Effect of thermal residual stresses on ductile-to-brittle transition of a bi-material specimen by using the CAFE method
Effect of thermal residual stresses on ductile-to-brittle transition of a bi-material specimen by using the CAFE method
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DOI：
10.1016/j.euromechsol.2019.103889
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发表时间：
2020-03
影响因子：
4.1
通讯作者：
Yang Li;X. Ren;Jianying He;Zhiliang Zhang
中科院分区：
文献类型：
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作者：
Yang Li;X. Ren;Jianying He;Zhiliang Zhang
残余应力对材料或结构断裂的影响已被广泛研究。然而，它对结构材料的一个重要现象-韧脆转变（DBT）的影响却很少被研究。在本研究中，采用本征应变法将残余应力引入到双材料试件中，其中裂纹和界面的两种构型，一个界面垂直于裂纹扩展方向，另一个界面平行于裂纹扩展方向，用来研究残余应力的影响。采用CAFE方法对双材料试样在残余应力作用下的DBT进行了数值研究，该方法采用温度依赖的表面能计算夏比冲击试样的吸收能量。结果发现，在两种配置中产生的残余应力影响DBT以类似的方式。随着残余应力的增加，吸收能量减少，DBT曲线向高温方向移动。结果表明，两种结构下吸收能量的降低是由于残余应力对缺口根部产生了附加约束，从而促进了缺口的断裂。
The effect of residual stress on fracture of materials or structures has been widely studied. However, its influence on ductile-to-brittle transition (DBT), a crucial phenomenon of structural materials, has rarely been investigated so far. In the present study, employing the eigenstrain method residual stresses are introduced into a bi-material specimen, where two configurations of crack and interface, e.g., one with interface perpendicular and one parallel to the crack extension, are designed to study the influence of residual stress. The DBT of the bi-material specimen in the presence of residual stresses is numerically studied by using the CAFE method where temperature dependent surface energy is implemented to calculate absorbed energy of Charpy impact testing specimen. It is found that residual stress generated in the two configurations affect the DBT in a similar manner. The DBT curves generally shift to higher temperature due to the decrease of absorbed energy with the increase of residual stress. It is found that the decrease of absorbed energy in both configurations is caused by the additional constraint on the notch root, which is induced by the residual stress and can facilitate the fracture.