A four-node square element undergoes large displacement and rotation in the XY plane, as shown in the figure.
The node initially at the origin is moved to (1, 1 - sinπ/4) and the element is rotated by 45°. Calculate the deformation gradient.
Compute the Lagrangian strains and demonstrate that no strain occurs during rigid-body motion.
![297_Figure 03.gif](https://secure.tutorsglobe.com/CMSImages/297_Figure 03.gif)