一种形状记忆合金的本构模型及其应用(英文)

Constitutive Relationship and Appl ications of Shape-memory Alloys

建立1种本构模型,用于研究形状记忆合金(SMA)结构和复合材料的力学响应。首先,该本构模型在单轴应力状态和多轴应力状态下得到考核;其次,给出了移植到ABAQUS的用户子程序umat的求解格式。利用有限元方法分析了SMA的CT(紧凑拉伸)和TPB(三点弯曲)试样以及SMA—纤维增强复合材料和常规金属合金增强SMA基复合材料的力学响应。在CT和TPB裂纹前端,有不同的相变规律,SMA复合材料的相变取决于应力状态和两相材料的材料性质等。

A constitutive relationship has been applied to study the behavior of structures and composites of the shape-memory alloy (SMA). The predictability of the constitutive relationship is confirmed by the uniaxial and multiaxial examples. The paper gives out the finite element algorithmic implementations, which is applied to implement as umat of ABAQUS. As two kinds of applications, CT (compact tensile) and TPB (three point bending) specimens and SMA-fiber reinforced metal matrix and metal-fiber reinforced SMA-matrix composites are analyzed. The different distributions of martensite fraction of the CT specimens and TPB-specimens made of SMAs are explained by the-different stress characteristics ahead the cracks. The relative study on the SMA composites shows that the bulk mechanic behavior depends on the volume of SMA and the non-SMA matrix/fiber properties.