Related Experiment Video
Updated: May 29, 2026

Determining the Mechanical Strength of Ultra-Fine-Grained Metals
Published on: November 22, 2021
Ideal shear strength under compression and tension in C, Si, Ge, and cubic SiC: an ab initio density functional
Y Umeno1, Y Shiihara, N Yoshikawa
1Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba Meguro-ku, Tokyo 153-8505, Japan. umeno@iis.u-tokyo.ac.jp
Abstract:
Ideal shear strength under superimposed normal stress of cubic covalent crystals (C, Si, Ge, and SiC) is evaluated by ab initio density functional theory calculation. Shear directions in [112] and [110] on the (111) plane are examined. The critical shear stress along the former direction is lower than that along the latter in all the crystals unless the hydrostatic tension is extremely high. In both the [112]-shear and [110]-shear, critical shear stress is increased by compression in C but is decreased in the other crystals. The different response of the critical shear stress to normal stress is due to the strength of the bond-order term, i.e., dependence of the short-range interatomic attraction on the bond-angle.
Related Concept Videos
Shearing Strain
Yield Criteria for Ductile Materials under Plane Stress
The Maximum Shearing Stress Criterion, also known as the...
Behavior of Concrete Under Compressive Load
As the concrete specimen fractures under...
Problem Solving on Stress and Strain
Relation Between Tensile Strength and Compressive Strength of Concrete
Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity

