Direct simulation of thermo-coupled fatigue failure for metals

作者：Zhan, Lin; Wang, Si-Yu; Xi, Hui-Feng; Xiao, Heng^*

来源：ZAMM Zeitschrift fur Angewandte Mathematik und Mechanik, 2018, 98(6): 856-869.

DOI：10.1002/zamm.201700155

• direct simulation
• elastoplasticity
• fatigue failure
• metals
• thermomechanical processes

A new finite strain elastoplastic J2-flow model with thermo-coupled effects is proposed for the purpose of simulating cyclic and non-cyclic thermo-coupled fatigue failure behavior of metals. Novelties in four respects are incorporated in the proposed model: (i) the usual notion of yielding is rendered irrelevant with a smooth transition from the elastic to the plastic state; (ii) the thermodynamic consistency stipulated by the second law is identically ensured; (iii) asymptotic loss of the strength in cyclic and non-cyclic thermomechanical processes is incorporated as inherent constitutive features; and, accordingly, (iv) the fatigue failure behavior may be derived as direct consequences of the proposed model, without involving any additional failure criteria and any additional variables. Thermo-coupled responses of a metal bar with two fixed ends under cyclic heating and cooling over various temperature ranges are studied based on a simple case of the proposed model. Results are obtained for the maximum tensile and compressive stresses changing with the cycle number and, in particular, for the thermal fatigue life versus the temperature amplitude. Model predictions compare well with test data.

• 出版日期2018-6
• 单位上海大学; 暨南大学