Damped 1D OscillatorBen Heinrich2023-01-11mechaniceigenValueyes
This input file defines a single degree of freedom oscillator composed of a square mass (1mx1m) with density 1 kg/m3 in 2d (plane strain).
We constrain in x direction and connect a concentrated stiffness and damping in the y direction.
The resulting system has a mass m=1; we set k=1, thus, the (undamped) natural frequency is w_0=2*pi Hz.
Setting xi=3/5, i.e. the damping constant c=2*m*w_0*xi=2*1*1*3/5, we obtain 2 eigenvalues with
Re(lambda) = -3/5 = -0.6 and Im(lambda) = +-4/5 = +-0.8
The corresponding quadratic EVP is linearized with the quadratic eigensolver, the resulting generalized EVP is solved with the external eigensolver
(calling a Python script). The eigenvalues and eigenvectors are imported from a matrix market file in coordinate format.
-0.602massdampingstiffnessfirstCompanionyespython3 EigenSolver.py1e-9