Abaqus软件中，切削运行仿真时，碰到如下错误，这是怎么回事？

Error in job nab: The elements contained in element set ErrElemExcessDistortion-Step1 have distorted excessively.Error in job nab: The elements in element set ErrElemZeroALEMass-Step1 have zero or negative mass.Error in job nab: There are a total of         7 excessively distorted elements.Job nab: Abaqus/Explicit aborted due to errors.