Analysis of failed K-95 horn diaphragm

A failed K-95 horn diaphragm was sent to the laboratory to analyse the cause of failure. The horn diaphragm had a crack along the diameter through the central hole. Examination revealed that the diaphragm has failed by fatigue. Fatigue was found to be of high cycle – low stress type. Analysis showed that there were some pre-existing cracks around the periphery of the central hole which have propagated by fatigue under cyclic load. It appears most probable that these cracks were generated during fixing the diaphragm in the assembly