In this paper the TMF crack initiation behaviour of the single-crystal nickel-base superalloy MD2 is investigated and modelled. TMF tests were performed in both IP and OP for varying mechanical strain ranges in the [001] crystallographic direction until TMF crack initiation was obtained. A crystal plasticity-creep model was used in conjunction with a critical-plane approach, to evaluate the num...

Bone fracture is a health concern for those with aged bone and brittle bone diseases. Mouse bone is widely used as a model of human bone, especially to investigate preclinical treatment strategies. However, little is known about the mechanisms of mouse bone fracture and its similarities and differences from fracture in human bone. In this work we present a methodology to investigate the fractur...

Hip replacements provide a means of achieving a higher quality of life for individuals who have, through aging or injury, accumulated damage to their natural joints. This is a very common operation, with over a million people a year benefiting from the procedure. The replacements themselves fail mainly as a result of the mechanical loosening of the components of the artificial joint due to dama...

A system for ultrasonic fatigue testing at temperatures as high as 700 C and at positive mean stresses has been developed. Its use is demonstrated by examining the fatigue behavior in the lifetime range of 10 to 10 cycles for the nickel-base superalloy Rene' 88 DT at 20 and 593 C for a load-ratio of 0.05. Crack initiation occurred from large grains and from inclusions, consistent with crack ini...

Fretting fatigue process have many features such as early stage crack initiation at contact edge, very slow crack propagation and fatigue failure after very long life operation. In this paper at first we present fretting fatigue model in high cycle region, which is considering the wear process near contact edge. And then we present fretting fatigue life estimation method in low cycle fatigue re...

This paper presents a single-domain boundary element method SDBEM for linear elastic fracture mechanics analysis in the 2D anisotropic bimaterial. In this formulation, the displacement integral equation is collocated on the uncracked boundary only, and the traction integral equation is collocated on one side of the crack surface only. The complete fundamental solution Green’s function for aniso...

The phenomenon of fatigue in gears at the tooth root can be a cause of catastrophic failure if not detected in time. Where traditional low-frequency vibration may help in detecting a well-developed crack or a completely failed tooth, a system for early detection of the nucleation and initial propagation of a fatigue crack can be of great use in condition monitoring. Acoustic emission is a poten...

Abstract Background Crack-cocaine dependence is a serious public health issue, related to several psychiatric and psychosocial problems. users are usually embedded in context of great social vulnerability, often associated with violence, poverty, family conflict easy early access alcohol, tobacco other drugs. Methods This cross-sectional study enrolled consecutive sample 577 patients admitted 2...

In this study, the damage fields near the crack tip in edge-cracked sheet specimens subjected to a constant strain rate of 0.05 min were investigated using real-time radiographic techniques. During the tests, Lockheed-Martin Advanced Technology Center’s high-energy real-time x-ray system (HERTIS) was used to monitor damage initiation and evolution processes near the crack tip. The experimental ...