Viscoelastic materials like solid propellant grains exhibit material properties, which are timedependent and incompressible in nature. The displacement based finite elements fails to solve structural problem having incompressible materials. The basic reason is Poissons ratio approaches 0.5 for such materials. Which makes the constitutive relation between stress and strain very stiff there by the stiffness matrix becomes very stiff which yields very poor displacement results and predicted stresses and strains are unreliable. This phenomenon is known as volumetric locking. To overcome this...