We present a way of constructing multi-time-step monolithic coupling methods for elastodynamics. The governing equations for constrained multiple subdomains are written in dual Schur form and enforce the continuity of velocities at system time levels. The resulting equations will be in the form of differential-algebraic equations. To crystallize the ideas we shall employ Newmark family of time-...

Comparison of 1719 differential GPS measurements with a 1 m LiDAR DEM covering West Seattle shows that DEM elevation errors range from –4.88 m to +3.32 m. The errors are spatially correlated with a semivariogram range of 125 m, an unclustered mean of –0.11 m, and an unclustered standard deviation of ±0.75 m. Although there are statistically significant correlations between elevation error and e...

This work aims at simulating the time response of a structure damped by viscoelastic materials. The structure is discretised by finite elements and a 4-parameter fractional derivative model is used to describe the frequency-dependency of the mechanical properties of the viscoelastic material. The proposed approach combines a classical Newmark time-integration scheme to solve the semi-discretise...

In this article, we devote ourselves to establishing a natural boundary element (NBE) method for the Sobolev equation in the 2D unbounded domain. To this end, we first constitute the time semi-discretized super-convergence format for the Sobolev equation by means of the Newmark method. Then, using the principle of natural boundary reduction, we establish a fully discretized NBE format based on ...

The problem of transient dynamics of highly flexible three-dimensional space-curved beams, undergoing large rotations and stretches, is treated. The case of conservative force loading, which may also lead to configuration-dependent moments on the beam, is considered. Using the three parameters associated with a conformal rotation vector representation of finite rotations, a well-defined Hamilto...

A simulation of the NC-shape grinding process of free formed surfaces is considered. A central issue in the simulation is the numerical solution of dynamic Signorini problems. Here, space adaptive techniques for such problems are discussed. The Newmark method in time and low order finite elements in space are used for discretisation. For the global discretisation error in space, an a posteriori...

The aim of this work is to increase the instability of the marching-on-in-time (MOT) method that is used in the analysis of wide-band electromagnetic pulse scattering from structures made of thin wires. The stability problem has been identified with the advent of the MOT method in 1991, and although several improvements have been suggested to overcome this difficulty no exact solution has been ...

A time-accurate procedure to model fluid/structure interactions of helicopter blades is presented. The Navier-Stokes equations in conjunction with the one-equation SpalartAllmaras turbulence model are used to compute the flow. Structural dynamics is modeled using the modal equations. The aerodynamic and structural dynamic equations are coupled time-accurately using the linear acceleration metho...

Recently, multi-time stepping methods have become very popular among scientist due to their high stability in problems with critical conditions. One important shortcoming of these methods backs to their high amount of uncontrolled amplitude decay. This study proposes a new multi-time stepping method in which the time step is split into two sub-steps. The first sub-step is solved using the well-...