The law of compression

How to determine the compression amount of spring under strong pressure:
With the increase of load, the surface shear stress of cylindrical spiral compression spring increases gradually until it exceeds the elastic limit of the material and plastic deformation occurs, and the elastic limit of the material is gradually reached near the core. After unloading, due to the influence of plastic deformation of the outer layer of the material, it can not completely recover to its original state, resulting in residual deformation.

When the spring works, the stress in the center of the material increases and the stress on the surface decreases. The change of the stress can give full play to the potential of the material. In the design of normal spring, the limit deformation of spring is generally considered, which will not exceed the limit stress of spring. The spring’s allowable stress varies with the material’s allowable shear stress, and the spring’s load category is different.

The specific calculation can be based on the calculation formula of deformation and shear stress of spring under axial load. If it is less than the limit value, the spring can be compressed. If it is greater than the limit value, the maximum compression amount is the limit value. Beyond the limit value, the spring will produce permanent deformation.