This paper is directed towards :nite element computation of fracture parameters in functionally graded material (FGM) assemblages of arbitrary geometry with stationary cracks. Graded :nite elements are developed where the elastic moduli are smooth functions of spatial co-ordinates which are integrated into the element sti=ness matrix. In particular, stress intensity factors for mode I and mixed...

During crack growth of real materials, the total energy released can be partitioned into elastic and dissipative terms. By analyzing material models with mechanisms for dissipating energy and tracking all energy terms during crack growth, it is proposed that computer simulations of fracture can model crack growth by a total energy balance condition. One approach for developing fracture simulati...

conclusions vacuum-assisted abdominal closure is a good technique for temporary abdominal closure. in patients who are unable to achieve fascial closure, skin closure alone is safe. results after 157 trauma laparotomies, 35 (22%) were open abdomen cases with an average injury severity score was 35. ninety-four percent of open abdomens occurred after damage-control surgery. temporary vacuum-assi...

To better understand the relationship between the nucleation and growth of defects and the local stresses and phase changes that cause them, we need both imaging and stress mapping. Here, we explore how this can be achieved by bringing together synchrotron X-ray diffraction and tomographic imaging. Conventionally, these are undertaken on separate synchrotron beamlines; however, instruments capa...

As a first step towards a new crack healing methodology for cyclic loading, this paper examines two promising crack-tip shielding mechanisms during fatigue of a microcapsule toughened epoxy. Artificial crack closure is achieved by injecting precatalyzed monomer into the crack plane to form a polymer wedge at the crack tip. The effect of wedge geometry is also considered, as dictated by crack lo...

The effects of alloy production method on microstructure and hence fatigue crack growth rate and fracture mechanism have been examined for a variety of fine-grained/high dispersoid Al-Li-Mg-Zr and Al-Li-Cu-Mg-Zr alloys. Microstructures have been assessed by scanning and transmission electron microcopy, together with electron back scattered diffraction pattern assessment. In these fine-grained/h...

Nomenclature A k , a k Fourier series coefficients, d mean difference between theoretical and experimental stress values, i square root of –1, m mapping function shape descriptor, r, θ polar coordinates in the mapping plane, s standard deviation in the difference between stress values, t distance from the crack tip, x, y Cartesian coordinates in the physical plane, z complex coordinate in the p...