José Augusto C. Martins

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SUMMARY A new formulation is presented for the three-dimensional incremental quasi-static problems with unilateral frictional contact. Under the assumptions of small rotations and small strains, a second-order cone linear complementarity problem is formulated, which consists of complementarity conditions defined by bilinear functions and second-order cone(More)
A new formulation as well as a new solution technique is proposed for an equilibrium path-following method in two-dimensional quasi-static frictional contact problems. We consider the classical Coulomb friction law as well as geometrical nonlinearity explicitly. Based on a criterion of maximum dissipation of energy, we propose a formulation as a(More)
In most current digital TV applications the user interaction takes place by pressing keys on a remote control. For simple applications this type of interaction is sufficient --- however, as interactive applications become more popular new input devices are demanded. After discussing motivating scenarios, this paper presents an architecture that offers to(More)
The pelvic floor gives support to the organs in the abdominal cavity. Using the dataset made public in (Janda et al. J. Biomech. (2003) 36(6), pp. 749-757), we have reconstructed the geometry of one of the most important parts of the pelvic floor, the levator ani, using NURB surfaces. Once the surface is triangulated, the corresponding mesh is used in a(More)
Due to the weak regeneration potential of cartilage, there is a high clinical incidence of articular joint disease, leading to a strong demand for cartilaginous tissue surrogates. The aim of this study was to evaluate a gelatin-based hydrogel for its suitability to support chondrogenic differentiation of human mesenchymal stem cells. Gelatin-based hydrogels(More)
A unified formulation and a numerical approach are presented for two-and three-dimensional incremental quasi-static problems with unilateral frictional contact. Under the assumptions of small rotations and small strains, a Second-Order Cone Linear Complementarity Problem (SOCLCP) is formulated, which consists of complementarity conditions defined by(More)
A new formulation as well as a new solution technique is proposed for an equilibrium path-following method in two-dimensional quasistatic frictional contact problems. We consider the Coulomb friction law as well as geometrical nonlinearity explicitly. Based on a criterion of maximum dissipation of energy, we propose a formulation as a mathematical program(More)
The pelvic floor gives support to the organs in the abdominal cavity. Using the dataset made public in [9] we have reconstructed the geometry of one of the most important parts of the pelvic floor, the levator ani, using NURB surfaces. Once the surface is triangulated, this mesh is used in a finite element analysis with shell elements. Based on the 3D(More)
The numerical solution of quasi-static incremental frictional contact problems involving discrete versions of two-and three-dimensional elastic solids or structures is sought with a Second Order Cone Linear Complementarity Problem (SOCLCP) formulation. The Coulomb friction cone is considered without any pyramidal approximation. Some illustrative numerical(More)