Design And Optimization Of The Rubber Shock Absorber

Rubber string, a critical component in damping system, can reduce and eliminate vibrations of the vehicle body, and prevent the noise from transmission. The rubber shock absorber is widely used in bullet trains because of its good preference. The rubber shock absorber for floor is a vital damper of damping system in the vehicle body floor. At present, since the complicated structure of the rubber shock absorber and fluctuating nonlinear characteristics of the rubber material, there is no ideal model or analytic formula can accurately describe the relationship between the elastic properties and structure parameters of the rubber shock absorber yet. Thus the structural design of the rubber shock absorber has no certain method, mostly adopting empirical design and experimental correction. Also, the design of rubber shock absorber for floor are greatly influenced by the location and installation space. Therefore, it has significances to find a good method of optimizing the rubber shock absorber for developing high performance rubber shock absorber and perfecting the development system of rubber strings. The main contents are as follows:1. To find the existing limitations to the design and optimization of rubber shock absorber through consulting a large number of relevant documentation and making further study on its present situation and developing trend of rubber shock absorber design at home and abroad.2. By analyzing the shock absorption principium, rubber shock absorber can be overall seen as one degree of freedom vibration system. When rubber is chosen to be the super-elastic materials for making damper, the nonlinear property of material itself is the main factor affecting the design, thus selecting the ABAQUS to design for CAE.3. Study the basic properties of the rubber material, and then consult the relevant information about formulation of the shock absorber to determine the use of natural rubber formulations under semi-efficient vulcanizing system, that's the preparation of the required rubber; introduces the Large Deformation Theory and strain energy density function, detailing the commonly used various super elastic constitutive model and its model function; Obtained the required stress-strain data by experiments, and fitted at three different levels of 0.5, 1, then fitted error analysis, ultimately selected Ogden N3 model. Another one is verified by experimental cylindrical rubber samples, compared with the stiffness results obtained by comparative tests and simulated experiment, only to find that the constitutive model of 0.5 strain level is the best one.4. Depending on different using frequency to determine the characteristic frequency of a single damping system, and then determine the quality of the vibrating system according to the specific loading quantity, according to the damping of single degree of freedom forced vibration formula to calculate the dynamic stiffness of the shock absorber, and then select the appropriate ratio of the dynamic and static stiffness, and ultimately determine the value of static stiffness of the shock absorber. Determine the structure and size of the mode damper connecting portion and preliminarily determine the structure of the shock absorber to benefit the next step of optimization.5. Firstly, it introduces the definition of optimization, and gives rise to optimization purposes and constraints. Secondly, optimize the results in two ways. The first method is carried out by experience optimization, optimizing input values constantly, so that the results meet optimization goals. The second method is making use of the optimization module ABAQUS, optimizing calculation step through the detailed description, then optimize objects and reset the constraints. At last, it draws a conclusion: the best way is the combination of two ways, you can quickly approaching optimization goals through finite element optimization, then partial resizing; and make stiffness analysis on rubbers filled with various amounts of carbon black. Then obtained stiffness and carbon black filler volume, naturally the relationship formula of stiffness and hardness.