Deadline for abstract submission: March 3, 2008

We enhanced a bi-layer fiber-matrix microstructural arterial model with softening and analyzed the artery inflation under the internal pressure. Numerical simulations lead to the following three findings. Firstly, it is found that the fiber strength dominates the strength of the media layer. Secondly, it is found that the strength of the media layer dominates the overall arterial strength and plays the crucial role in the load-bearing capacity of arteries. Thirdly, it is found that residual stresses can increase the overall arterial strength significantly. The pre-existing compression in arteries delays the onset of rupture like the pre-existing compression in the pre-stressed concrete delays the crack opening.

  A new failure criterion has been formulated for fiber composite materials.  It is the anisotropic counterpart of a recently derived isotropic criterion.  The targeted applications are for carbon fiber, polymeric matrix (or equivalent) types of materials.

Many studies on the thin film/substrate structure and its failure mechanism were reported in recent years. The direct experimental results of thin film/substrate structure by scanning electron microscopy (SEM) presents an intriguing problem:there exists a buckling failure mechanism at the lateral edge of metal film under pure bending. The qualitative theoretical analysis has been done on such buckling failure of thin film/substrate structure.

In a recent discussion it was suggested that it would be useful to perform tension tests on collagen fibrils. We have developed a MEMS-based experimental procedure that is capable of applying very large strains to individual collagen fibrils. The attached paper presents illustrative data; an upcoming paper will present much more data that illustrates the rich behavior of these fibrils during loading and unloading tests.

Here is a Lectureship in Solid Mechanics available in the Engineering Science Department at Oxford posted by Prof.Alan Cocks.