What is the basic difference between shell, membrane and plate?

 Shell :             subjected to axial force and bending momen.Membrane

 Membrane:   sustain transverse loading using inplane stresses.

 plates:            sustain loading using bending stresses. 

Membrane and Plates have basic differences in structural behavior. Membrane sustain transverse loading using in plane stresses. While plates sustain loading using bending stresses. 1-D analogous examples are difference between a thread/cable and beam.

If the bending stiffness of the plate is reduced to zero, it will act like a membrane with due consideration of boundary conditions.

1-Shell : subjected to axial force and bending moment

2-Membrane: subjected to axial force

3- Plate : subjected to  bending moment