The interest in predicting the force required for a subsea blowout preventer (BOP) to cut and isolate the drilling pipe has been growing since the Macondo accident. In previous research, numerical simulation using the nonlinear finite element method combined with the blowout preventer (BOP) shear test has been a common approach. As various fracture criteria exist, the selection and application of a suitable fracture criterion are of great interest to achieve a successful ram shearing simulation. In this paper, the CrashFEM criterion, previously employed in crashworthiness simulation, is first adopted in BOP ram shearing simulation to capture the onset of damage to the pipe. The Johnson-Cook (J-C) and Modified Mohr-Coulomb (MMC) criteria are utilized to carry out a comparative study. The TRIP 690 experimental data are used to derive the fracture parameters. These parameters enable the building of numerical models based on boundary and loading conditions for the BOP shear test. Based on the numerical model, a mesh sensitivity study is carried out. The simulation results using refined meshes show that the shearing forces predicted by the CrashFEM and MMC criteria are generally consistent with the experimental data. The results from the three criteria indicate differences originating from the shape of the fracture limit curve, the damage initiation concerning the equivalent plastic strain accumulation, and the damage distribution in the shearing area. These findings are explained in detail in the paper. A comprehensive application of the CrashFEM criteria for BOP shearing simulation is presented and recommendations are provided about the selection of suitable fracture criteria.

自Macondo事故以来，人们对预测海底防喷器（BOP）切断和隔离钻杆所需的力的兴趣日益增长。在以前的研究中，使用非线性有限元方法与防喷器（BOP）剪切试验相结合的数值模拟是一种常见的方法。由于存在各种断裂判据，因此选择合适的断裂判据并加以应用对于成功完成夯剪模拟非常重要。在本文中，先前在防撞性仿真中采用的CrashFEM准则首先在BOP闸板剪力仿真中采用，以捕获对管道损坏的发生。利用Johnson-Cook（JC）和改良的Mohr-Coulomb（MMC）标准进行比较研究。TRIP 690实验数据用于导出断裂参数。这些参数使得能够基于边界和载荷条件为BOP剪切试验建立数值模型。基于数值模型，进行了网格敏感性研究。使用精制网格的模拟结果表明，由CrashFEM和MMC标准预测的剪切力通常与实验数据一致。这三个标准的结果表明，差异源自断裂极限曲线的形状，与等效塑性应变累积有关的损伤萌生以及剪切区域中的损伤分布。这些发现将在本文中详细解释。