Contents Chapter 11: Material Models Used in Explicit Dynamics Analysis | 11.9. Equations of State | Print page 11.9.3. Shear Modulus Shear Modulus — A shear modulus must be used when a solid or porous equation of state is selected to fully define the elastic stiffness of a material. To represent fluids, specify a small value. « 11.9.2. Bulk Modulus 11.9.4. Ideal Gas EOS »