Comparison between fracture parameters of an all-aluminum cylinder with cracks under different deformation conditions

Linear elastic and nonlinear elastic-plastic fracture mechanics calculation s have been carried out on an all-aluminum gas cylinder design by three-dim ensional finite element analyses. Axial cracks in the cylindrical portion s ection and circumferential cracks at the base of the cylinder have been mod eled with the crack depth to wall thickness ratio varying between 0.225 and 1, and for the crack length being five times the wall thickness. Values of crack mouth opening displacement (CMOD), and the crack driving forces (J-i ntegral for elastic-plastic deformation state, stress intensity factor for elastic deformation state) have been obtained for these cracks under variou s levels of internal pressure. Comparisons have been made between the resul ts of the different cases considered, and also with some available experime ntal results. (C) 2000 Elsevier Science Ltd. All rights reserved.