Notes on the experimental measurement of fracture toughness of shape memory alloys
Notes on the experimental measurement of fracture toughness of shape memory alloys
复制标题
形状记忆合金断裂韧性实验测量注意事项
DOI：
10.1177/1045389x19888730
复制
发表时间：
2020
影响因子：
2.7
通讯作者：
T. Baxevanis
中科院分区：
文献类型：
--
作者：
J. Makkar;T. Baxevanis
最近提出了一种用于测量形状记忆合金断裂韧性的机械辅助测试方法，其变形/失效响应违反了用于测量常规延性材料断裂韧性的ASTM标准的基本假设。所提出的方法依赖于ASTM标准的阻力曲线格式，但不同于它在确定的J值的弹性部分，为静止和前进的裂纹，在努力适应的转变/取向引起的变化的表观弹性性能。本文讨论了拟议的修改ASTM标准，即预期程度的改善测量精度，需要进一步的不确定性，在哪里指定断裂点上获得的阻力曲线，试样厚度要求，以确保保守的，约束无关的测量，和温度依赖性的测量。
A mechanics-aided test method for measuring the fracture toughness of shape memory alloys, the deformation/failure response of which violates basic assumptions of ASTM standards for measuring fracture toughness in conventional ductile materials, has been recently proposed. The proposed methodology relies on the resistance curve format of ASTM standards, but differs from it in the determination of the elastic part of the J value, for both stationary and advancing cracks, in an effort to accommodate the transformation/orientation-induced changes in the apparent elastic properties. This article discusses the proposed modifications to ASTM standards, that is, the expected degree of improvement in the measurement accuracy, the need for further ones regarding the uncertainty as to where to specify the fracture point on the obtained resistance curve, the specimen thickness requirement to ensure a conservative, constraint-independent measurement, and the temperature dependence of the measurements.