Zhao Wen-zhen

New formula relating the yield stress-strain with the strength coefficient and the strain-hardening exponent

The main purpose of this paper is to search formulas for different metals that relate the yield stress-strain with the strength coefficient and the strain-hardening exponent. For this purpose, the test data of nine alloys were used as basic data and the applicability of Hollomon’s equation at the yield point of the alloy was studied. This paper explores new equations relating the yield stress-strain with the strength coefficient and the strain-hardening exponent. At the same time, the study introduces a new fracture-ductility parameter. The new fracture-ductility parameter not only describes the applicability of the new equations to these alloys, but may also be better at describing the hardening behavior of a metallic material.The main purpose of this paper is to search formulas for different metals that relate the yield stress-strain with the strength coefficient and the strain-hardening exponent. For this purpose, the test data of nine alloys were used as basic data and the applicability of Hollomon’s equation at the yield point of the alloy was studied. This paper explores new equations relating the yield stress-strain with the strength coefficient and the strain-hardening exponent. At the same time, the study introduces a new fracture-ductility parameter. The new fracture-ductility parameter not only describes the applicability of the new equations to these alloys, but may also be better at describing the hardening behavior of a metallic material.

Influence of Combination of Casimir Force and Residual Stress on the Behaviour of Micro- and Nano-Electromechanical Systems

Casimir force and residual stresses actually appear in over-layers or films simultaneously. The study of the behaviour of micro- and nano-electromechanical systems in the presence of Casimir force and residual stress is of significance to the design of the relevant devices. We derive analytical expressions of the deflection of a bridge-shaped device under the mutual actions of Casimir force and residual stress in films. It is shown that the tensile residual stress enhances wavy behaviour of the deflection, while the compressive residual stress increases the deflection value and reduces the wavy behaviour.