基于ABAQUS平台考虑T应力的I型裂纹扩展模拟开发

DEVELOPMENT OF MODE-I CRACK PROPAGATION SIMULATION CONSIDERING T-STRESS BASED ON ABAQUS PLATFORM

  • 摘要: 工程结构在制造工艺过程中或使用期间会产生裂纹,对结构断裂路径的预测和研究是防治工程安全问题发生的重要手段。在考虑裂纹尖端应力场常数项T应力的基础上对传统的最大周向应力准则(Maximum tangential stress criterion, MTS)和最小应变能密度因子准则(Minimum strain energy density criterion, SED)进行修正,采用Python语言对ABAQUS的前、后处理和有限元计算模块进行二次开发,通过计算最优解的粒子群算法(Particle swarm optimization, PSO)将修正后的准则编入裂纹自动扩展程序脚本中。利用上述二次开发程序对初始纯I型裂纹的扩展路径进行模拟,结果表明:采用ABAQUS脚本程序模拟结果与相关文献实验结果吻合,表明了程序的有效性,进而实现考虑T应力的多种断裂准则对裂纹扩展路径的预测;当T应力值处于一定范围内时,修正的MTS准则无法预测裂纹发生的偏转现象,扩展路径呈直线,此时可采用修正的SED准则进行预测。

     

    Abstract: Cracks will develop in engineering structures during construction or in service. Prediction and research of fracture paths are crucial to prevent and control engineering safety issues by taking into account the stress field constant term T-stress at the crack tip. The traditional Maximum Tangential Stress (MTS) and the Minimum Strain Energy Density (SED) criterion are modified, while the secondary development of ABAQUS's pre-processing, post-processing, and finite element calculation modules is carried out using Python. The updated criterion is incorporated into the automatic crack propagation program's script by the solution's Particle Swarm Optimization algorithm (PSO). The propagation path of the first pure mode-I crack is simulated using the previously mentioned secondary development tool. The results indicate that: The simulation results of the ABAQUS script program are in agreement with the experimental findings of the relevant literature, demonstrating the program's usefulness before realizing the multi-dimensional propagation taking T-stress into account; The modified MTS criterion cannot forecast the deflection phenomena of fractures when the T-stress value is within a specified range, and the propagation path is straight. The updated SED criterion can be applied to make predictions.

     

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