Design rules for autofrettage of an aluminium valve body

The following paper is intended to improve the fatigue behaviour of a complex aluminium
valve geometry under high internal cyclic pres sure loading. The autofrettage process helps
to increase the f atigue durability and a simple, but efficient design method for this proces s
is deployed. Based o n non-linear material’s behaviour, fin ite eleme nt simulations of t he
crack-free geometry help to determine the minimum and maximum autofrettage pressure
to be used, without iterative crack simulations , which would require higher computational
effort. Material tests under inverse plastifications were performed in order to determine the
correct material model. The derived design method was validated with simplified specimens
subjected to different autofrettage pressure levels and su bsequent cyclic fatigue tests.