An equation for the calculation of true shear strain was derived from the integration of infinitesimal shear strain in plane shearing process with constant principal shear strain direction.
对切应变主轴不变的平面简单切变过程，通过无穷小应变的积分，导出了真实切应变计算公式。
2
Corollary 1 The product of a constant and an infinitesimal is an infinitesimal.