Interest in extending the high cycle fatigue life of structures has increased in the last decade of the 20th century. Since a long fatigue life depends on keeping cyclic loads near or below the fatigue threshold, understanding near-threshold behavior is now all the more important. This paper reviews the status of the ‘threshold of fatigue’ and to a lesser extent its relation to the ‘fatigue lim...

Electronic power devices used for transportation applications (automotive and avionics) experience severe temperature variations, which promote their thermal fatigue and failure. For example, for power modules mounted on the engine of an aircraft, temperature variations range from –55°C (in the worst case of storage before takeoff) to +200°C (flight). Direct bonded copper (DBC) substrates are u...

in this paper, the mean value of strain energy density criterion has been used to predict the critical fracture load in specimens with u-shaped notch under bending loads. an equation for calculation of averaged strain energy density in this zone has been presented. bending loads under mode i have been considered. two cases have been studied: 1) the control volume only includes the semicircular ...

The aim of this paper is to simulate the propagation linear elastic crack in 3D structures using latest innovation developed Ansys software, which Separating Morphing and Adaptive Remeshing Technology (SMART), order enable automatic remeshing during a simulation fracture behaviors. ANSYS Mechanical APDL 19.2 (Ansys, Inc., Canonsburg, PA, USA), used by employing special mechanism ANSYS, smart gr...

This paper presents the implementation of eXtended Finite Element Method (XFEM) in general-purpose commercial software COMSOL Multiphysics for first time. An enrichment strategy is proposed, consistent with structure software. To this end, each set functions, an additional Solid Mechanics module incorporated into numerical framework, coupled compatible modifications to internal variables. The L...

Background: Linear elastic fracture mechanics (LEFM) applies to sharp cracks, although crack sites such as holes and slots are often blunt cracks with nonzero widths. The advancement in finite element method (FEM) has enabled the calculation of stress intensity factor (SIF) for unstable growth prediction, regardless shape size, but calculations differ from contour co...

Osteogenesis imperfecta (OI) is a genetic disease of collagen or collagen-related proteins that adversely impacts bone mass and fracture resistance. Little is known regarding the role that microdamage plays in OI and whether or not OI bone is more prone to damage accumulation than bone with unaffected collagen. The Brtl/+ mouse is a heterozygous model for OI which contains a Gly349Cys substitut...