This paper points out the disagreement of boundary conditions that generate force discontinuity in the linear spring damping contact model by analyzing the contact modulation of the clearance joint.
分析了含间隙运动副副元素的碰撞分离过程，指出线性弹簧阻尼模型不能满足接触边界条件并产生力突变；
2
They were all treated with straight wire appliance and helical spring to expand clearance.
均采用直丝弓矫治器矫治，应用螺旋推簧扩展间隙及上颌前方牵引。
3
In the operation of automatic spring coiling machine, the user needs to check the clearance between the parts, the use of the locking screw handle, screw tightening is loose.