All Questions
Tagged with mechanical-engineering materials
273
questions
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I was solving fluctuating load problems and the word "static" confused me
Here's a snippet of the question that was asked a couple of years ago in university exam:
A cantilever beam made of cold rolled steel for which ultimate tensile strength =540 MPa and Yield tensile ...
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0
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50
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Which aluminum alloy is used in cheap commercial load cells?
I am planning to simulate a load cell in CAD and was wondering which aluminum alloy are cheap commercial load cells made of? I noticed there is no huge difference between the common aluminum alloys in ...
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1
answer
89
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Mechanical fasteners for HDPE pipe and sheet?
I need to fasten pieces of HDPE together but I’ve heard gluing HDPE is difficult.
I've bought sheets and pipes to make a feeder for a tortoise.
I will be using the sheets for covers for the pipes.
The ...
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votes
1
answer
33
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DLC wear resistance
I read that a thickness of one micrometer of DLC coating (which, if I understood correctly, shows similar properties to diamond), increases the lifespan of an item plated with it from a week to more ...
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52
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Grade C surface plate
Surface plates come in three grades: AA, A and B. The AA grade has the best flatness, while grades A and B have respectively 2 and 4 times less accuracy. Grade B is still much flatter than normal ...
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72
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Optical table without holes
Most optical tables have holes. Are there also optical tables without holes? Or do these things have a different name?
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13
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British Standard Steel BS5S82 propagation properties
I am looking for propagation data for the BS5S82 material (case hardened). I checked in MMPDS and ESDU but to no avail. does anyone know where I can find this data? Or at least similar materials in ...
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1
answer
73
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What is fracture toughness and how is it different from the strength of a material?
Strength is just the amount of force that an object can take before breaking, so what is fracture toughness?
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4
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211
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What's the difference between ductility and stiffness?
As far as I understand they both relate to the amount of deformation based on a given amount of stress.
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64
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Belt conveyor roller spring
I wanted to know if anyone could help in this area.
I want to create an inclined conveyor belt where, when a cargo box reaches the top of the conveyor belt, the rollers sequentially move down (maybe ...
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38
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How to attach plates (my design) to the stator core of the machine more efficiently and precisely?
I am working on an electrical engineering project. However, I have come across a specific mechanical engineering problem. I have attached an image to describe what I want to do. I have primarily a ...
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20
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Determine moment and shear stress door
Determine shear stress and moment of bolt:
Internal Height of Door = 198.2 cm
Internal Width of Door = 89.9 cm
Thickness Door = 3.9 cm
Weight Door = 45.76 kg or448.9 N
Elasticity = 9.8 GPa or N/mm2
...
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26
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ASTM B209 does not list Aluminium Alloy 1070
This is my first post.
We manufacture products using various grades or alloys of Aluminium sheet, one of our common alloys is 1070. In referencing the ASTM B209/209M-21a standard I do not see 1070 ...
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1
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58
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Rotation of a tube
See image... why is it that in part 1 the answer is negative but in part 2 it is added instead of subtracted?
I thought because I got a negative in part 1 I would have to subtract in part 2 but the ...
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2
answers
84
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Failing engine A-Mount (bad design by the automotive manufacturer?)
I currently own a Tata Nexon Petrol car (in India) where I have seen (on facebook, Telegram, WhatsApp owner groups and youtube) that the A-Mount on the engine has suffered multiple failures for some ...
- 101
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1
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64
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Material suited for fixing leakage in liquid nitrogen dewar
I need to fix a leak on the inside of a liquid nitrogen dewar which acts as the coolant tank for a spectroscopy CCD camera. Due to the design of the camera, I unfortunately can only access the inside ...
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42
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Tolerances in the manufacture of mechanical parts (plastic)
It is necessary to make an adapter ring for connecting the smartphone to the microscope eyepiece (turn from ABS on a lathe, or 3D printing). Microscope eyepiece diameter is 33mm.
What should be the ...
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13
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How can I calculate the maximum center load on a horizontal cellular glass tile; supported along its edges, before it breaks?
Insulating cellular glass boards or tiles are designed to sit on a flat load-bearing surface. I want to consider the situation where the base is concave so the tile is only supported on its edges. I ...
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40
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How can I reduce noise from pushrods in an assembly without using grease/oil?
I have an assembly which consists of a row of vertically-oriented nylon pushrods (each 5/16" in diameter, colored green in the attached pictures), and two black pieces of laser cut delrin ...
2
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28
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What determines the rate of electron discharge machining (EDM) for different materials?
Wire EDM makes no contact with the work piece and disregards hardness.
I am using EDM to cut different materials, and I notice a clear distinction between the rate each material gets cut. For example, ...
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1
answer
52
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Potential Problems of Excessively Hard Shaft
Will there be any issues if we make the shaft too hard?
Hardness being a surface property may prevent surface scratches and wear, could it lead to any problems in general?
- 88
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48
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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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1
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18
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Calulating the compression deformation using strain data measured by strain gauge _ material engineering
I'm studying material engineering and conducting some experiment.
The experiment was measuring the strain of long steel bar.
The bar is compressed from left side and deformed shortened.
Using strain ...
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2
answers
65
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Replicating an impact impulse
I am building a test-rig for a device. I have operational data showing the device experiences impact loads resembling a half-sine pulse with width dt and magnitude F. The test rig's purpose is to ...
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1
answer
44
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Valox 420 30% glass wear
I am seeking assistance regarding thermoplastic material wear on a new product I am developing.
The attached image is molded out of Valox 420 30% glass. In the left side image, the locking dents are ...
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1
answer
71
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What would be an ideal material to use for O-rings on a canister in a lubricant-less, high-velocity pneumatic tube system?
I am interested in building an experimental lubricant-less pneumatic tube system in which the canister will be propelled up to a high-velocity, reaching a peak velocity of approximately 100 m/s before ...
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37
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replacing the sound a small toy speaker makes
not sure if this counts for this community, and im open to suggestions where this would belong but im looking for advice.
i have no experience in working with physical hardware, as the limited ...
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1
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158
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How much force is acting on the screws I used?
Years ago I built a vertical rack to store long lengths of wood. The rack was built using 2x4" pine scrap. Imagine a typical wall assembly with a single top and bottom "plate" (2x4) ...
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1
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311
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What's the difference between amount of phase and chemical composition of the phase
I don't understand the difference between chemical composition and the amount of phase, why does the chemical composition of the phase not add up to 100%. For example in the image below the chemical ...
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1
answer
37
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How to determine the minimum thickness for a Red Dot Sight mount built in aluminum?
I'm designing what is called a "Red Dot Sight Mount" (see image below) for a handgun.
Disclaimer: this kind of part is not regulated (at least not in any country that I can think of) and ...
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28
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What is the effect of lateral friction on the specimen shape
During compression test lateral friction occurs on the lower and upper surfaces of the specimen how does this affect the final shape of it and how do we reduce this effect?
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52
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How do you plot a relation between hardness and strain
How do I plot the relation between hardness of a material and compressive strain knowing the stress-strain curve and indentation size in Brinell's hardness test
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2
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199
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How to mold a silicone sheet?
I'd like to produce prototype parts by molding a silicon sheet (0.6mm thickness) to a shape that looks roughly like below:
If split in two, this part looks like this:
I have attempted to print this ...
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1
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621
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Why does the stress strain curve sometimes not start from zero?
Here this is a Load-Displacement curve from a compression test I did earlier with my colleges, Below is the resulted stress strain curve from the test from the lab computer why did the curve not start ...
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1
answer
40
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How are surface roughness specimens created?
I'm wondering how surface roughness specimens that are used to calibrate surface roughness machines are created. Specifically those in the 125-200 µin range. Is this typically done with vertical ...
- 25
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3
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423
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Difference between elastic limit and yield stress
I am having trouble understanding the difference between elastic limit and yield stress. I searched the internet for a few hours and found some conflicting answers. I have found 3 (maybe) different ...
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1
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109
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In Column Bucking strength of 24' 3"x3" Hollow Aluminum Tube with .125" Wall thickness
I am designing a Gin Pole to lift a 500# load. The pole will be hollow Aluminum tube 24'x3"x3" and .125" wall thickness pinned at both ends. The pole will be at a 45 degree with the ...
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1
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122
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What is the best pattern of lightening holes to drill vertically (i.e. along the transverse plane) through a rod of aluminum
I have a 5' long, 2" diameter piece of aluminum round bar. I want to make it at least 30% lighter, while preserving as much rigidity as possible. (The force I'm most concerned about is torsion, ...
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2
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145
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What are the practical solutions to manufacturing this mechanical piece?
My Custom Piece (Measures are in mm)
I'm designing a custom mechanism that needs this piece to be able to function, but when i started thinking about how to manufacture it, I started getting confused ...
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3
answers
51
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Does the surface finish of the strings on a musical instrument impact the timbre?
Suppose we are testing out different unwound strings on a piano.
Each of the tested strings is made of the same material, has the same length, same diameter, density, etc., the only difference being ...
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1
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42
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Aluminium tubing strength - size/thickness v length for supporting its own weight
I want to make a simple fruit picker for a tall fig tree. Most of the fruit is lost as it drops when ripe and explodes on impact with the ground below. That or the birds get to it before we do!
So ...
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2
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90
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Is ultimate tensile strength is constant for a material?
Is ultimate tensile strength is constant for a material? I have performed a tensile test of a frame tube and I made the dumbbell for tensile test.
The test specimen (A) has a thickness 2mm while test ...
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3
answers
320
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Relation between welding bead and outer diameter of a pipe?
How can we find a relation between welding bead and outer diameter of a pipe? Welding bead is inside of the pipe and I am using M.S. pipe.
Dimensions are listed below:
Pipe OD=25.4mm
Thickness=2mm
...
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1
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176
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What would happen if we applied a stress greater than the yield stress to a rigid-perfectly plastic material?
Say we had a material that was rigid perfectly plastic, with a stress-strain characteristic as shown:
Say that we are drawing this material through two dies, something like this:
What would happen ...
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29
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Requirement : Open Source API providing properties of engineering materials [closed]
We are a bunch of four in the ultimate year of the 'Bachelor of Engineering - Mechanical' degree. Our final year project is titled 'Computer-Aided Part-Code Generator for industrial parts'.
For the ...
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3
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3k
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What is the difference between Hooke's Law and Young's Modulus?
In the elastic region where stress is proportional to strain up to elastic limit which is we call Young's Modulus (E). My question is if that is E, then what is Hooke's Law (K=F/x spring stiffness). I ...
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2
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101
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Best way to prepare a rusty metal surface for hardness testing?
I have a hardox #10mm plate that needs to be tested on Rockwell hardness.
As hardox is sensible to heat I would like to avoid any heat treatment before the testing.
The plate has been water cut.
The ...
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1
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29
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What wire rope to use for a load-bearing telescoping lift, and how to secure it
I'm trying to find a thread that has good fatigue resistance and strength for a telescoping lift to be used in a robotics competition. The lift will lift a weight of around 2-3 kg. I do not intend to ...
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2
answers
51
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Will the material plastically deform or fail when heating or cooling?
You have a stainless-steel rod with constraints on both ends that is held rigid. Initially, it is at room temperature before getting heated to 300 Celsius. Then, it is cooled to room temperature again....
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37
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mechanism design for matrix of adjustable direction pointer
I need to construct a matrix of light pointers, each one aims in specific direction, and each pointer direction will be adjusted thousands times, size is flexible could be millimeters or centimeter ...
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