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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Superposition of cylinder stress and normal stress
I need to calculate the principal stresses for the given cylinder with thick walls inside filled with gas shown on this picture:
I used the Lamé equations, namely:
$$\sigma_{x} = p\cdot\frac{r_{1}^2}{...
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Predicting breaking force of beam per length based on one testing
I've made a plywood carbon sheet and tested its breaking force, for a 200mm long, 50mm wide, 16mm thick it was 100kg +-
I was wondering if it's enough to help me predict what will be the breaking ...
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Angle of twist at D where 2 shaft connected through gears
So my frind and I find the answer for part A different also chegg says something else. But I can't see whats wrong with my answer. Dont expect you to solve it just show me whats wrong with my answer. ...
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How can a material be good at damping, yet also be strong?
Good Damping
Carbon bicycle frames have the unusual property that they are superior to aluminum frames in high-frequency absorption. A cyclist on a carbon-frame bike will feel tarmac chatter far less ...
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Why are the water tank walls made of stretch film warping a lot whereas theoretically they shouldn't that much?
I am building a water tank of custom dimensions (1.5 m x 0.72 m x 0.86 m) out of stretch film. The stretch film is wrapped around a steel frame (see here for more info on this open source project).
I ...
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Limit for the face width dimension of spur gears
As part of a class project, I need to design a gearbox for power transmission in a small aircraft consisting of spur gears with several constraints. There are relatively few parameters that I can ...
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Why the size of top and bottom rollers is different in three point bend test?
In a short beam shear testing of polymers, the configuration is such that the top (loading) roller is bigger than the bottom (support) rollers. Why is this the case, and what happens when the size of ...
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What does cycle mean in fatigue strength diagram?
A shaft at an usual factory might rotate 2000-3000 (10^3-10^4) per day. So, its rotation cycle easily reaches numbers indicated on X axis below. What does number of cycles in the diagram below exactly ...
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Is the a similar method of calculating moment in inelastic bending like in the case of torque for inelastic torsion?
When calculating for Torque in torsion or for Moment in the case of bending, the concept is usually first introduced with the simplification of the assumption that the stresses and strains are in the ...
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How do I calculate the strength to weight ratio of a material
I want to manufacture something using metal 3d printing. And I'm now choosing the material. Stainless steel is stronger but much heavier than aluminum, so I want to calculate which material can ...
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Spherical metal ball contains high pressure superheated steam. If we allow it to cool in atmospheric air, at what pressure steel ball will implode?
Theoretically, I know that steam will start cooling slowly at constant volume to attain thermal equilibrium as per zeroth law of thermodynamics. After some time, steam will condense to water creating ...
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Resultant Forces in a vertical rod
This is a pretty basic question. So in the below figure is the representation of prismatic column. The forces are represented as P1 and P2. let x be an arbitrary cross section between A and B. The ...
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Could electromagnets ever compete with the power of an antimatter annihilation engine? [closed]
So to make this easier to read, I've been using a few terms I'll explain really quick
"MPP": (maximum physical potential)
"MASS": (maximum atomic structure strength)
According to ...
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Why are these food stretch films (LLDPE) holding one one-thousandth of the weight in reality than what is expected from the datasheet values?
I am trying to reproduce analytically the results found in this experiment where a weight of 3 x 5 lbs (6,8 kgs total) breaks the cling wrap (LLDPE) which is stretched over a medium size cooking pot.
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Strain As A Function of Deflection of a Hollow Cylinder
I should think that there would be a direct correlation of strain to deflection of a hollow thin-walled cylinder, but I've seen nothing as of yet. I must be missing something. For example, let's say I ...
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How to analyze strongest (honeycomb?) structure?
To be specific I have a structure consisting of a solid material (eg PLA) consisting of a top horizontal slab (eg 3 cm x 3 cm x 0.5 cm) and a bottom horizontal slab (translated vertically, of the same ...
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Torsional rigidity of a composite shaft in parallel
Consider the following composite shaft which consists of 3 different materials with modulus of rigidity of $G_1$, $G_2$ and $G_3$. Shaft 1 has length 2L, and shafts 2 and 3, L. Assume they are all '...
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Timber strength in tangential and radial directions
Normally for structural timber, two values for compressive and tension strength are given. One value is given for timber in direction of the grain, and other is given at 90 degrees (perpendicular) to ...
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Calculating the theoretical strength of an FCC crystal?
I have information regarding the interplaner and interatomic spacing and shear modulus. The way I know to solve it is just dividing the shear modulus by 2π. But I'm not sure since there is the extra ...
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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 ...
