NONDESTRUCTIVE MECHANICAL CONTACT IMPEDANCE AND COMPLIANCE TESTING OFRUBBER-LIKE MATERIALS

This paper is dedicated to the problems of nondestructive testing of r ubberlike materials. A new method which we call an audiosonic contact impedance evaluation is developed. It is based on mechanical contact i mpedance evaluation (MCIE) at the local contact area between a piezo a ctive sensor and specimen. A theoretical model consisting of quasistat ically loaded and consequently connected dissipative Voigt's elements is discussed and solved analytically. A resonance equation used for MC IE at the local contact area consists of two impedances: mechanical im pedance of PZT sensor and mechanical impedance of the specimen. Analyt ical results are compared with the results obtained from the simulatio n using the finite element method (FEM). Simultaneous measurements of the contact impedance and compliance associated with rubberlike materi als having different hardnesses are accomplished by the multilayered p iezo active sensor. A dynamic response obtained from the experimental sensor highly correlates with mechanical and rheological parameters.