Compressive strength measurements were conducted on 32 macroporous biphasic calcium phosphate (MBCP) samples to evaluate the influences and interactions of five synthesis factors: chemical composition, percentage of macropores, mean size of macropores, isostatic compaction pressure, and sintering temperature. These parameters were varied simultaneously between two limit levels. Experiments used a factorial design method (FDM) allowing optimization of the number of samples as well as statistical analysis of results. FDM showed that compressive strength, in a defined experimental area, can be described by a first-order polynomial equation in which the percentage of macroporosity and sintering temperature are the major influences. This study leads up to an isoresponse line diagram that will allow the manufacture of some classes of MBCP with fitted compressive strength.

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International audienceCircular-fronted cracks in round bars subject to tension, bending and twisting are considered. Numerical expressions are given allowing the calculation of stress intensity factors $K_I$, $K_{II}$, $K_{III}$ at every point on the crack front for a wide range of crack geometries. Comparisons are made with analytical, experimental and numerical results available in the literature. Crack shapes satisfying the iso-$K_I$ criterion are also determined, making it possible to investigate the problem of crack growth behaviour under tensile or bending fatigue loads

International audienceInternal stresses due to anisotropic thermal and plastic properties were investigated in a rolled Zirconium-alpha. The thermal stresses induced by a cooling process were predicted using a self-consistent model and compared with experimental results obtained by X-ray diffraction. The study of the elastoplastic response during uniaxial loading was performed along the rolling and the transverse direction of the sheet. considering the influence of the texture and the thermal stresses on the mechanical behaviour. We used an elastoplastic self-consistent formulation and the predicted results are compared with mechanical tests. The role of twinning and slip on the development of internal stresses is also discussed

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