Questions tagged [strength]

This is to be used for topics regarding the strength of materials, the analysis of internal forces in a body and all the governing principles which considers deformation of bodies.

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The hanging of lead weights in the Cavendish experiment of 1798

I'm working to build the Cavendish experiment of 1798 according to Cavendish's own specifications. I have a question about the hanging of the 150 kg lead weights. As seen in the image, there is a ...
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What are the physics behind a TV wall mount?

As I was installing this wall mount, I began to wonder how exactly physics is at work with it. In other words, how does the design of the mount play a role in ensuring that the mount itself supports ...
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Stress in a L-shaped Beam due to Thermal Expansion

A L-shaped frame $ABC$ (right angle at $B$) consisting of beams $AB$ and $BC$ are fixed at ends $A$ and $C$ to rigid walls. Find the tensile stress at $A$ when the temperature of the frame is raised ...
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Stress on a statically indeterminate beam with nonuniform temperature distribution

The bar below has length $a$, an uniform cross-section and has both ends fixed to walls. The temperature at the left end is raised by $\Delta T_1$ and that of the right by $\Delta T_2$, where $\Delta ...
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Resources for strength calculation for an outside aluminium loft ladder and what about it becoming brittle in cold weather?

I have been thinking for years about building an outside stair / loft ladder to climb from a platform to another one, one stair higher (3 meters). However, I never studied material strength, and I don'...
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Choosing metal plate to spread point load

I have a heavy object standing on 4 legs (about 30 mm in diameter each) on a wooden floor. The object is soon going to become even more heavier and I am concerned the legs could penetrate the floor. ...
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M16 Bolted connection. Shear strength or static load carrying capacity

Can anyone please advise in quick numbers the load carrying capacity of a bolted connection? There are 2 vertical I columns with a horizontal I beam attached using 6 x M16 bolts at each end...somewhat ...
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If I am to make a block using the materials for making paper, what would its compressive strength be?

If I am to make a block using the materials for making paper, what would its compressive strength be? I am interested in not the stacked paper test, but using the same material in a block form since I ...
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Deflection of Cantilever Beam with Midpoint Spring, Integration and Superposition Methods

How can I get the deflection required below using 1) the Integration and 2) Superposition methods (two ways)? The beam $AB$ is supported by a spring $CD$, which is fixed at $C$ with constant $k$, and ...
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Screw Calculations/Math

At the risk of every woodworker in the world snickering at me, I'm curious how strong my wood joints are and want to know how much weight a table supports. I'm an aero engineer who ended up in EE, but ...
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Stress-strain Curve Interpretation

A significant barrier to my understanding of typical engineering stress vs. engineering strain curves is that for certain values of stress, there are multiple values of strain (i.e., the stress-strain ...
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Failure load of hollow tube under transverse compression

How would one analytically calculate the maximum force a tube under transverse compression can withstand? I am specifically looking for a general equation to model the yield strength of a hollow tube ...
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Design procedure used in beam design

In the design of beams, the principal stresses and absolute maximum shear stresses are not calculated. Instead, we calculate maximum bending stress using flexure formula and equate it to allowable ...
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Waterlogged multistorey apartment

I fraction invested in a real estate project several years back. Mid way through the construction, after about 12 floors, the building contractor filed for bankruptcy. An asset reconstruction company ...
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Brittle = highly stiff but not very strong

I was trying to imagine materials undergoing collisions, and thought about materials that do not deform at all. Naturally this is an idealization that does not exist in reality but, if it did, I ...
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Why von-mises criteria considers the second invariant of deviatoric stress? [closed]

Why only the second invariant is considered? What about the third invariant?
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When we replace supports distributed reaction by point reaction in thin beams, is that considered an application of Saint-Venant principle?

I read about Saint-Venant principle which is about the effect of replacing forces by equivalent forces system that effect on the same small region of a rigid body, all examples I come across are on ...
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What is the physical reasoning behind metal becoming stronger and harder if heat treated?

I was wondering that if a proper process of heat treatment (heating to a temperature above upper critical temperature, then soaking and then quenching) is applied to a metal like steel, then what ...
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Finding out the direction of the maximum shear stress in a 3d stress tensor

I came across a problem where I was asked to find out the direction of the maximum principal stress in a given stress tensor , with the help of eigen vectors I was able to construct an equation which ...
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Help with understanding bending moment diagram of a frame structure

I have an exercise where I should calculate and draw a bending moment diagram for a frame structure. The frame structure is similar to the one below, image taken from http://structx.com: I would like ...
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Mechanics: example of less mass/volume gives more strength

Lets assume we have a mechanical element from uniform material that is supposed to work in a static load conditions. Moreover lets assume there is no gravity or gravity is negligible. Are there any ...
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How do I calculate the strength of a carbon fiber tube?

I am not a mech engineer and have been struggling with this for a while, I feel like it is pretty straight forward but I'm missing something. The problem is a horizontal tube that is supported at one ...
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Server rack modifications - strong enough?

Question: Can I modify this rack and have the result still strong enough to hold the content? I have a server rack made from Steel. However it is 1980's old and doesn't quite conform to modern ...
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Calculating break point (bend) of a material

I'm trying to compare a really tough polyurethane to baltic birch plywood to see if I can use it instead (a lot of subtractive processes to the plywood, want to eliminate it) So what i'm looking for ...
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How is the assumption that stress and strain are elastic everywhere is valid for STRESS-LIFE method for fatigue life calculation?

Stress life method is generally employed for high-cycle fatigue (HCF) applications. while HCF region is approximated by $\sigma=a(N)^b$ which gives a linear graph on log-log scale, for steels it ...
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Applying forces from the inside of a bar

I was reading Schaum's Outline: Strength of Materials (fifth edition) when I came across this solved example problem from the Tension and Compression chapter: The solution was clear to me, however ...
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Calculating the diameter of screws that are on radius 160mm from axis of rotation. I need help - I don't know If I'm thinking in the right way

First of all, english is not my first language so if there are some mistakes I made - I'm sorry and I hope everything is understandable. The example I am trying to solve reads the following: The gear ...
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Manual vs Fusion360 calculation of natural frequency of beam

I'm trying to uncover the natural frequency of a mass-less beam with 2 masses attached but getting different answers from Fusion360 vs a hand calculation. L1=1m, L2=2m, m1=10kg, m2=20kg, Young's=...
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Increasing torsional-stress resistance of an Auger at its motor-shaft joint

An auger is used to move plastic balls and is rotated by a stepper motor. Due to the balls getting jammed sometimes, this induces stress on the auger at the motor-shaft junction and breaks. Images ...
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Equivalent sheet metal thickness of different alloys

I want to replace steel plates that are being used as trim tabs on a boat with 90-10 cupronickel. The main design parameter is to make sure the plate has no less flex than the part being replaced. In ...
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Filler Material

If I was to add a filler to a metallic substance, is it possible for the Young's modulus to decrease as filler content increases? Also, when a filler is added, how do the atoms change for improving ...
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How many support beams/rods needed for a firewood storage cabinet

I am building a firewood storage cabinet which should support around 100-150 kg of firewood. The cabinet is made out of wooden boards (...
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Is it possible to use Plain Cement Concrete post for fencing?

I am in need of around 700-800 posts to fence my farm in a semi-arid area in TN state, India. In my place granite posts mined from quarries are normally used. It costs around Rs 300-400 per post(6-7ft)...
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Good estimates for torque generated while turning a dial

I'm trying to design a little device which is hand-driven and which involves turning a bevel gear pair. I want a small gear pair but I don't want it to be weak. The forces involved will be small (it's ...
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Which will be stronger for securing a cantilever umbrella in a deck

I am securing a cantilever umbrella baseplate to a deck. The decking timber will be reinforced with a pine nog between the deck joists. The options that I have are to use 10mm stainless steel coach ...
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Can strength be expressed in a single value? Can flexibility?

I'm trying to communicate information about the strength and flexibility of certain materials to laymen. Are there any recognised proxies for strength and flexibility? I've tried: $$\text{Strength ...
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Best support for a granite table top?: Flat bar 316L Stainless Steel or equal box section or unequal box section

Project is outdoor granite topped table. Table legs are two isosceles trapezoids crossed together at 90 degrees, with the legs having an internal angle of 80 degrees, made from 100 x 100 x 4mm 316L ...
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Stopping force exerted on a rope. (Checking if rated strength is sufficient)

I have a 23 kg dog, and a rope lead that is rated to 50 kg. If the dog is running away at say 6 mph and I pull on the lead to decelerate and stop the dog within say half a second or say 0.5 meter what ...
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Securing aluminum angle to steel tubing without through-bolts

Overview I'm planning a rack for solar panels on the roof of a cargo trailer. I will mount the panels to a pair of 15 series 80/20 aluminum extrusion rails. I will mount the rails to the roof of the ...
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How do I calculate the strength to weight ratio of this object?

I have an object that weighs approximately 10 grams = 0.022 pounds. I know it can hold at least 45.1 pounds without breaking. It's a cube-like object so I placed many books on top of it and weighed ...
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How to measure the stiffness of a rectangular beam, and compare it to a triangular beam?

I'm an amateur at engineering, working more on musical instruments, and I'm often in confusion regarding what exactly constitutes stiffness of a beam for a load applied on it so it could resist ...
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Same E for axial and rotational stiffness?

When we solve frames, we assume that the materials are infinitely rigid in axial direction, so all deformations are due to bending. So this means, we assume infinitely rigid modulus of elasticity, E, ...
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Strong resin for fibreglass

Is there a binding material that could be reinforced with woven glass fibres cloth for tensile strength, but which offers reasonable containment against high pressure when used minimally? Ie ...
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What is the white fiber in the copper wire of headphones?

I got a pair of in-ear headphones, broke the left earphone, bought another set, broke the right earphone, and joined the leftovers of both. I found white, grey, or beige fibers near the copper of the ...
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Poisson relationship between area and length of electric wire

I was given the following formula to relate the change of area against the change of length of an electric wire with a Poisson ratio: $ {\Delta A \over A} = -2 \nu {\Delta L \over L} $ where $ \Delta ...
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What is strain/loading rate dependence/sensitivity of compressive strength of brittle materials?

What is the definition of strain/loading rate dependence/sensitivity of compressive strength of brittle materials? Is it general strain/loading or it is specific for the brittle materials?
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How to estimate the tensile strength of inch diameter steel round?

The tensile strength for 1045 TGP Precision Steel Round is said to be 91 ksi. Although, different diameters must be a factor, right? Would a 1" diameter rod be 104.5 ksi or 1045 ksi? Say I want ...
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Should I use ST or LT values for extruded rod?

In MMPDS for AA7075-73511 (extruded rod) the Table 3.7.10.0(g3) show both ST and LT values for transverse directions. For a rod with circular cross section there is really no Short and Long transverse ...
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Beam buckling criterion?

If I have an I beam which I subject to some bending load, how can I calculate when the thinner middle part of the I beam will buckle? I though I could use Euler's critical load formula here, but it's ...
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Beginners material science for handling a load

I’ve got a reasonably strong grasp of Newtonian mechanics, but as far as material science goes I don’t know which of the many material properties I need to use to solve my problem: I’m trying to mount ...
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