chrono::modal::ChQuadraticEigenvalueSolverKrylovSchur Class Reference

Description

Solves the eigenvalue problem with the Krylov-Schur iterative method.

This is an efficient method to compute only the lower n modes, ex. when there are so many degreees of freedom that it would make a full solution impossible. It uses an iterative method and it exploits the sparsity of the matrices.

#include <ChEigenvalueSolver.h>

Inheritance diagram for chrono::modal::ChQuadraticEigenvalueSolverKrylovSchur:
Collaboration diagram for chrono::modal::ChQuadraticEigenvalueSolverKrylovSchur:

Public Member Functions

virtual bool Solve (const ChSparseMatrix &M, const ChSparseMatrix &R, const ChSparseMatrix &K, const ChSparseMatrix &Cq, ChMatrixDynamic< std::complex< double >> &V, ChVectorDynamic< std::complex< double >> &eig, ChVectorDynamic< double > &freq, ChVectorDynamic< double > &damping_ratio, ChEigenvalueSolverSettings settings=0) const override
 Solve the quadratic eigenvalue problem (lambda^2*M + lambda*R + K)*x = 0 s.t. More...
 

Member Function Documentation

◆ Solve()

bool chrono::modal::ChQuadraticEigenvalueSolverKrylovSchur::Solve ( const ChSparseMatrix M,
const ChSparseMatrix R,
const ChSparseMatrix K,
const ChSparseMatrix Cq,
ChMatrixDynamic< std::complex< double >> &  V,
ChVectorDynamic< std::complex< double >> &  eig,
ChVectorDynamic< double > &  freq,
ChVectorDynamic< double > &  damping_ratio,
ChEigenvalueSolverSettings  settings = 0 
) const
overridevirtual

Solve the quadratic eigenvalue problem (lambda^2*M + lambda*R + K)*x = 0 s.t.

Cq*x = 0 Returns only the first lower n_modes. If n_modes=0, it return all eigenvalues (performance warning)

Parameters
Minput M matrix
Rinput R matrix
Kinput K matrix
Cqinput Cq matrix of constraint jacobians
Voutput matrix with eigenvectors as columns, will be resized
eigoutput vector with complex eigenvalues (real part not zero if some damping), will be resized
freqoutput vector with n frequencies [Hz], as f=w/(2*PI), will be resized.
damping_ratiooutput vector with n damping rations r=damping/critical_damping.
settingsoptional: settings for the solver, or n. of desired lower eigenvalues.

Implements chrono::modal::ChQuadraticEigenvalueSolver.


The documentation for this class was generated from the following files:
  • /builds/uwsbel/chrono/src/chrono_modal/ChEigenvalueSolver.h
  • /builds/uwsbel/chrono/src/chrono_modal/ChEigenvalueSolver.cpp