The isogeometric methodology has been successfully implemented in one-step inverse analysis of sheet metal stamping processes. However, these models are not capable analyzing forming processes that require severe deformation and several stages. This paper presents a multi-step to enhance the precision predictions initial blank, strain distributions, drawability formed parts. deals with minimiza...

The effect of knot modifications on the shape of B-spline and NURBS curves is discussed in this paper. Theoretical results include the description of the path of curve points, obtained by the modification of a knot value, and the examination of the one-parameter family of curves. It is shown that this family has an envelope which is a lower order B-spline or NURBS curve. Applying these results ...

For rendering purposes trimmed NURBS surfaces have to be converted into a polygonal representation. In order to fulfill the high quality visualization demands posed by various design and quality control applications, current NURBS rendering methods require a careful preparation of the converted models which often needs manual user intervention. This preprocessing step prevents the user from int...

Owning to the high-speed feed rate and ultra spindle speed have been used in modern machine tools, the tool-path generation plays a key role in the successful application of a High-Speed Machining (HSM) system. Because of its importance in both high-speed machining and tool-path generation, approximating a contour by NURBS format is a potential function in CAD/CAM/CNC systems. It is much more c...

This article presents an effective computational approach that incorporates a quasi-brittle damage model into the isogeometric analysis of plates made functionally graded materials. The plate kinematics is represented by third-order shear deformation theory for higher accuracy. A coupling nonlocal equivalent strain field introduced on neutral surface to control softening behavior. utilization i...

We develop a dynamic, free-form surface model which is useful for representing a broad class of objects with symmetries and topological variability. The new model is based upon swung NURBS surfaces, and it inherits their desirable cross-sectional design properties. It melds these geometric features with the demonstrated conveniences of surface design within a physics-based framework. We demonst...

The determination of molecular interaction forces, e.g., van der Waals force, between macroscopic bodies is of fundamental importance for understanding sintering, adhesion and fracture processes. In this paper, we develop an accurate, general procedure for van der Waals force calculation. This approach extends a surface formulation that converts a six-dimensional (6D) volume integral into a 4D ...

A surface extraction algorithm with NURBS has been developed for the mesh generation from the scattered data after a cell-based simulation. The triangulation of a surface is initiated with a step of describing the geometry along the polygonal boundary with multiple points. In this work, an NURBS surface can be generated with scattered data for each polygonal surface by employing a multilevel B-...

This paper considers the dynamic analysis of a spatially curved Bernoulli-Euler beam subjected to moving load. The isogeometric approach is used for spatial discretization weak form equation motion. Both reference geometry and solution space are represented using same NURBS basis functions that guarantee an accurate description centerline. time integration done by explicit technique. presented ...

the isogeometric analysis is increasingly used in various engineering problems. it is based on non-uniform rational b-splines (nurbs) basis function applied for the solution field approximation and the geometry description. one of the major concerns with this method is finding an efficient approach to impose essential boundary conditions, especially for inhomogeneous boundaries. the main contri...