An apparent or pseudo change in the sign occurs when a stress trajectory passes through an isotropic point.
当一个主应力迹线通过一个各向同性点时，该符号会发生一个表面上的或虚假的改变。
2
The pseudo-triaxial compression tests and confining pressure reduction tests were carried out for coal specimen strengths in different stress on servo-controlled testing machine.
基于在伺服试验机对煤样的常规三轴压缩和三轴卸围压试验，分析了煤样在不同应力条件下的强度和变形特征。
3
Under this framework, the stress-strain relations are derived from a pseudo-elastic strain-energy density.