Nice to meet you.
I am an amateur in spring calculation, so I am struggling with the idea of stress. For the stress generated in a normal compression spring, the torsional stress is calculated assuming that a straight load is applied to the spring. However, when the spring is used without being fixed, it can be imagined that a bending load is applied to the spring due to various causes such as the direction of the load (uneven load), the accuracy of the spring, and the buckling of the spring. There are also examples that assume such usage from the beginning. How should we consider the stress generated in the spring when used in this way? Does torsional stress increase? Does the stress here equal torsional stress + bending stress (tensile stress)? Could you tell me the calculation formula? What should I do about tolerance? Normally, I feel that this is not a problem by ensuring a sufficient safety factor, but I would like to know the stress that will actually occur. If the stress due to the bending load is concentrated in one place, I feel that something scary will happen.
Hirouhakai, thank you for writing to us!
Unfortunately, there is no formula for calculating when a bending load is applied to the springs. Compression springs are basically used by applying a load vertically, so if there is a possibility that bending occurs significantly, it may be necessary to take measures such as providing a guide. If it is necessary to use it in such a way that bending is applied, I think it is necessary to make the specifications with the calculated torsional stress value considerably reduced.
