Plastic hinge indicates the boundary of elastic and plastic domain moves to the fixed end at first but it will move back due to the interaction of reflected waves. 标志弹塑性边界的塑性效,一开始由自由端向固定端运动,但在反射卸载波的迎面作用下,会出现回退现象。
The boundary model occupies a spatial volume with a certain surface geometry, and moves as a rigid body in the prescribed manner. 边界模型具有特定的表面形状与结构,并按照既定的运转方式作刚体运动。