Vibration Isolation Design And Analysis Of Large-Scale Experimental Equipment In Civil Engineering

Nowadays,with the rapidly development of seismic design and experimental technologies in civil engineering, the performance requirements for the experimental equipment are enhanced. More and more multi-function test machines and shaking tables are used in laboratory and the loading capacity is increasingly large, which in return cause complex vibration problems. Those problems have gained wide attention and improve the difficulties for vibration isolation design. Vibration isolation and energy dissipation technology is an important method to solve the problems of vibration control, which is widely used in the areas like construction and manufacturing. However, it is comparatively rare in experimental equipment cases. In this paper, detailed vibration design for a large-scale multi-function test machine and a 3-axial shaking table was conducted. Besides, vibration of the structure around was evaluated and the vibration isolation design method was summarized and concluded. The main contents and conclusions are as follows.(1) The object of this study is a large multi-function test machine, which is used to conduct a vibration isolation design based on the method summarized from industrial equipment. Besides, the problem of collision in machine is also considered in the process of evaluating the effect of isolation, which is achieved by simplified model analysis.(2) Since the case of vibration isolation design for large test machine is relatively rare, a detailed vibration isolation design, including the selection and arrangement, is conducted. In this study, the dynamic response of the machine is obtained through finite element analysis in three conditions, which verified the validity and the security of the design. In addition, the seismic response of the machine is also acquired, which shows that the system is not only well-isolated, but possess a good earthquake resistant behavior.(3) Based on air spring, a detailed vibration isolation design for a 3-axial shaking table is proposed. The dynamic response of the table and the base under it is acquired through simulating different working conditions like beating wave, sweeping frequency, resonance and earthquake motion. The result shows that the air spring has a significant effect on vibration isolation, even if it is on the worst situation. This study provides experiences on isolating the lower frequency.(4) The vibration originated from machine can cause second vibration on the structural around it. However, the serviceability of the structure is an important target for the vibration isolation design. The finite element model of the structure around the test machine are established to analyze the response and the result shows that the impact of vibration is small after effective design, which satisfy the standard of our country.