Synthesize FRF from shapes with unknown modal mass. Shape coefficients, damping, natural frequency known. Modal participation factors, (combination of modal mass and reference coordinate trace shape.coefficients unknown).
NOTE: This version works only for real mode shapes.
fsyn=frf_fit(f,st,flim,type)
This function synthesizes FRFs for real shapes. It is assumed that modal mass and/or shape coefficients for reference coordinates (the modal participation factors) are unknown. The modal participation factors are first solved for, and then the FRFs are synthesized.
F – imat_fn containing FRFs that will be synthesized
ST – imat_shp used to synthesize FRFs. Shape must be “real” (not complex)
FLIM - 1 x 2 matrix containing lower and upper frequency bounds of synthesis.
TYPE – ‘both’ or ‘imag’
‘both’ uses both real and imaginary
parts of FRF to solve for modal participation factors.
‘imag’ uses imaginary part
of FRF to solve for modal participation factors
FSYN - imat_fn containing synthesized FRFs
>> [fsyn]=frf_fit(f,st,[10 100],’imag’)
>> [fsyn]=frf_fit(f,st,[5 1000],’both’)
imat_fn, imat_shp, ind_frf_fit, ind_frf_fit_c