Strain compatibility equation in non-linear solid mechanics!!!
We have six strain compatibility equations, which are obtained from strain-displacement relations by making an assumptions 'small strains'. Strain compatibility equations ensure a single valued and continuous displacemnet filed. These equations are used in stress based approach.
Now my queries are as following.
 Do we have strain compatibility equations for non-linear strain-displacement relations?
 Do we follow stress based approach in non-linear solid mechanics.
For me it looks like it is difficult (may not be possible also) derive strain compatibility equations in nonlinear solid mechanics.
I request that somebody may through light on the above by giving main focus on 'Strain compatibility equations in nonlinear solid mechanics'
Thanks in advance,
- R. Chennamsetti.