Questions tagged [material-science]

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What is the most accurate mathematical model of a cantilever beam's bending?

I read there are multiple models for it, Plate theory, euler-bernoulli, timoshenko beam theory etc Which is the most accurate for modelling the bending of a stressed cantilever beam?
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How to use low pass filter in lock-in amplifier?

I am doing the pump-probe experiment.After the reflection of probe beam from the sample it is passed through photodiode and then to lock-in amplifier. Now I need to extract unnecessary noise from ...
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What is the best way to simulate residual moisture evaporation off of a polymer sheet in Ansys Fluent (or something similar)

I will provide more information. I am trying to simulate residual moisture evaporation off of a polymer (let's say a thin film). I tried using VOF model but I do not see an option that allows me to ...
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I search for a solid material which dissolves in water very slowly, around 1 micrometre per hour measured from the water-contact-surface

I know there are some watersolutable Polymers out there like Polyvinylalcohol, but that would dissolve to fast. Is there some material that dissolves at around 1 micrometre per hour, regardless of pH ...
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What causes an increase in the elastic modulus in polymers?

I've learned that an increase in crystallinity increases the elastic modulus for polymers, however an increase in molecular weight does not, but why? As an increase in crystallinity increases the ...
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How does evaporation impact enthalpy calculations?

For the following question, why should one calculated the heat transfer that occurs from going from 100°C to 36.6°C? As doesn't the water reach 100°C and then vaporize instead of coming back down to ...
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Why doesn't the initial internal energy matter when calculating enthalpy?

Mathematically I saw that when the initial value of the internal energy is changed when making a calculation for enthalpy using the equations: ΔH = ΔU - PΔV and ΔH = Hf - Hi, it doesn't make a ...
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Why is the donor level in a semiconductor called a "level"?

To expand on my question - Why is the donor level in a an n-type extrinsic semi-conductor called a level instead of a band? Shouldn't it be referred to as a band instead, as the "donated ...
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Why does a hole have greater energy than valence electrons?

According to the following diagram (this is for a p-type semiconductor) : The acceptor level - which is the hole, has a higher energy than the valence electrons as it is above the valence band. But ...
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Why Green Porcelain was Used for Chalkboards

This site: https://www.businessinsider.com/why-most-blackboards-are-actually-green-and-not-black-2017-11#:~:text=The%20color%20change%20came%20in,likely%20to%20survive%20the%20journey states that ...
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Do polymers undergo uniform plastic deformation?

I've learned that the yield stress of a polymer can be marked on the tip of the first curve on the stress-strain graph of a polymer undergoing a tensile strength test, like so: As the yield stress - ...
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Representing impact strength in FEA

I am performing FEA drop tests on a PP component using explicit dynamic analysis. There are two PP's I want to compare. One has a much greater Izod impact strength (ISO 180) than the other. As the ...
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Why doesn't cross sectional area impact yield stress for a given metal?

Let's say I have two cylindrical objects of the same metal (so they have the same Young's modulus), but object A has a greater diameter than object B. If both object A and object B are under a tensile ...
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What is the purpose of the woven pattern on Kevlar bullet proof jackets?

The bulletproof vest is made of kevlar fiber. The fibers are woven together. I wonder why we don't use kevlar as a sheet rather than woven fibers.
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Why don't people use sodium silicate to bind fiberglass instead of epoxy?

I tried to search for it, but I couldn't find any answer on the subject. I could only find that water glass is normally used mixed with other stuff like sand to make casting molds. In my mind it would ...
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How to calculate the spring force of a rolled piece of steel?

If you have a steel sheet and then curled it to the point of being a semi-circle with a 30 degree (pi/6) gap from completion (...
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Carbon fiber structural strength in off-road?

The question: What would be the structural strength (and thus,safety) of using carbon fiber tubes and/or aluminium knobs in off-road car construction? So, I was watching and searching for videos of ...
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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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Reactor tube material at moderately high temps (600-1000 C) with water vapor as primary constituent of flow

I work with a type of spectrometer (made by Picarro) that uses near-infrared lasers to measure the stable isotopic composition of water vapor. The samples measured are typically liquid water samples ...
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Ideal design for a long fruit plucking pole

I need to design a long (6-7m) pole for plucking fruits from tall trees. The following are the requirements: The pole material needs to be as light as possible. The pole should not be flexible ...
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Tensile testing and the difference between theoretical results and actual

I'm trying to answer a question regarding tensile testing and how the real tests may vary from theoretically. I'm thinking temperature but think I may be missing something more obvious?
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Do asperity junctions break every time a machine starts to rotate?

After reading CONTROL OF MACHINES WITH FRICTION by Brian Armstrong-Helouvry, some questions rised. The main question I ask you is: Suppose two metal surfaces in relative motion first in static ...
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What is the difference between an alloy and a metamaterial?

Metamaterials are carefully structured materials — often consisting of periodically arranged building blocks — that exhibit properties and functionalities that differ from and surpass those of their ...
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Best material to prevent stainless steel wire abrasion (polyamide coated)

I have a 1.5mm diameter wire that must be pulled against the corner of a surface. The wire is made of stainless steel and coated with polyamide. What is the ideal material to make corner of the ...
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ISO-Strain/Stress Misunderstandings

I've conducted a 3-point beam bending test on two unidirectional composite samples of different orientation to find their Youngs' modulus. I believe I understand the basic premise behind the Iso-...
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What exactly is an invariant line strain or invariant plane strain in martensitic transformations?

I have been reading about martensitic transformations and came across the terms like invariant line strain or plane strain, glissile interface, etc. I am not able to properly visualize these. Is there ...
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Suitable ranges of electrical conductivity considered for semiconductors

I'm working on a Materials Science project guided by Machine Learning, where I try to predict the physical properties (in particular electronic properties) of materials given stoichiometry. As I'm ...
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How to understand air filter collection efficiency

It's known that air filters are used to remove particulate matter, such as vehicle cabin air filter. But I am confused whether air filter can still hold dust or particulate matter when it reaches 100% ...
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For a given a molten metal (say copper), how do you determine the best material for a 3D printer flatbed? What about circuit board?

Suppose we had a 3D printer that can spew molten metal out of a 0.1mm hot nozzle and that we can control the heat at the last 5mm of the Tungsten hot nozzle's tip. I'm wondering then how would you get ...
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Size characterization

Which technique can I use to characterize the size of my particles? They would be in the range of 50 μm to 300 μm. I have verified using a microscope, but I need a technique to analyse the size ...
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What is the significance of brittle materials and why do we use them?

What is the significance of brittle materials and why do we use them? As you can see in the stress-strain curve, brittle materials have extremely low plasticity, in which cracks can initiate without ...
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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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Measuring delamination area in imageJ

I am measuring the areas of delamination in glass fibre reinforced composites using imageJ. I converted each image into an 8-bit grayscale image and then used thresh holding to show the delaminations (...
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Why do rare-earth permanent magnets need to be recycled instead of just reused?

For years, scientists and engineers have struggled to find ways to efficiently break down and recycle rare-earth materials from various devices, especially permanent magnets.... My question is: Why do ...
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How could these 2 concrete pours affect algae build up?

Here's the image: https://ibb.co/12kJCg8 First off, I live in a third world country with little standards for home building. My family's driveway ended up like this as the laborers somehow didn't ...
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What does it mean for a polymer to absorb water and how does this relate to hydrophobicity?

My materials teacher mentioned a polymer that is used for its hydrophobic properties but also can absorb water. How can a polymer do both of these things?
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What is the bulk conductivity and relative permeability of ST52 (S355)?

I need to learn the bulk conductivity and relative permeability of ST52 (S355) to make magnetic analysis in ansys maxwell.
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Plastic hardness after machining vs molding

Should there be any difference in the hardness of a plastic material that is machined vs one that is pressed from a mold? This question is in specific reference to vinyl record production where ...
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Examples of Materials with a Coefficient of Kinetic Friction Very Close to or Equal to Coefficient of Static Friction?

I'm looking for examples of frictional materials that have a coefficient of kinetic friction that is as close to equal to their coefficient of static friction as possible. What is an example of that ...
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Material selection for plunger to be compatible with pressure seal

I am designing a jig to insert a pressure seal into a cap. The jig has a cavity which the cap fits into and then is loaded with the pressure seal which needs to be inserted further using a plunger. I'...
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Is it possible to calculate the strains applied by a force on a molecule? [closed]

This question was originally in the Physics site, but the moderator believed it was better suited for this site. Hence, I am following the advice. Is it feasible to obtain the modulus of elasticity ...
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Influence of design on corrosion control

In "Ahmad. (2006). Principles of corrosion engineering and corrosion control (1st ed.). Elsevier/BH.", it is stated that to fight against metallic corrosion it is more convenient to design (...
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Fire rated EN 13501-1 B-s1/s2, d0 sheets

I'm trying to learn more about the type of sheets I can get for a project, I would of course go for polycarbonate if not for its price, currently the project with PC will cost \$600-\$700 but I'm ...
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Is there a cloth-fabric that hardens on impact?

I am researching if there is a cloth/fiber (that can be worn) that instantly hardens on impact? I am well aware of oobleck - but this is a liquid. I also know of D30, which is a material that hardens ...
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Is it possible to estimate the young's modulus of an aluminum alloy purely based off its alloy designation?

I recently had an interview where the interviewer asked what the young's modulus would be like for an alloy like 5052 versus 6061. was a bit stumped on this one, saying that 5052 might be lower ...
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Difference between fast or slow rising force on materials' breaking strength

Assume that force is applied to a material like a rope, steel cable or a beam until it tears apart. Does it make any difference for the breaking point if the force rises slowly or really fast?
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Does hitting an obstacle hard enough to break it actually reduce self harm?

Lets say that Car-A hits barrier that is fixed to immovable posts on either side of the road. The car's momentum is such that the barrier absorbs the impact and the car comes to a near instantaneous ...
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What tools are used to design and 'program' shape-memory polymers?

I've been reading about shape-memory polymers. However, it is not clear to me what tools could be used to design the ultimate shape (the shape one obtains after applying for example electricity or ...
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How does shear/viscous stress change in liquids as applied shear force is changed?

As per Newton's law of viscosity, the dynamic viscosity of a Newtonian fluid is constant (doesn't change with applied shear stress).Consider the Couette flow used to explain viscosity . Whenever we ...
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What is meant by Material Toughness being the Ability to Absorb Energy Before Fracture?

Toughness is defined as ability of material to absorb energy when deforming before fracture. Materials with high ductility and strength will have high toughness. What is meant by ability of material ...