New Computer Model Could Lead to Safer Stents

A team of researchers in the MIT-Harvard Division of Health Sciences and Technology has developed a computer model that explains why drugs used in stents can accumulate in the arteries and cause blood clots.

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Original source : http://www.hpcwire.com/industry/academia/New-Compu...

Active and passive behaviors of soft tissues: Pelvic floor muscles

A new active-contraction visco-elastic numerical model of the pelvic floor (skeletal) muscle is presented. Our model includes all elements that represent the muscle constitutive behavior, contraction and relaxation. In contrast with the previous models, the activation function can be null. The complete equations are shown and exactly linearized. Small verification and validation tests are performed and the pelvis is modeled using the data from the intra-abdominal pressure tests. Copyright © 2009 John Wiley & Sons, Ltd.

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Original source : http://dx.doi.org/10.1002%2Fcnm.1351...

A stress-return algorithm for nonlocal constitutive models of softening materials

We develop a fully implicit stress-return algorithm for a wide range of nonlocal inelastic models (of integral type) with coupling among integration points. Two examples of nonlocal models are presented, which combine plasticity with either damage or breakage. Using these models, we emphasize the need for a versatile integration scheme for nonlocal incremental constitutive equations. Furthermore, these models are used to demonstrate the importance of adequately selecting the way constitutive equations for softening materials are regularized. The stress update process requires the construction of a nonlocal constitutive matrix: we highlight and take advantage of its sparsity. Numerical solutions to relevant structural and geomechanical boundary value problems are used to demonstrate the performance of the proposed approach. Copyright © 2009 John Wiley & Sons, Ltd.

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Original source : http://dx.doi.org/10.1002%2Fnme.2790...