Does spring wire creep? Will your mechanical springs lose their elasticity when placed under stress for long periods of time? Both of these questions are important to answer because spring failure can leads to disastrous results.
If you are new to the physics of a spring, or are unaware of spring fatigue, know that material creep is a legitimate concern engineers have. When a material “creeps,” it essentially deforms very slowly over time, losing its strength (or elasticity, in the terms of a spring). When a constant mechanical stress is added to a material, it causes the material to move slowly or deform over time. While temporarily deforming and then returning to a state of rest is the sheer definition of the purpose of a spring, deformation can happen when too much force is applied to a spring.
Think about pulling apart a small spring and stretching it to a point where it does not spring back to its normal state.
While deformation will always occur when too much force is applied to virtually any material, creep is not concerned with large, overbearing forces. Creep is when materials deform when a smaller, unyielding force is applied to a material for extended periods of time. It’s essentially the difference between elastic deformation (which springs are designed to handle) and plastic deformation (which causes permanent damage to springs).
Think of a compression spring being compress by a force it is designed to handle, but that force never lets up and is left on the spring for years. The question is: will this spring deform (creep) and be unable to return to its normal state if the force is removed from it after several years?
Do Spring Materials Creep?
If your springs are specially designed for your application, they shouldn’t experience creep. This is because custom springs are designed to be made from the materials and have the design specifications that can handle the loads being applied to them and the conditions they are placed in. Keep in mind that temperature is a big factor in creep, but if you are using the right spring wire that has been conditioned in the right way, your springs should be able to handle the environment. The same can be said of the load they are handling. Custom springs will have a deflection that can handle the stress being placed on it.
Working with the Right Partner
To reduce the threat of spring failure, fatigue and creep, work with a spring manufacturer who properly tests their springs for creep and ensure you get a fully customized spring that is able to handle the loads your application will place on it. The Yost Superior Co. is that partner. We can fulfill all your spring needs with the best parts on the market. Contact us today for a free engineering consultation and spring quote.