurs on the surface of the shaft, where the radius is...

Ques: If one metal cube placed in deep sea where will be maximum shear stress in cube? What I know: In hydrostatic condition there would be no shear stress, that means on any face of cube there would be not shear stress at all. In case of two dimensional stress; if we have same...

Homework Statement The diagram represents a steel tube with wall thickness w which is small in comparison with the diameter of the tube. The tube is under tension, caused by a force T, parallel to the axis of the tube. To reduce the stress in the material of the tube, it is proposed to...

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...

Homework Statement Homework Equations Torque = Force x Distance Shear stress = Force/Area 3. The Attempt at a Solution I know how to do this question as I've seen the mark scheme. However, initially I did it wrong. What I did was as follows: Torque = Force x Distance therefore...

hello! In the question below, is the average normal force in order to calculate the average normal stress, 8sin60 or 16sin60 or 0? https://www.physicsforums.com/attachments/stress-jpg.100364/ thanks!

For a hollow tube inside a hollow tube, with a pin passing through both and a force pushing down on the innermost tube, what would the bearing stress be on the holes (assuming tube wall thickness is equal)? Would the equivalent reaction force be F/4 since the pin is passing through 4 holes? So...

Hello! I'm having some trouble understanding stress and strain rations in sheet metal forming. I understand that they're constants, but how do you calculate them? Or are they usually given? Thank you!

I understand that if you glue together two pieces of a bar together at an incline, and apply an axial tensile force (normal) to the bar, that as far as the layer of glue is concerned, the force applied to it is partly normal (normal to the surface of the glue layer) and shear (perpendicular to...

When finding the Von Mises of given a stress tensor who's only element is a single shear component (τ): \begin{bmatrix} 0 & τ & 0\\ τ & 0 & 0\\ 0 & 0 & 0 \end{bmatrix} the result is simply √3×τ. Is the Von Mises criterion not valid when considering a single component as in this example? I...

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...

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]

1. There is a valve body in which there is a butterfly plate. A shaft goes through the butterfly plate allowing it to open and close. A sleeve is inserted into the I.D. of the butterfly plate that the shaft goes through. The I.D. of the hole (butterfly plate) that the sleeve is inserted is is...

Homework Statement In a mathematics-based investigation, I am trying to estimate the stress through a voussoir (member) of an arch bridge. However, these members have non-uniform cross-sections. I don't need to know how to exactly calculate the stress in each part of the member, only the total...

The CPSC has mandated every bicycle rim have a groove to indicate the wear on the rim. I have tested wheels extensively that I built over 100000 miles. As they wear from the brake pads the side walls will bulge from fatigue. If you are paying attention you can feel the brake grab at this spot...

Hi All I am trying to validate a nylon (PA6 Guss) clamp which has a load of 166kN on a steel tube. I am only interested in validating the clamp. My analytical (MatLab-Octave) calculations give me a peak Von Misses stress of about 145MPa When comparing to FEM in ANSYS I only get about 30MPa Can...

I modeled a simple cantilever rectangular beam in Patran of (L,W,H = 100, 6, 4) with Hexa8 elements and applied a vertical shear load (upwards) of some magnitude at the free end. Ran in Nastran and plotted the vertical shear stress distribution on a cross-section in middle of length (in order...