Fatigue strength of hard-chromium-plated handlebars

摘要

Prototypes of handlebars for motorcycles were fabricated by rotary bending and hard-chromium electrodeposition. Fatigue tests were carried out on rough handlebars and hard-chromium plated handlebars; the former resisted over 200.000 cycles, the latter failed at about 50.000 cycles. Scanning Electron Microscopy (SEM) allowed one to observe the presence of sub-surface cracks, which probably originated during the tube bending. Moreover numerical simulation permitted one to identify the occurrence of buckling during the bending process. The combination of buckling, cracks and residual stresses from the chromium electrodeposition results in a very poor behaviour of the handlebar under fatigue test.