Miner´s Rule in Mechanical Tests of Electronic Parts

The complexity and cost of equipment necessary for dynamic mechanical strength testing is reviewed. The influence of mechanical resonance on the behaviour of electronic components is discussed. On the basis of Miner´s rule (linear cumulative fatigue damage), the conditions for equivalent tests (shock, vibration by sweeping, and vibration below resonance frequency) are presented. The results of mechanical resonance measurements of electronic parts and of their life test are given. The test times for different methods are compared. On the basis of experimental results some conclusions are proposed, particularly that vibration tests at constant frequency are not useful.