Calculate back expansion matrix based on FEM shapes
TAMOUT = shp2TAMexp(SG,TAM,NODES)
SHP2TAMEXP uses the SEREP method to create a back expansion matrix for a TAM. The back-expansion matrix is calculated using the below equation, where OSET are unmeasured DOF in NODES. More shapes lead to better estimates of the TAM.
TAM.constraint = sg{TAM.oset}*pinv(sg{TAM.aset})
SG is an imat_shp containing the mode shapes to use to create the back expansion matrix.
TAM is a strcuture containing the input TAM matrix. At minimum it must contain a .aset field, which contains the ASET degrees of freedom as an imat_ctrace.
NODES is a vector containing the nodes in the Test Display Model that are also part of the analysis shapes SG.
TAMOUT is a structure containing the estimated TAM back-expansion matrix. It contains at minimum the fields:
.aset | Modal coordinate DOF (inputs to the back expansion) |
.oset | Back-expanded DOF |
.constraint | Back expansion matrix |