in this study, an extended stress-based forming limit diagram (fld) for prediction of necking based on the marciniak and kucznski (m-k) model is represented and applied in tube hydroforming. the bulge forming of a straight tube is simulated by finite element method and verified with published experimental data. this adaptive simulation technique is based on the ability to detect the onset and g...

Nowadays, many industrial applications require online systems that combine several processing techniques in order to offer solutions to complex problems as the case of detection and classification of multiple faults in induction motors. In this work, a novel digital structure to implement the empirical mode decomposition (EMD) for processing nonstationary and nonlinear signals using the full sp...

We present an h–adaptive version of the spacetime–discontinuous Galerkin (SDG) finite element method for linearized elastodynamics (Abedi et al., 2005) that is particularly well suited to multiscale simulations and to problems involving shocks. The adaptive version inherits key properties of the basic SDG formulation, including element-wise balance of linear and angular momentum, complexity tha...

Finite element simulations in computer graphics are typically based on tetrahedral or hexahedral elements, which enables simple and efficient implementations, but in turn requires complicated remeshing in case of topological changes or adaptive refinement. We propose a flexible finite element method for arbitrary polyhedral elements, thereby effectively avoiding the need for remeshing. Our poly...

In this article we develop convergence theory for a class of goal-oriented adaptive finite element algorithms for second order semilinear elliptic equations. We first introduce several approximate dual problems, and briefly discuss the target problem class. We then review some standard facts concerning conforming finite element discretization and error-estimate-driven adaptive finite element me...

This paper presents the design and implementation of adaptive feedback active noise control system (ANC) for head phone applications. Active Noise Control is a technique of acoustic noise reduction using a secondary source of sound which produces ”antinoise” to cancel the primary noise. In this paper, narrow band single channel feedback ANC for headsets application is focused upon. The filter w...

We develop an adaptive finite element method (AFEM) using piecewise linears on a sequence of triangulations obtained by adaptive √ 3 refinement. The motivation to consider √ 3 refinement stems from the fact that it is a slower topological refinement than the usual red or red-green refinement, and that it alternates the orientation of the refined triangles, such that certain features or singular...

In this paper, we propose and analyze a linear time stepping finite element method for abstract second order linear evolution problems. For such methods, we derive optimal order a posteriori error estimates and sharp a posteriori nodal error estimates using the energy approach and the duality argument. Based on these estimates, we further design an adaptive time stepping strategy for the previo...

The analytical treatment of linear intracavity phase aberrations and their compensation by an appropriately configured intracavity adaptive optic element is presented in this paper. The approximate geometrical treatment of the effects of intracavity phase aberrations is first treated, followed by a complete exact diffraction integral formulation of the adaptive compensation of linear phase-tilt...