conclusions surgical and post-surgical findings showed that this segment was not related to the patient’s femur. the foreign segment may have belonged to the other victim of this trauma. introduction femoral shaft fracture is one of the typical bone fractures due to high energy trauma and may occur as an open fracture. some foreign materials may enter the fracture site such as sand, cloth parti...

hoffa fracture is a rare injury consisting of unicondylar tangential posterior fracture of the distal femur and only very few cases have been reported in the literature. these fractures are due to high energy trauma and conservative treatment generally yields poor results, but rigid internal fixation allows early functional rehabilitation and decreases the incidence of complications. the purpos...

Experimental injuries of cartilage and bone were produced by applying shear force to the articular surfaces of the lateral femoral condyles of six-month-old pigs under various loading conditions. The lesions were divided into two groups, 'open' or 'closed', depending on the presence of a crack on the articular surface. Each was further divided into four types according to the depth of penetrati...

A fracture mechanics approach was employed to develop a model that can predict the penetration force during quasi-static needle insertion in soft tissue. The model captures a mechanical process where the sharp needle produces a crack that is opened to accommodate the shaft of the needle. This process involves the interchange of energy between four distinct phenomena: the work done by the needle...

The size effect in the failure of a hybrid adhesive joint of a metal with a fiber-polymer composite, which has been experimentally demonstrated and analytically formulated in preceding two papers, is here investigated numerically. Cohesive finite elements with a mixed-mode fracture criterion are adopted to model the adhesive layer in the metal-composite interface. A linear tractionseparation so...

The effects of annealing on the mechanical properties of polymer blends of poly(lactic acid) (PLA) and poly(ε-caprolactone) (PCL) were investigated. The bending strength and modulus of PLA/PCL tend to increase due to crystallization of the PLA phase by annealing. The mode I fracture energy, J(in), of PLA/PCL decreases dramatically due to the suppression of the ductile deformation of the spheric...

The project aims to study tensile softening behavior of fiber reinforced concrete .Concrete is very much weak in tension but by addition of randomly oriented short crimped steel fibers will change the behavior from brittle to ductile. In the present work, the steel fibers were added at the volume fraction, being 0%, 0.5%, 1%, 1.5% to the normal strength concrete and high strength concrete. The ...

In the setting of the simplest debonding problem we give a systematic comparison of the fracture models due to Griffith and Barenblatt. We prove that the Griffith model represents an asymptotic Γ -limit of the Barenblatt model, when the ratio of the external and internal lengths increases indefinitely. We then illustrate the character of convergence by solving explicitly two sample problems wit...

fractured reservoirs contain about 85 and 90 percent of oil and gas resources respectively in iran. acomprehensive study and investigation of fractures as the main factor affecting fluid flow or perhapsbarrier seems necessary for reservoir development studies. high degrees of heterogeneity andsparseness of data have incapacitated conventional deterministic methods in fracture networkmodeling. r...