含单个Ⅰ型裂纹的高温超导块材应力强度因子修正及计算  

COORECTION AND CALCULATION OF STRESS INTENSITY FACTOR OF HTS BLOCK WITH SINGLE TYPE I CRACK

作　　者：王楚斐 WANG Chufei(School of Mechano-Electronic Engineering,Xidian University,Xi’an 710000,China)

机构地区：[1]西安电子科技大学机电工程学院,西安710000

出　　处：《力学与实践》2023年第2期373-378,共6页Mechanics in Engineering

摘　　要：高温超导块材在外磁场下降过程中会受到拉伸应力的作用,可能导致其断裂,且其在受到拉伸应力作用时裂纹尖端产生小范围屈服,此时用线弹性理论计算应力强度因子将不准确。本文通过统一强度理论对裂纹尖端塑性区的应力强度因子计算公式进行修正。随后基于Bean模型分别讨论了外磁场变化速率和外磁场大小对应力强度因子的影响。结果表明高温超导块材充磁过程中,外磁场以较小速率下降时主要考虑外磁场下降速率对裂纹扩展的影响,当外磁场较大时,主要考虑外磁场大小对裂纹扩展的影响。本文结果对高温超导块材充磁过程中的裂纹扩展和应力强度因子的计算具有一定的参考价值。In the process of the external magnetic field falling,the high temperature superconducting(HTS)block will be affected by tensile stress,which may lead to fracture,and the crack tip will yield in a small range under the action of tensile stress.In this case,it will be inaccurate to calculate the stress intensity factor(SIF)using the linear elasticity theory.In this paper,the formula of SIF in plastic zone of crack tip is modified by the unified strength theory.Then,based on the Bean model,the influence of external magnetic field change rate and external magnetic field size on stress intensity factor is discussed respectively.The results show that when the external magnetic field decreases at a small rate,the effect of the external magnetic field on the crack growth should be mainly considered.When the external magnetic field decreases at a large rate,the effect of the external magnetic field on the crack growth should be mainly considered.The results presented in this paper have certain reference value for the calculation of crack propagation and stress intensity factor in the magnetizing process of HTS blocks.

关 键 词：高温超导块材 应力强度因子 裂纹扩展 外磁场变化速率 

分 类 号：O34[理学—固体力学] O511[理学—力学]