Flexibility of approximation in pies applied for solving elastoplastic boundary problems

The paper presents the flexibility of approximation in PIES applied for solving elastoplastic boundary value problems. Three various approaches to approximation of plastic strains have been tested. The first one bases on the globally applied Lagrange polynomial. The two remaining are local: inverse distance weighting (IDW) method and approximation in different zones by locally applied Lagrange polynomials. Some examples are solved and results obtained are compared with analytical solutions. Conclusions on the effectiveness of presented approaches have been drawn

Gn blending multiple surfaces in polar coordinates

International audienceThis paper proposes a method of Gn blending multiple parametric surfaces in polar coordinates. It models the geometric continuity conditions of parametric surfaces in polar coordinates and presents a mechanism of converting a Cartesian parametric surface into its polar coordinate form. The basic idea is first to reparameterize the parametric blendees into the form of polar coordinates. Then they are blended simultaneously by a basis function in the complex domain. To extend its compatibility, we also propose a method of converting polar coordinate blending surface into N NURBS patches. One application of this technique is to fill N-sided holes. Examples are presented to show its feasibility and practicability

An improved positivity preserving odd degree-n Said-Ball boundary curves on rectangular grid using partial differential equation

This paper discusses the sufficient conditions for positivity preserving odd degree-n Said-Ball boundary curves defined on a rectangular grid.We derive a sufficient condition on boundary curves of rectangular Said-Ball patches where the lower bound ordinates are adjusted independently.To construct the boundary curves for each rectangular patch, the Said-Ball polynomial solution of fourth order PDE will be considered where its coefficients can be calculated using edge Said-Ball ordinates which fulfill the positivity preserving conditions.Graphical examples are presented using well-known test functions