background at altnagelvin, a district general hospital in northern ireland, we have observed that a significant number of hip fracture admissions are later readmitted for treatment of other medical conditions. these readmissions place increasing stress on the already significant burden that orthopedic trauma poses on national health services. objectives the aim of this study was to review a ser...

This article aims to compare three plasticity models, namely Bai-Wierzbicki (BW), von Mises and Drucker Prager, predict the failure modes in double-lap metallic bolted joints under shear loading. The joint finite element model has been validated against literature data, which demonstrated application of BW ductile fracture bolt prediction. Taguchi Design is used investigate effects geometrical ...

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...

Abstract In the present study, a hypoelastic–plastic formulation of porous crystal plasticity with regularized version Schmid’s law is proposed. The equation describing effect voids on modified to allow for an explicit analytical solution effective resolved shear stress. model implemented as material in finite element code using cutting plane algorithm. Fracture described by erosion at critical...

carpal fracture-dislocation is regarded as an unusual orthopedic injury and, thus, orthopedic surgeons are less experienced in dealing with and treating these fractures and dislocations. we report a 20-year-old worker man suffering from an unusual carpal fracture-dislocation. there was trans-scaphoid fracture and lunate dislocation with other carpal proximal bones toward volar of the wrist. two...

BACKGROUND There is currently little information regarding factors associated with specific modes of motion segment failure using a fatigue failure model. METHODS Thirty-six human lumbar motion segments were fatigue tested using spinal compressive and shear loads that simulated lifting a 9 kg weight in three torso flexion angles (0 degrees, 22.5 degrees, and 45 degrees). Twenty-five segments ...

The purpose of this study was to investigate how water aging of the resin cement influences the stress distribution in all-ceramic crowns and if there is an increase in the propensity for crown failure. The failure of all-ceramic crowns attributed to cement degradation was explored using a combination of experimental and numerical methods. Sectioned all-ceramic crown specimens were fabricated o...

A welded rectangular hollow section (RHS) X-joint exposed to tension loading has three typical fracture-related failure modes: Punching shear (PSF), Brace (BF), and Chord side wall (CSWF). Prediction of these modes by finite element (FE) simulations requires modelling the material damage. An appropriate damage model accurately predicts behaviour fracture zone provides necessary information impr...

The fracture toughness and strength of ceramics can be improved with respect to monolithic ceramics by developing graded materials as laminates composed of periodic alternating layers of one material separated by layers of a second material. The second layer must contain residual compressive stresses which are induced during densification because of differential thermal contraction of the layer...