Stress Definition and 1000 Threads

Homework Statement The bottom surface (8 cm x 12 cm) of a rectangular block of cheese (3 cm thick) is clamped in a cheese grater. The grating mechanism moving across the top surface of the cheese, applies a lateral force of 20 N. The shear modulus, G, of the cheese is 3.7 kPa. Assuming the...

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...

Problem attached. I would appreciate anyone's help. I am an alloy chemist working on an MS degree in materials engineering and have come to the mechanical engineering part of the program and am feeling a bit behind. Deriving an equation for this case is proving to be difficult for me although...

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...

Homework Statement A load P of 3kN is applied to the tensile member shown and is carried at the joint by a single rivet. The angle of the shear joint is 45 degrees to the axis of the load. Calculate the tensile and shear stresses in a 10mm diameter rivet Homework EquationsThe Attempt at a...

Homework Statement The component shown in Fig 1 is made from a material with the following properties and is subjected to a compressive force of 5kN. Material Properties : Young’s Modulus of Elasticity – 200 GNm-2 Modulus of Rigidity – 90 GNm-2 Poisons ratio – 0.32 Calculate : (a) The stress in...

Homework Statement Homework Equations Equation of Equilibrium (Horizontal and Vertical Forces, Moments) Normal Stress = F/A The Attempt at a Solution I have already solved the solution for this problem. For part (a), I simply found the force in the link, and used the cross area where the...

Homework Statement In this problem , why the author use (30x10^3) /s = VQ / I only ? Shouldnt it be 4(30x10^3) /s = VQ / I Homework EquationsThe Attempt at a Solution I said so , because the board at the centered is connected by 4 bolts , 2 on the left and 2 on the right . The faces on the...

Homework Statement Homework Equations All Equations Below The Attempt at a Solution [/B]

Homework Statement For QB , why shouldn't the QB = red part only ? Homework EquationsThe Attempt at a Solution Is there anything wrong with the solution given ? Since When we 'cut ' the boards , the b is the red part which in contact with the other board , right ? [/B]

I am learning about shearing stress, and I am a little confused about the area of projection mentioned in my book. When it introduces it, it shows a plate with a rivet through it. The plate is of thickness t, and the diameter of the rivet, d. It shows the plate and the rivet cut in half by a...

Understanding Absolute Viscosity - shearing stress Hi everyone, I have found information about Absolute viscosity: Coefficient of absolute viscosity is a measure of internal resistance. Dynamic (absolute) viscosity is the tangential force per unit area required to move one horizontal plane...

Homework Statement We all know that $$\tau = VQ/ It $$ how to determine the shear stress at **G** ? I'm having problem of finding Ay centroid if the solid that i found earlier is y = 98.5mm There's a dashed line from G to the bottom . It's making me confused . for Q , should i consider the...

Homework Statement why the mean area enclosed within the boundary of the centerline of tube thickness is (0.035)(0.057) ? Is it wrong ? Second question , why for the ds it's 2(57) and 2(35) respctively ? what is ds actually ? Homework EquationsThe Attempt at a Solution for the first...

The Cauchy stress tensor at a material point is usually visualized using an infinitesimal cube. The stress vectors (traction vectors) on opposite sides of the cube are equal in magnitude and opposite in direction. As a result, the infinitesimal cube is in equilibrium. However, when we derive...

Hi Forum, I´m happy I found this forum... I hope someone can answer my (simple) question: According to this thread https://www.physicsforums.com/threads/calculating-0-2-proof-stress-of-aluminium.206648/ on page 2 the stress/strain diagram is not the same as force/elongation. Due to the constant...

Homework Statement I'm having problem with the angle of $$theta_s1$$ . My ans is +35 (as in my working) , but the ans provided is $$theta_s1$$ = -55[/B] Homework EquationsThe Attempt at a Solution As in the picture posted

Homework Statement I am not sure how to get the maximum shear force in mohr's circle [/B] Homework EquationsThe Attempt at a Solution To get the ##\theta_s max ## , we have to 'turn' the B to ##\tau_{max}## , right ? So , it should be like this ( in the figure , orange arrow) ? Am i right ...

Homework Statement [/B] For part b , i think one of the angle either $$\theta_s$$ or $$\theta_p$$ is wrong For the second question , what is plane stress ? Homework EquationsThe Attempt at a Solution [/B] 1.) Because in mohr's circle, the maximum shear stress on the vertical axis , for the...

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...

Homework Statement i'm not sure how to calculate the shear stress at point F and point G . I know that shear stress has formula of $$ \tau = VQ/It $$ The maximum shear force that i calculated earlier is V = 205kN , Ixx = 2.1x10^-4 for Q at $$\tau$$ at F , i have...

Homework Statement From the solution , it's clear that the top part of the beam undergo tension , while the lower part undergo compression . Homework EquationsThe Attempt at a Solution But , i don't understand why it is so . When the moment is applied in the horizontal axis , the structure...

Homework Statement In Euler's theory , it's stated that the critical stress of beam is always larger than the yield stress of beam ...I don't really undertstand the differnce between them . Critical stress is defined as the stress that the mximum stress applied before the beam starts to...

Homework Statement In the notes , i noticed that the shear stress on the top plane and the front plane will 'meet together' at the edge . I don't understand it why the direction is like that . Homework EquationsThe Attempt at a Solution Is it possible for both the shear stress to become like...

Homework Statement In the notes , I don't understand why the shear stress is maximum at the edge ( circle part) . Homework EquationsThe Attempt at a Solution I think it's wrong . Refer to another diagram attached , i found that the shear stress varies parabolically across the vertical length...

Homework Statement In the notes, the author stated that the shear stress is constant over the bottom face of the segment ... why in figure 7-4 , we can see that the shear stress varies ? Homework EquationsThe Attempt at a Solution Which is correct ? The red circled part or the figure ? [/B]

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 centripetal...

Homework Statement I have designed a bracket and am interested in stress at a certain point. I have figured out the load needed to support. The area of interest carries an eccentric load so bending moment and axial load need to be figured out. Not sure which FBD is correct to use. Homework...

If the von mises stress well is below the yield stress, am I right to assure the material is behaving elastically?

Homework Statement In this notes , i don't understand how the Q=(Ay) of the is considered ... Homework EquationsThe Attempt at a Solution I think the both Q at part C and part B should be = (60)(15)(mm^2) ... i have redrawn the structure , i am not sure whether it is correct or not... From...

I have a v-band clamp and I'm wanting to know the stresses for such a section. I'm interested in the forces and resultant stresses on the clamp from the flange and plug (inside the v band) opposing each other as pressure is increased. I thought of treating the section as an effective channel...

[ Mod Note: moving this to Physics H/W ] Homework Statement for this question , I'm having problem with the shear stress at point E and shear stress at centorid. normally , the shear stress at the centoid will be maximum . But , in my working , I found that the shear stress at the centroid is...

Homework Statement In the example , I suspect the selected A (area) is wrong... From the notes , A' is the area of top (or bottom ) portion of the member cross sectional area . But , in the example , we could see that the selected area is located to the right of the point where shear stress is...

Homework Statement In this notes , why the shear force used is the 19.5kN ? Why not 6.5kN ? From what i know , the formula of shear stress is tau = VQ/ It , where V is the shear force ... There are two values of V in this question , why the larger one (19.5kN ) is chosen ?Homework EquationsThe...

Homework Statement Hello, I am supposed to show that the quantity TR=JTF-t satisfies TR=∂W/∂F for some scalar function W(X, F, θ) in my continuum mechanics homework. The task is to identify this scalar function W(X, F, θ).Homework Equations This is part b) of a question. In part a), we get...

How would one go about setting up the stress energy tensor for a particle, say an electron subjected to electric an electric field that makes the particle oscillate with frequency \omega?

Homework Statement In the first photo , i was told that the I represent the moment of inertia about the neutral axis ... But , in the 2nd photo , i found that the author calculate the moment of inertia about the x-axis (parallel to neutral axis ) and y -axis ( perpendicular to neutral axis) ...

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...

Hello, I came to know that a normal component of the viscous stress can exist at a solid surface for unsteady, compressible flows(though even in that case, the normal component of the viscous stress is typically much smaller than the tangential component). I tried googling it myself but could...

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}##.

Hello everyone, I came across this in J. Anderson's book "Fundamentals of Aerodynamics". "For the type of gases and liquids of interest in aerodynamic applications, the value of the shear stress at a point on a streamline is proportional to the spatial rate of change of velocity normal to the...

Homework Statement When an element of material is subjected to pure shear stress , equlibrium requires that equal shear stress must be developed on four faces of an element . Homework EquationsThe Attempt at a Solution I can't understand the statement . I assume the 'element ' is cubic ...

Homework Statement In my book , the author stated that working stress is the maximum stress premitted under design load . Whereas the allowable stress is given by below ( refer to the notes attached ) http://imgur.com/a/YnimQ Homework EquationsThe Attempt at a Solution So , the working stress...

Homework Statement here's the question , Part of solution was given , but not the final ans . I have tried to do , but i need someone to verify my ans . Homework EquationsThe Attempt at a Solution Since , stress of steel is 12.5 times of stress of concrete . The max allowable stress in steel...

Hi guys, I'm trying to work out the following: Assume uniform shear stress distribution across "Key" width. What is the shear stress (psi) on the "Key" at the interface with the "Shaft"? Torque (in-lb) = 4959 Shaft diameter (in) = 2 Key width/height (in) = 0.3 Key length (in) = 2

Hi, I'm trying to calculate bending stress for a cylindrical beam. I'd like to have my result double checked because I got an answer that doesn't make sense to me. All of this is personal research, so I'm not very confident in my answer. It's a cantilever beam with a point mass of 347.4 oz. on...

Homework Statement For σBC end , i don't understand how the author get (20mm)(40mm-25mm) = 300x10^-6 (m^2) ... Homework EquationsThe Attempt at a Solution IMO, , the area should be the circled part (thin rectangular part of the rod) , but i only know one dimension only , which is 40mm , i don't...

Homework Statement http://holland.pk/uptow/i4/4af070d190cc175e6ca5d326cd60cda2.png The attempt at a solution the question have a possible solution? that equation is based on stress is constant, so how to use this equation to proof? i m a year 2 student. i can only solve part i...

Homework Statement my notes gave that in a 3d cubic , plane stress is state of stress in which two surfaces are free of stress ... Homework EquationsThe Attempt at a Solution Does it mean the we only consider the stresses in xy plane only ? because the object is too thin, so we assume it's 2...

If a large cloud of dust of constant ρ is moving with a given ##\vec v ## in some frame, then at any given time and position inside the cloud there should not be no net energy or i-momentum flow on any surface of constant ##x^i ## (i=1,2,3) because the particles coming in cancels those going out...