Numerical analyses of breech pressure chambers with cavities or semi-elliptical cracks

Abstract

Numerical failure analyses are presented for jet engine starter's breech pressure chambers. Several models with and without semi-elliptical flaws are investigated by using a three-dimensional elastic-plastic finite element program. Some results are compared with the corresponding experimental strain measurements. These analyses provide yielding and burst pressure, and other information which relate to the cause of the premature failure in the breech pressure chambers. A slight modification in the geometry of the cylindrical pressure vessel with quasi-spherical head is shown to drastically reduce the yielding and burst pressures especially for large pre-existing semi-elliptical cracks.