automotive engineering - What is the significance of brittle …
2022年4月6日 · As you can see in the stress-strain curve, brittle materials have extremely low plasticity, in which cracks can initiate without plastic deformation and can soon evolve into brittle breakage. We have studied that cast iron which is a brittle material is used in automobile cylinder block, head, housing flywheel etc.
materials - Brittle = highly stiff but not very strong - Engineering ...
2021年11月7日 · I think "stiff is a better word to describe a "strong" but brittle material. The design of the modern car is well balanced in between flexibility and rigidity, so it can dampen the impact force during a collision, but not deform to an extent that causes excess body harm and threaten the life of the riders. $\endgroup$
Failure in torsion - Engineering Stack Exchange
2017年8月16日 · For brittle materials on the other hand, Maximum-Normal-Stress Theory says: [...] a brittle material will fail when the maximum tensile stress, $\sigma_1$, in the material reaches a value that is equal to the ultimate normal stress the material can sustain […] – R.C. Hibbeler, Mechanics of Materials, p.528
Why ductile materials fail in shear when subjected to torsion?
I was reading the book Mechanics of Materials by Beer and Johnston.The author points out in torsion chapter that ductile materials generally fail in shear.And brittle materials materials are weaker in tension than in shear.From this they concluded that when subjected to torsion a circular shaft made of ductile material breaks along a plane ...
stresses - Shouldn't brittle materials be the ones failing under …
2019年6月20日 · Brittle materials often are bound together into crystals by ionic bonds between atoms, with alternating positive and negative charged atoms. I remember also that brittle materials fail when ionic bonds between layers are broken and the layers shift, causing like-charges to move close and therefore repel each other.
Hardening and Brittleness - Engineering Stack Exchange
2018年2月22日 · Brittleness describes the inability of a material to absorb a considerable amount of plastic deformation. Thus, the material fails without a lot of deformation. Hardening, on the other hand is the process of increasing a material's yield strength $\sigma_y$ The principle used for work/strain hardening has to do with residual strain.
With which parameter can you specify whether a metal is ductile …
To have either a ductile or brittle metal defines the failure mechanism which you can tell by having either a ductile fracture or a brittle fracture. Elongation and reduction of area as well as notch toughness (impact test) and hardness testing can give a quantitative value to ductility, by measuring the amount of energy the material absorbs ...
What's the difference between ductility and stiffness?
2024年1月9日 · Under an applied stress, a ductile material will deform permanently while a brittle material will break. Both modes are failure. The transition for ductile materials is the yield stress. The transition for perfectly brittle materials is the failure stress. A second mode of breaking called fracture is not identical to brittle failure.
A problem with quantifying ductility of a material
2021年9月25日 · Rubber is a hyperelastic material. It doesn't fall under the typical Ductile or Brittle categories. Percentage elongation and percentage reduction in length or area basically refers to permanent elongation or reduction, after the material has undergone any sort of plasticity (i.e. surpassing the yield strength of the material).
Strength vs. Hardness vs. Toughness - Engineering Stack Exchange
2019年2月12日 · So, Material 2 may have a lower strength than Material 1 but it is able to absorb more total energy before failure. Hardness = ability of a material to resist plastic deformation. Note that the sketch reflects two hypothetical (imaginary) material curves. Many other stress-strain curve profiles are possible.