The unexpected failures of structural materials in very high cycle fatigue (VHCF) regime have been a critical issue in modern engineering design. In this study, the VHCF property of a Cr-Ni-W gear steel was experimentally investigated under axial loading with the stress ratio of R = -1, and a life prediction model associated with crack initiation and growth behaviors was proposed. Results show ...

Fatigue crack growth (FCG) research conducted in the near threshold regime has identified a room temperature creep crack growth damage mechanism for a fine grain powder metallurgy (PM) aluminum alloy (8009). At very low ∆K, an abrupt acceleration in room temperature FCG rate occurs at high stress ratio (R = Kmin/Kmax). The near threshold accelerated FCG rates are exacerbated by increased levels...

Interfacial fracture toughness and cyclic fatigue-crack growth properties of joints made from 99.5% pure alumina partially transient liquid-phase bonded using copper/niobium/copper interlayers have been investigated at both room and elevated temperatures, and assessed in terms of interfacial chemistry and microstructure. The mean interfacial fracture toughness, Gc, was found to decrease from 39...

A software tool for automated crack onset and growth simulation based on the eXtended Finite Element Method (X-FEM) is developed. This XFA tool for the first time is able to simulate arbitrary crack growth or composite delamination without remeshing. The automated tool is integrated with Abaqus/Standard and Abaqus/CAE via the customization interfaces. It seamlessly works with the Commercial, Of...

In this study, based on a regression of the crack tip displacements, the stress intensity range in fatigue is quantitatively determined for the shape memory alloy Ni2FeGa. The results are compared to the calculated stress intensity ranges with a micro-mechanical analysis accounting for the transformation-induced tractions. The effective stress intensity ranges obtained with both methods are in ...

In recent years many experimental and numerical studies have been conducted on the fatigue behaviour of CNG storage pressure vessels. The main objective of these studies is to estimate the total fatigue life, which consists of two parts: i) Life till crack nucleation and ii) Crack growth life. Although fatigue evaluation methods for metal cylinders are widely covered in literature including the...

The effects of anisotropy during mixed mode fatigue crack growth were studied in single crystal 316L stainless steel. An anisotropic least-squares regression algorithm using displacements from digital image correlation was developed to find the effective stress intensity factors, KI and KII, and the T-stress. Crack tip plastic zones were determined using an anisotropic yield criterion. Strains ...

Preliminary testing of a complete landing gear under fatigue test has demonstrated the applicability of the test using Acoustic Emission (AE) resonant sensors attached to the outer surface of the landing gear assembly. Attenuation trials were conducted which confirmed that attenuation through the main casing is low and provided data for optimisation of sensor positioning. Background noise level...

The present paper is concerned with the application of a “plasticity-induced” crack closure model to study fatigue crack growth under various load histories. The model was based on the Dugdale model but modified to leave plastically deformed material in the wake of the advancing crack. The model was used to correlate crack growth rates under constant-amplitude loading and then used to predict c...