Subspace Projection (Dassault Systemes - PLM Solutions/SIMULIA/ABAQUS)

Hab dazu was gefunden...

The *STEADY STATE DYNAMICS procedure is used to calculate the steady state response of a system to harmonic loading. Three different formulations of the procedure are available in Abaqus; mode based, direct solution and subspace based. Each is a linear perturbation procedure that calculates the system's linearized response at a series of different frequencies. The salient features of each formulation are outlined below.

Mode Based
Uses a modal superposition approach in which the equations of motion are written in terms of generalized mass and coordinates by projecting them onto the eigenmodes.
Is the least computationally expensive of the three types.
Allows no frequency dependent material properties or unsymmetry in the stiffness matrix.

Direct Solution
Uses a direct solution approach in which the unaltered equations of motion are solved in terms of the physical degrees of freedom.
Is the most computationally expensive of the three types.
Is the most accurate approach when material properties and/or damping are strongly frequency dependent

Subspace Based
Uses a direct solution of the equations of motion that have been projected onto a subspace of the eigenmodes. The eigenmodes may not be orthogonal to the damping and stiffness matrices if these matrices are frequency dependent. As a result, they are not diagonalized upon projection and a direct solution is required.
Is less computationally expensive than the direct method, but more expensive than the mode based method.
Offers a cheaper alternative to the direct method when frequency dependent material damping and viscoelastic effects are present but not significant.
__________________________________________________________________________________________________________________________________________

Mit Mode Base ist man anscheinend am schnellsten.
Sowie ich das jetzt verstanden habe ist die Subspace Projection eine Mischung aus Mode Base und Direk Methode.
Da wird die direkte Lösung auf die Eigenmoden verwendet und nicht auf allen Freitheitsgeraden.
Die Modalanalyse vor der SSD-Subspace reduziert also das Aufwand. Falls meine Vorstellung nicht stimmt, bitte korrigieren ))

Lg Alican

Eine Antwort auf diesen Beitrag verfassen (mit Zitat/Zitat des Beitrags) IP