Influence of hardness on mechanical properties of elastomers
Treść / Zawartość
In this paper, elastomers with different hardness factors were examined to evaluate the influence of the hardness on their mechanical properties. The following hardness numbers, measured in Shore A hardness scale, were investigated: 40; 60; 70 and 90°. Basic mechanical tests i.e. axial tension and axial compression have been performed in order to calculate elastic properties and stress values corresponding to the fixed strains: epsilon = 0.2; 0.3 and 0.5. The sigma (epsilon) dependences from the tension and compression tests are nonlinear and have different shapes. The tension plot can be described by a convex parabola, while the compression curve can be approximated by a concave one. dynamic load tests with loading freąuencies 0.01; 0.1; 1.0 and 3,OHz were performed in order to determine the hysteresis loop and to obtain force and displacement dependences in time. From those results the following factors were calculated: relative damping coefficient and mechanical loss angle, as well as their dependence on load frequencies. The influence of hardness on both in-phase and out-of-phase components of normal modulus were investigated. The sensitivity of the examined elastomers to the loading rate was also investigated.
Bibliogr. 4 poz., rys.
-  Pekalak, M., Radkowski, S., Rubber elastic elements (in Polish), PWN, p. 143, 1989.
-  Osinski, Z., Clutches and breakes (in Polish), PWN, Warsaw 1985.
-  Krawczuk, A. S., Majboroda, V. J., Uzuncew, U. S., Mechanics of polymer and composite materials (in Polish), Science, Moscow 1985.
-  Multi-author work. Rubber. Engineering and technical guide. (in Polish) , WNT, Warsaw 1981.