Loading of the rat ulna is an ideal model to examine stress fracture healing. The aim of this study was to undertake a detailed examination of the histology, histomorphometry and gene expression of the healing and remodelling process initiated by fatigue loading of the rat ulna. Ulnae were harvested 1, 2, 4, 6, 8, and 10 weeks following creation of a stress fracture. Stress fracture healing inv...

Heavily boron-doped silicon microstructures fabricated using deep-boron diffusions and boron etch-stops have been widely used in a variety of integrated sensors and actuators. For many applications, having knowledge of the mechanical properties such as Young's modulus, intrinsic stress, and fracture stress of these films is very important in predicting the response parameters of the sensors and...

The propensity of the transition of fracture type in either brittle or ductile cracked solid under mixed-mode I and III loading conditions is investigated. A fracture criterion based on the competition of the maximum normal stress and maximum shear stress is utilized. The prediction of the fracture type is determined by comparing smax=rmax at a critical distance from the crack tip to the materi...

In several practical cases, the ultimate ductile fracture strain determined with tensile test is accepted as a material plasticity measure 1 . In this case, the plasticity has to be defined as an ability of a material to accommodate high permanent strains until fracture appears where this strain reaches certain value called ultimate fracture strain p. The strain value until fracture depends not...

A new test method has been developed to measure the resistance of dynamic fracture initiation in brittle materials under combined mode I/I loadings. The Brazilian disks with center-cracks have been fractured under oblique impact loadings in diarnetral-compression. The dynamic stress intensity factors of mode I and H are evaluated from the superposition integrals of the step response functions f...

numerical methods such as boundary element and finite element methods are widely used for the stress analysis in solid mechanics. this study presents boundary element method based on the displacement discontinuity formulation to solve general problems of interaction between hydraulic fracturing and discontinuities. the crack tip element and a higher order boundary displacement collocation techn...

Stress fracture of the proximal tibia after total knee arthroplasty (TKA) is very rare. We found only 16 cases in a review of the literature. We report the case of a 76-year-old obese woman who sustained a stress fracture of the right proximal tibia without trauma 18 months after TKA. Pain developed in the proximal medial aspect of the tibia during walking. Physical examination showed tendernes...

Modeling of crack propagation by a finite element method under mixed mode conditions is of prime importance in the fracture mechanics. This article describes an application of finite element method to the analysis of mixed mode crack growth in linear elastic fracture mechanics. Crack - growth process is simulated by an incremental crack-extension analysis based on the maximum principal stress c...

In our study, the aims were to describe the changes in the appearance of the lumbar spine on MRI in elite fast bowlers during a follow-up period of one year, and to determine whether these could be used to predict the presence of a stress fracture of the posterior elements. We recruited 28 elite fast bowlers with a mean age of 19 years (16 to 24) who were training and playing competitively at t...

This paper describes algorithms for threedimensional dynamic stress and fracture analysis using the material point method (MPM). By allowing dual velocity fields at background grid nodes, the method provides exact numerical implementation of explicit cracks in a predominantly meshless method. Crack contact schemes were included for automatically preventing crack surfaces from interpenetration. ...