Mechanical APDL Structural Analysis Guide
! ! Non-linear prestress static analysis ! antype,static nlgeom,on! include large-deflection effects (optional) nropt,unsym! uns ...
Generate frictional sliding force via the CMROTATE command. The contact stiffness matrix is based only on the initial contact s ...
= λ Where the eigenvalues λ and {x} are output as symmetric modes to Jobname.MODESYM. The [K] matrix in the above expression is ...
Pr emultiplying by [φ]T[M] when real modes are mass normalized obtains: {y}= φ {ψ} (3.1) 3.7.6. Where to Find Other Modal An ...
3.8. Comparing Mode-Extraction Methods The basic equation solved in a typical undamped modal analysis is the classical eigenvalu ...
Disk Re- quired Memory Re- quired Eigensolver Application To find many modes (about 40+) of large models. This Medium High solve ...
Typically, the following conditions must be met for the PCG Lanczos eigensolver to be most efficient: The model would be a good ...
The number of requested modes is greater than 200. The beginning frequency input on the MODOPT command is zero (or near zero). ...
3.8.6.2. Damped Method-Real and Imaginary Parts of the Eigenvector In a damped system, the response at different nodes can be ou ...
Eigensolver Eigenvalue Eigenvector the eigenvalue. (stabil- ity) If the eigenvalue is real, the corresponding modal shape is rea ...
SNODE method (MODOPT,SNODE) SUBSP method (MODOPT,SUBSP) Mechanical APDL stores the calculated residual vectors in the Jobname. ...
3.9.2. Reusing Eigenmodes Mechanical APDL analyses that require the eigenmodes from the modal analysis can reuse the modes from ...
PCG Lanczos (MODOPT,LANPCG) Supernode method (MODOPT,SNODE) Subspace method (MODOPT,SUBSP) Unsymmetric method (MODOPT,UNSYM) QR ...
3.9.5. Enforced Motion Method for Mode-Superposition Transient and Har- monic Analyses In a mode superposition transient or harm ...
NSEL,ALL NSEL,... CM, BASE2,NODE! Define component BASE2 with selected support nodes undergoing the second enforced motion FINIS ...
Mode Selection Based on DDAM Procedure (p. 75) Zero-frequency modes are ignored when mode selection is based on a criterion (M ...
antype, MODAL, RESTART mxpand, %tab%,,, yes! Mode selection is based on user input array, and element results are ! requested so ...
3.9.6.3. Mode Selection Based on the Mode Coefficients The mode selection is performed during a modal analysis restart. It is ap ...
3.9.6.4. Mode Selection Based on DDAM Procedure The mode selection is performed during a modal analysis restart. It is applicabl ...
! procedure, the default significance ! threshold is 0.01 and element results are! requested solve finish ! Perform a DDAM spect ...
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