Fatigue Modeling for Superelastic NiTi Considering Cyclic Deformation and Load Ratio Effects

被引：13

作者：

Mahtabi M.J. ^{[1
,2
]}

Shamsaei N. ^{[3
]}

机构：

[1] Department of Mechanical Engineering, Mississippi State University, Mississippi State, 39762, MS

[2] Center for Advanced Vehicular Systems (CAVS), Mississippi State University, Mississippi State, 39762, MS

[3] Laboratory for Fatigue & Additive Manufacturing Excellence (FAME), Department of Mechanical Engineering, Auburn University, Auburn, 36849, AL

来源：

Shape Memory and Superelasticity | 2017年 / 3卷 / 03期

基金：

美国国家科学基金会;

关键词：

Energy method; Fatigue; Life prediction; Mean stress; Nitinol; Shape memory alloy; Superelasticity;

D O I：

10.1007/s40830-017-0115-2

中图分类号：

学科分类号：

摘要：

A cumulative energy-based damage model, called total fatigue toughness, is proposed for fatigue life prediction of superelastic NiTi alloys with various deformation responses (i.e., transformation stresses), which also accounts for the effects of mean strain and stress. Mechanical response of superelastic NiTi is highly sensitive to chemical composition, material processing, as well as operating temperature; therefore, significantly different deformation responses may be obtained for seemingly identical NiTi specimens. In this paper, a fatigue damage parameter is proposed that can be used for fatigue life prediction of superelastic NiTi alloys with different mechanical properties such as loading and unloading transformation stresses, modulus of elasticity, and austenite-to-martensite start and finish strains. Moreover, the model is capable of capturing the effects of tensile mean strain and stress on the fatigue behavior. Fatigue life predictions using the proposed damage parameter for specimens with different cyclic stress responses, tested at various strain ratios (Rε = εmin/εmax) are shown to be in very good agreement with the experimentally observed fatigue lives. © 2017, ASM International.

引用

页码：250 / 263

页数：13