14

In short the heat treatments in steel change the phase of iron between the following phases: Austenite Cementite Martensite Bainite Ferrite Perlite. (Actually quenching does not allow low temperature phase changes to occur, so effectively the phases are sort of "frozen" in their high temperature equivalents). Figure 1 : example of continuoous ...


9

The effects of heating-quenching a metal is explained below Transformation hardening is the heat-quench-tempering heat treatment cycle addressed earlier in this article. It's used to adjust strength and ductility to meet specific application requirements. There are three steps to transformation hardening: Cause the steel to become completely austenitic by ...


7

You could try a bath of concentrated acid. As long as you could maintain circulation so the concentration was fairly constant, a spring presents a very uniform cross-section and should be dissolved at a consistent rate. I would recommend keeping one of the springs as a reference so that you can measure the result after a short period and adjust your time ...


6

If we're staying within the realms of beam theory, we can go with this approach which is valid for any material that exhibits linear-elastic behaviour before yield: The curvature of a beam is related to the applied moment and it's flexural stiffness: $$ \begin{align} \kappa = \frac{M}{EI} \end{align} $$ where, for a cicular rod, $I = \frac{\pi d^4}{64}$. ...


6

You are mixing apples and oranges. Many steels harden by rapid cooling, but very few other metals do that; specifically, only aluminum bronze and certain titanium alloys. Many metals will strengthen by age hardening; Rapid cool softens, and then time at a lower temperature strengthens them. There are a myriad of combinations, like HSS (high-speed steels). ...


5

You are asking for an unrealistic material. If you peruse the engineering toolbox you'll find that the Young's modulus of typical materials is measured in 109 Pa so the value you are asking for is 7 orders of magnitude smaller than typical materials. Even the Young's modulus of the rubber in rubber bands is ~107 Pa. Another simple thought experiment will ...


4

A simple first order approach would be to treat the plate like a composite material, with the holes acting as a medium with no modulus. The rule of mixtures , treating the "holes" as fibers with 0 modulus, would yield a modulus of 0. So, the Semi-Emperical Halpin Tsai would be better: $$ \eta = \frac{\frac{E_f}{E_m} -1}{\frac{E_f}{E_m}+1} $$ $$ E_c = \...


4

This has been asked and answered numerous times before: https://www.quora.com/Why-is-strain-energy-equal-to-1-2*force*displacement-What-about-the-remaining-half basically, it's because you're calculating the area under a triangle, because the strain energy increases linearly as the displacement increases. The Work term here refers to the final position, but ...


4

By "strength" do you mean stiffness/modulus? The modulus does not change with tensile or yield strengths. Make it with wire of 1/2 the diameter for 1/2 the modulus. Acid will hydrogen stress crack hardened steel ( This condition has many other names like "embrittlement".). Make it out of aluminum and get 1/3 the modulus or titanium and get 2/3 the modulus ( ...


4

TL;DR: Yes, any structure deforms if you put a load on it. Even adding an ant on top of a granite mountain will change (lower) the height of the mountain - imperceptibly so but it will still change it. The problem is that its not possible to measure it. That is the whole idea behind Young's Modulus (modulus of elasticity). Essentially, all materials behave ...


4

If I understood correctly you are only after the stress-strain curves. Figure: Stress strain curves for different types of materials (source What's pipping) Perfectly Elastic : (referred to as Linear Elastic) returns to its original shape, and the force is proportional to the deformation (definition may vary) Perfectly plastic : (referred to in the image ...


4

The other answers describe the "materials science" mechanisms of iron vs. temperature. I'm going to add this: Matter "tries" to reach a minimum energy state whenever possible. In general, then, if you cool something as slowly as possible, you'll come closest to a solid which is a perfect crystalline structure. See "annealing."...


3

Material science can almost always be broken down into "generally useful" and "specifically useful". The link in the comments demonstrates a commonly used statistic that describes behavior of foams at higher strain values - the three dimensional strain energy density function. But this statistic is "generally useful". It generalizes to all foams. In ...


3

The elastic modulus would give you how much it would twist in use, you would need the tensile strength: taken from engineering toolbox http://www.engineeringtoolbox.com/torsion-shafts-d_947.html : τ = T r / J (1) where τ = shear stress (Pa, psi) T = twisting moment (Nm, in lb) r = distance from center to stressed surface in ...


3

Definitions Before we can answer your question, let us look at two standard definitions of terms (from ASME Guide for Verification and Validation in Computational Solid Mechanics) : 1) Verification: The process of determining that a computational model accurately represents the underlying mathematical model and its solution. 2) Validation: The process ...


3

The answer to this lies in the defining equation for the strains that you have supplied. The full displacement gradient $u_{i,j}$ (where the $\bullet_{,j}$ represents the $j^{\rm th}$ derivative) can be linearly decomposed into a symmetric and an anti-symmetric component: $u_{i,j} = \epsilon_{i,j} + \omega_{i,j}$, in the usual way as for all rank-2 tensors. ...


3

For concrete and asphalt, you would be more interested in the properties of creep, which is always a function of temperature. For example, there is an entire wikipedia page about this at this time, which mainly references ACI Committee 209 For polymers, there are many models for creep. Due to the extensive range of polymer chains, it would be difficult to ...


3

The fundamental beam equation is $$\dfrac{\text{d}^2}{\text{d}x^2}\left(EI\dfrac{\text{d}^2w}{\text{d}x^2}\right) = q$$ Which basically translates to "the fourth derivative of the deflection function is equal to the applied load". In fact the first derivative is the tangent of the deflection, which for small angles is approximately equal to the angle of ...


3

Probably just another hypotetical idea: If you squeeze the wire from circular into a square shape, it will have about 54% of the original rate. If you squeeze it slightly more into a rectangle, it will at some point become 50%. And 1/2 the diameter of the wire does not gie you 1/2 the rate. It would give you 1/16 of the rate. 85% of the diameter gives you ...


3

Another hypothetical way to reduce the amount of material in the spring would be to fix it in a jig stretched to double its normal length. Then, heat it sufficiently to anneal it and remove the tension in it. Then, re-temper it and cut it in half, back to its original length. But just buying a new spring would be a much simpler method.


3

It hasn't disappeared. You have made your hand a little warmer because your own tissue has deformed. Your hand will return to its original shape and the generated heat will be moved to the environment as radiation and by convection. If you tried too hard you could see and remember the consequences at least a while. The concrete generally happens to be much ...


3

For small strains of stable materials, the tensile and compressive elastic moduli are equal. This is equivalent to saying that a smooth energy minimum looks like a (symmetric) parabola up close; an energy well in the shape of a parabola characterizes an ideal spring with equal elongation and contraction spring constants. This approximation works well for ...


3

Anelastic is a material that exhibits a delay in the deformation with respect to the loading. figure 1: Anelastic material bevahiour (left: wrt to time, right: stress vs. strain) (source Princeton) Visco-elastic are materials that the load to obtain the deformation also depends on the strain rate. I.e. How fast the deformation is applied. It might depend on ...


2

'I' doesn't change for the different situations. 'I' is a property of the cross-section of the beam - a rectangle of width w and depth h. The Eb equations are correct for the situations set out, with the following caveats: The first situation is not for a beam that is fixed at both ends, it is for a beam that is supported at both ends but not 'fixed'. '...


2

This is quite a poorly-worded question. After all, how do the layers interact with one another? Can they be considered to be fully bonded to one another? I assume not, because then they've behave as one element, which kind of beats the purpose. Should we assume that the load is evenly distributed between each of the layers (so, for a given load $q$, if you ...


2

The modulus of elasticity is not going to significantly change for concrete in ambient temperatures but there are provisos. The assumption is that you are talking about set concrete that has achieved 28 day strength. If you are talking about fluid concrete then that is down to the slump test and results are highly variable between strength types. High ...


2

all tensile testers exhibit this accomodation range to a slight degree, but in your case the large accomodation range is most likely caused by worn parts in the drive mechanism that pulls on the bar- most likely the mechanical "grabbers" that dig into and engage the ends of the bar under test. this might be the reason that this machine was discarded in the ...


2

The hyperelastic and viscoelastic material models are both constitutive relations that relate: Stress and strain, in the case of hyperelasticity. Stress, strain and strain rate, in the case of viscoelasticity. They are both empirical models, which means that you typically need to run experiments to find the necessary parameters to fit each model (there are ...


2

Let's look at some (very rough) definitions: 1) Viscoelasticity = elastic behavior that changes if the rate of application of the load is changed or, if the load is kept fixed, the change in the elastic behavior of a material over time. 2) Hyperelasticity = rate/time-independent elastic behavior beyond linear elasticity Of course, elastic behavior means ...


2

Rather than thinking about a Young's modulus directly, the problem becomes easier to grasp if you think in terms of a relationship between the load and displacement, and subsequently between stress and the strain. If you consider the case where deformations are small, and just consider the stiff direction (tension/compression vertically and not horizontal ...


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