In this article, stress analysis and energy estimation during cold-roll forming of symmetrical channel sections have been discussed. Geometry of sheet strip is pre-estimated by a shape function. Then longitudinal, transversal and shear strains have been calculated. Using both the Levy-Mises and the Prandtl Reuss equations, and also considering the Bauschinger effect, stress distributions have b...

Shoulder geometry of tool plays an important role in friction-stir welding because it controls thermal interactions and heat generation. This work is proposed and developed a coupled rigid-viscoplastic numerical modeling based on computational fluid dynamics and finite element calculations aiming to understand these interactions. Model solves mass conservation, momentum, and energy equations in...

Many applications are dealing with geometric data that are affected by uncertainty. It is important to analyze, visualize, and understand the properties of uncertain geometry. We present a methodology to model uncertain geometry based on multi-variate normal distributions. In addition, we propose a visualization technique to represent a hull for uncertain geometry capturing a user-defined perce...

Several image processing operators are combined with various computational geometry techniques, in order to quickly generate discrete surface representations of arteries from medical images. These surface representations are then used to generate nite element meshes suitable for CFD calculations of blood ow in arteries.

Arrangements of lines in the plane and algorithms for computing extreme features of arrangements are a major topic in computational geometry. Theoretical bounds on the size of these features are also of great interest. Heilbronn’s triangle problem is one of the famous problems in discrete geometry. In this paper we show a duality between extreme (small) face problems in line arrangements (bound...

Given an arbitrary polygon P with holes, we construct a polytopal complex analogous to the associahedron based on convex diagonalizations of P . This polytopal complex is shown to be contractible, and a geometric realization is provided based on the theory of secondary polytopes. We then reformulate a combinatorial deformation theory and present an open problem based on visibility which is a cl...

We propose a new technique to implement solid wall boundary conditions for steady two-dimensional Euler equations for problems in curved geometries. The technique is to be used with high-order methods on unstructured, straight-sided element meshes. By modeling flow around a physical rather than computational geometry, significant improvement in quality of the solution is achieved. The technique...

This paper describes the design and the implementation of the three-dimensional trian-gulation package 1 of the Computational Geometric Algorithms Library Cgal 2. We focus on representation issues and especially insist on how the cases of degenerate dimensions are treated. The algorithmic issues are not examined in this short paper.