We know that the velocity gradient L = F'F-1 [ F ' is the time derivative of F ]
Using multiplicative decomposition, F =FeFp
we have , L = F'eFe -1 + Fe F'p Fp -1 Fe -1 = Le + Fe Lp Fe -1
Each of the above velocity gradients ( Le & Fe Lp Fe-1) could be decomposed into corresponding stretch and spin tensors as
Le = De + We
Fe Lp Fe-1 = Dp + Wp
Questions :
1) How do we intuitively understand We , Dp and Wp
2) Can we say that skew-symmetric part of Lp alone is ZERO , since there is no rotation involved in the intermediate configuration ?