SAE J 3130:2023-12-20

This SAE Recommended Practice describes a laboratory test procedure for measuring the composite loss factor and bending stiffness properties of a system consisting of a damping material bonded to a vibrating bar which is excited at the center. The bar could be a steel, aluminum, glass, or other metal or composite bar that would be used in ground vehicles, marine products, and aircraft. The damping materials could be homogeneous, nonhomogeneous, a combination of homogeneous and nonhomogeneous, used in conjunction without or with an inelastic material (such as aluminum foil) in an extensional layer or a constrained layer configuration. The damping material could be a heat bondable material, adhesive backed sheet material, sprayable coating material, or other kinds of viscoelastic materials.