This article proposes a rubber suspension bushing model considering amplitude dependence as a useful tool at the initial design phase. The purpose of this study is not to express physical phenomena accurately and in detail and to explore the truth academically, but to provide a useful design method for initial design phase.
Experiments were carried out to verify several dynamic characteristics of rubber bushings under vibration up to a frequency of 100 Hz, which is an important frequency range when designing ride comfort performance. When dynamic characteristic theory and the geometrical properties of the force-displacement characteristic curve were considered using these dynamic characteristics as assumptions, an equation was derived that is capable of calculating the dynamic stiffness under an arbitrary amplitude by identifying only two general design parameters (dynamic stiffness and loss factor) under a reference amplitude. The rubber suspension bushing model was then constructed by transforming this equation. Two verifications were carried out to confirm that the model is capable of reproducing measured bushing characteristics. Previous models consist of a large amplitude stiffness component and an artificially created friction component, and must be identified using three unknown values. In contrast, the proposed model only consists of a function derived theoretically from the above assumptions.
Consequently, this model can be identified using the two unknown values described above, which are general design parameters used by suspension engineers in everyday design work.
