On the basis of model selection from the pieces tested and according to elastic mechanics, the relation between minute displacement and welding residual stress is deduced.
对所测试件选取适当的模型，应用弹性力学理论，推导出微小位移与焊接残余应力的关系式。
2
If the structure is elastic the force-displacement curve follows the same path on loading and unloading.
如果该结构为弹性，那么在加载和卸载时力位移曲线遵循相同的迹线。
3
As a important basis of calculating the distortion and strength of the buried pipeline, the paper gives out the space curve differential equations of elastic foundation-beam (displacement equation).