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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10
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4answers
21k views

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 ...
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3answers
8k views

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 ...
6
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1answer
24 views

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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2answers
100 views

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 ...
5
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2answers
4k views

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 ...
5
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1answer
227 views

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, ...
5
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1answer
105 views

Would a partial space elevator work? [closed]

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 ...
4
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1answer
143 views

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.
4
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2answers
595 views

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 ...
4
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2answers
422 views

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 ...
3
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2answers
72 views

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 ...
3
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2answers
121 views

Strength of Plastic Underwater Domes with various thicknesses

I'm currently researching the strength of domes underwater and I went down the rabithole of material science. The basics of this research (or though experiment) is to bring a dome filled with air to ...
3
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1answer
174 views

Distance of Pivot from the Rear axle

I am designing an NSAM crane. I have encountered the following issue when designing the vehicle: Generally the pivot(or the point about which the NSAM crane rotates) is in the center. But from two ...
3
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2answers
150 views

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 (...
2
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4answers
105 views

Which post would be stronger?

Just a quick question for you. Well hopefully. A contractor has installed a retaining wall with colorbond fence on top. In the contract he stipulated that he would use 65mm x 65mm x 1.6mm powder ...
2
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3answers
1k views

Springback after a plastic deformation

Before the yield point, the deformation is elastic, and then it is plastic. But what happens to the elastic 'part' of strain after the load is removed? Is it retracted fully or partly, and how does ...
2
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2answers
2k views

Is strain energy the same as potential energy, or something differen?

Sorry for this stupid, basic question. But I got hung up on it. We know from Clapeyron's theorem that the strain(internal) energy of an elastically deformed body is equal to half the work $$ U=\...
2
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2answers
539 views

Fillet weld strength calculation

I have 2 plates that are fillet welded to each other. How can I determinate the max force the weld can take before it cracks? The plates are only welded on one side because the other side is not ...
2
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1answer
67 views

“The monofilament wire has a tensile strength of 18 kg” What does this mean?

I am used to strength being measured in units of stress, such as pounds per square inch, or Pascals. I am assuming what the author is trying to say is, "this filament will break when holding 18 kg," ...
2
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1answer
74 views

Strength of bolts

I was wondering if it'd be a good idea to attach a 10kg load to the end of a movable steel rod by fastening it with just one M5 bolt. Looking at Misumi's datasheet, M5 (Class 10.9) has an allowable ...
2
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1answer
93 views

Resolution of forces and state of stress at a point

Is resolution of forces similar to expressing a vector as a linear combination of some other vectors in linear algebra? Similarly, Is the state of stress at a point in 3D similar to expressing the ...
2
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1answer
626 views

Arc welder? Cheap welding device for chainmail/chainmail jewelry

I'm hoping this is the correct StackExchange for this question/request for advice. I'm looking to buy a welder to introduce me a little to welding, my main use-case right now is the hobby projects I ...
2
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1answer
53 views

Low-tech ways of assessing relative strength of a material (yield point)

I want to compare strength of a metal before and after heat treatment, to assess to effectiveness of that treatment. (See my previous question, Aluminium softened by brazing. How to harden?). ...
2
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0answers
14 views

Is inverse hall-petch relation valid crystals larger than nanocrystalline?

The image shown here is of ceramics, where they varied the grain size and measured the strength. For example, let's take Al2O3. There we observed that strength first increased from 3 μm to 95 μm. But ...
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0answers
87 views

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 ...
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0answers
11 views

How do I relate Grab Strength and Grab Tear to the real world?

I'm looking at a spec sheet for a high density polyethylene woven fabric and I'm seeing the following parameters on it Tensile Grab Strength: Warp 155 / Weft 170 - tested ASTM D-5034-09 Grab Tear:...
2
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2answers
62 views

How to strengthen existing masonry vaults and domes? [closed]

I would like to know what methods are usually used to strengthen existing masonry vaults and domes, especially the ones called Catalan Vaults, and how to design them. Thank you in advance.
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3answers
96 views

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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1answer
262 views

Definitions of strength?

Can tensile strength be the same as yield strength? Can Flexural Yield Strength be related to the yield strength of a material in any way?
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1answer
50 views

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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1answer
268 views

With which parameter can you specify whether a metal is ductile or brittle

I have to do a durability approval of feather key (shaft-hub connection) and the formulas are dependent if the shaft respectively the hub is ductile or brittle. But what is the decision about to say ...
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3answers
35 views

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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2answers
44 views

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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1answer
39 views

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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1answer
83 views

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 ...
1
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1answer
81 views

Boron Carbide Shattering a Bullet

Does anyone know how this works? I hypothesize that the reason that the bullet shatters is that boron carbide is much harder than the copper of the bullet. Does anyone think that this may be made into ...
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1answer
866 views

What causes shear force?

Most of resources I've been reading don't explain the scientific reason for the existence of shear force. Most resources just teaches how to solve problems and about properties. Nothing goes deep (not ...
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1answer
30 views

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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1answer
46 views

Stability of 3D-printed mask after sterilisation

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6797553/ https://www.hatchbox3d.com/collections/pla We are 3D printing masks that need to be used by medical staff treating COVID19 patients. The first ...
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1answer
30 views

Is there any way to improve the strength of simple at-home aluminum/copper/brass castings (sand-casting hammers)

I'm just getting-into melting-down cans to make aluminum-based slingshots, hammers and the like. In my ignorance I didn't realize that copper/brass were also things that I could process which has ...
1
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1answer
62 views

Mounting outdoors camera using aluminum 5052

I designed a simple U shape 2mm sheet metal bent mount for a 4kg outdoors CCTV camera. The mount was accidentally produced from 5052-H32 Aluminum instead of 6061-T6. Is it common to use 5052 ...
1
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1answer
202 views

Locations of max stresses in a circular beam?

If a torque and axial force is applied to a beam with a circular cross section, where along the cross section of the circular beam is the location of the max shear stress, max bending moment, max ...
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1answer
118 views

Most efficient fillet design given an envelope (for stress)

If one has a specified allowed X length and Y height, into which a fillet can be placed to reduce stress concentrations, is there an equation which can be used to determine the optimal shape of the ...
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3answers
73 views

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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3answers
65 views

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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0answers
16 views

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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0answers
90 views

Analysis Of Planar Frame Using Hardy Cross Method (Moment Distribution) With Sway

The image shown below is a sketch of the structure/frame that I am attempting to analyse using the Hardy Cross (Moment Distribution) Method. I need to find the bending moments, axial forces and shear ...
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0answers
20 views

Generating random samples for some concrete structural characteristics [closed]

I want to test a program that performs FRP concrete structural strengthening calculations according to a particular design code. As inputs for these calculation, there is existing concrete cross ...
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0answers
25 views

Force applied on board from bed of nails [closed]

For testing a new manufacturing process of PCBs in our company, we design 2 bed of nails. One bed will have about 80 nails while the other about 180. Both beds will use the same fixture that will ...
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0answers
391 views

Will drilling a hole in a pane of glass reduce it's structural integrity?

I've got a glass box that measures 900mm x 450mm x 450mm. The width of the glass is 6mm thick. If I drill, cut, or grind a small hole in/through one of the faces; will it significantly affect the ...