Mechanical Systems and Signal Processing vol:4 issue:2 pages:131-143
A practical problem of fracture of a mechanical component is examined. Full attention is paid to the dynamic aspects of the problem, which is a typical case of resonance fatigue. The fatigue aspects of the problem are briefly mentioned. The component is loaded by a series of multiple impulses. The dimensions of the object are very small and so modal analysis has to be performed using the finite element method. Stress analysis is done with the boundary element method. Several design modifications are presented. It is shown why structural modifications are unable to increase the life of the structure unless the frequency contents of the load input is altered, the lifetime remains unacceptably low. Other measures have then to be taken and the only modification that is able to increase the lifetime significantly is the choice of a material with better fatigue properties.