Parabolic Flaws at Holes.
Final rept. Sep 81-Sep 84,
TECHNION - ISRAEL INST OF TECH HAIFA DEPT OF AERONAUTICAL ENGINEERING
Pagination or Media Count:
A parabolic crack shape, emanating from corner and embedded flaws at a hole in a plate of finite width, was analyzed by the slicing method. In contrast with other crack shapes, equilibrium solutions for a parabolic crack are finite and continuous as the crack passes the bottom of the hole and starts to propagate along the rear surface. Fracture parameters derived were K sub I for predicting fatigue crack growth along the plate surfaces and down the bore of the hole, and G sub I for residual strength. The four cases studied included a flaw a emanating from the corner of the hole, or b embedded in the side of the hole at the mid-depth, each case being either c remotely loaded, or d loaded at the hole. Derived fracture parameters and subsequently calculated fatigue crack curves were compared with experimental data and with calculated results obtained assuming on elliptically shaped crack. The parabolic crack analysis resulted in superior correspondence with measured data.