Engineering Stack Exchange
Engineering Stack Exchange

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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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 happens within the metal itself on microscopic level…
Rameez Ul Haq
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Why does the stress-strain curve decrease?

This is a stress-strain diagram I have noticed that the curve decreases between points C & D and between E & F. Why does that happen? I expected the curve to always increase since the tension force in a tensile test is always increasing and the…
Eman.suradi
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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?
Sina M
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How does the strength of a square tube depend on the side size?

There are two square tubes of the same length, material and wall thickness, one being 40x40mm, the other 20x20mm. How does their strength against bending compare? On the one hand, the cross-sectional area of the 40mm tube is 4 times bigger. On the…
Greendrake
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Could a vacuum tank ever be light enough to be boyant in air?

Given futuristic materials, could a structure ever be strong enough to contain a vacuum, yet light enough to provide buoyancy under standard atmospheric pressure? Obviously "futuristic materials" is highly ambiguous because we don't know what exists…
Lorry Laurence mcLarry
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Calculating shaft diameter

I'm designing a circular shaft that's going to carry a spread radial load of about 200kg and also transmit a 160Nm torque. I'm not very familiar with materials but what I'm guessing I'll be able to get at a reasonable price locally is some lower…
php_nub_qq
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Would a partial space elevator work?

Background The normal space elevator (that reaches from the Earth's surface to a counterweight beyond geostationary) needs a material that's strength/weight ratio is better than any material we have available. I've another idea, that I assume isn't…
lionfish
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Can concrete lose strength during curing?

We cast a bridge's concrete deck and kept samples for concrete strength tests at 7 and 28 days. We took a test at 7 days, and the test result were over the design strength (designed for 30 MPa, result was 33 MPa). The control engineer insisted that…
Murat Dal
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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 below describe the issue…
Amol Patravali
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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 unclear to me how exactly I calculate the…
Beacon of Wierd
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How to provide lateral support for adjacent masonry during installation of steel UC in an old cavity wall?

I've got a structural engineer ready to provide calcs on this job, but there is a specific aspect where I'd like a heads-up what the normal approach would be, before I raise it with him, in case he says it's a matter for builders to decide (which it…
Stilez
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How to determine tensile strength while the normalised tensile strength is known?

I try to design a shaft with yet unknown diameter, i know the distribution of forces and stresses (shear, torsion and normal) in/ along the shaft. I need just one more parameter nl. the tensile strength of martial. I use Rolloff-Matek machine…
user14407
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Column Buckling Boundary Conditions -- Welded Tubing Practical Application?

I'm trying to do some calculations for a personal project. I'm trying to understand column strength / buckling. My questions relate to Effective Length Constant, which is based on Boundary Conditions (how the ends of the column are restrained) The…
zipzit
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How to compute core stress in honeycomb structure?

Assume I have a honecomb(sandwich) panel under distributed normal load. Each edge of this panel is simply supported(pinned) as on the picture below: The problem is how to find the core stresses σ-z (not on sides of the panel) as on the picture…
Eugene
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What methods are there to test the flexural, tensile and compressive strength of concrete?

The only one I know is the three point bending test for flexural strength.
opaque_dragon
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