Abstract— This paper models (large) deformations of shelllike objects under the grasping of a robot hand. Classical nonlinear theory of thin shells [21, pp. 186-194] is generalized to shells with arbitrary parametric middle surfaces, using a method introduced in our earlier work [13]. An experimental study demonstrates higher modeling accuracy using the nonlinear elasticity theory than its linear counterpart. Given that many deformable objects undergo sizable shape changes when they are grasped, our result supports the application of nonlinear elasticity theory in the future design of grasp strategies for this type of objects.