A failure analysis, based on fracture mechanics, may be useful for predicting the lifetime of a cord-reinforced rubber composite pneumatic tire. This paper presents a new three-dimensional Finite Element (FE) local model to calculate the energy release rate at the belt edge region. The new local model uses a three-dimensional (3D) Finite Element Modeling (FEM) fracture analysis based on a steady-state rolling assumption, in conjunction with a global-local technique in ABAQUS. Within the local model, a J-integral variation study is performed in the crack region. This consists of a prediction of the crack propagation direction and a mesh density analysis of the crack model. Furthermore, the study is used to determine the crack growth rate analysis. This study assumes that a flaw exists inside the tire, in the local model, due to a mechanical inhomogeneity introduced in the manufacturing of the tire. This paper also considers how different driving conditions, such as free-rolling, braking and traction, contribute to the detrimental effects of belt separation in tire failure.

Idealized structural unit method (ISUM) is now well recognized as one of the most efficient methods to analyze nonlinear behavior of large-sized structures under extreme or even accidental actions. This paper presents some techniques of ISUM modeling and surveys the literature on the ultimate limit state assessment of ship structures using ISUM. Theoretical formulations of ISUM elements for the progressive hull girder collapse analysis of ships that were implemented into ALPS/HULL computer code are outlined. Some benchmark studies are made by a comparison with physical test data and ALPS/HULL analyses on a frigate ship hull model under sagging moment tested by UK Royal Navy and on two double-skin tanker hull models under sagging or hogging moments tested by US Navy. Some ALPS/HULL application examples to progressive collapse analysis of a double-skin shuttle tanker hull under combined vertical and horizontal bending moments are then demonstrated. It is concluded that ISUM is very useful for the progressive hull girder collapse analysis of ships because it provides very accurate results while the computing time is very short.