The symmetric interior penalty discontinuous Galerkin finite element method is presented for the numerical discretization of the second-order wave equation. The resulting stiffness matrix is symmetric positive definite and the mass matrix is essentially diagonal; hence, the method is inherently parallel and leads to fully explicit time integration when coupled with an explicit timestepping sche...

The numaical simulation of chemically reacting flows is a topic that has attracted a great deal of cunent research At the heart of numerical reactive flow simulations are large sets of coupled, nonlinear Partial Differential Equations (PDEs) Due to the stiffness that is usually present,, explicit time differencing schemes are not used despite theil inherent simplicity and efficiency on parallel...

A 3D finite element (FE) analysis technique using ABAQUS is chosen to explore the dynamic behavior of a beam under impact load. A beam, for which the impact dynamic test was conducted by Kishi (2004), is selected to develop a solid element FE model. FE analyses were performed implementing ABAQUS Explicit (2004) programming tool to predict the dynamic responses under the pressure amplitude intro...

This paper presents a method for solving the linear semi-implicit immersed boundary equations which avoids the severe time step restriction presented by explicittime methods. The Lagrangian variables are eliminated via a Schur complement to form a purely Eulerian saddle point system, which is preconditioned by a projection operator and then solved by a Krylov subspace method. From the viewpoint...

The numerical simulation of chemically reacting flows is a topic that has attracted a great deal of current research. At the heart of numerical reactive flow simulations are large sets of coupled, nonlinear partial differential equations (PDEs). Due to the stiffness that is usually present, explicit time differencing schemes are not used despite their inherent simplicity and efficiency on paral...

Unstructured multigrid techniques for relieving the stiffness associated with high-Reynolds number viscous flow simulations on extremely stretched grids are investigated. One approach consists of employing a semi-coarsening or directional-coarsening technique, based on the directions of strong coupling within the mesh, in order to construct more optimal coarse grid levels. An alternate approach...

We propose an efficient numerical algorithm for computing deformations of “very” soft tissues (such as the brain, liver, kidney etc.), with applications to real time surgical simulation. The algorithm is based on the finite element method using the Total Lagrangian formulation, where stresses and strains are measured with respect to the original configuration. This choice allows for pre-computi...

In the mirror milling process of large thin-walled parts, maintaining a constant supporting force is crucial for improving the workpiece local stiffness to suppress vibration. Aiming at the flexible characteristics of large thin-walled parts, this work presents a position-based force explicit control strategy based on online trajectory prediction. An online trajectory pre-modification force con...

Bearing stiffness, as one of the most important service characteristics for ball bearing, plays a crucial role in bearing design and rotor dynamic analysis. To rapidly accurately calculate stiffness matrix under arbitrary load conditions, 5-DOF analytical model analysis has been established by ball–raceway contact analysis, implicit/explicit differential method, operations. The validated compar...

We focus on a class of models used for representing the dynamics between a discrete set of probabilistic events in a continuous-time setting. The proposed framework offers tractable learning and inference procedures and provides compact state representations for processes which exhibit variable delays between events. The approach is applied to a heart sound labeling task that exhibits long-rang...