Vibration Analysis And Optimization Design Of The Drum Of The High-speed Tire Test-bed

As the vehicle speed increases, the original tire test-bed can't meet the need of the test. Automobile high-speed tire test-bed is designed. Automobile high-speed tire test-bed is mainly used to test and identify the dynamic characteristics of vehicle tires and the suspension system in high speed and provide basis for the research of the dynamic characteristics of the whole vehicle and each component of the vehicle。The drum, which is an important component of the automobile high-speed tire test-bed is the subject of this thesis. During the test of the high-speed performance of vehicles, the dynamic characteristics design of the drum will be the key step in the design of the whole automobile high-speed tire test-bed because the dynamic characteristics of the drum directly influences the result of the test. To avoid the resonance during the work, the first eigenfrequency of the drum should be increased greatly in the design of the drum. This is very important in the design of the whole drum and even the whole automobile high-speed tire test-bed. The design of the drum has two other characteristics. First, both the inner and outer side of the drum outer ring can function as the interface of the tested tire, which enables the automobile high-speed tire test-bed to test the high-speed performance of two vehicles at the same time. Secondly, the diameter of the drum is 4m. This makes both the inner and outer side of the outer ring of the drum, which contact the tested tire, truly simulate the vehicles' actual running condition.This thesis uses topology optimization theory and carries out the modal analysis and design optimization using the finite element software, Hyper Works. According to the result of topology optimization, we get three kinds of finite element models for the drum and the first eigenfrequency of the drum is greatly improved. However, these three models have their own advantages and disadvantages. For the first model, the first eigenfrequency is the lowest, but the manufacture technology is simple; for the third model, the first eigenfrequency is much higher than that of the first and the second model, but the manufacture technology is complicated. All three models can not fulfill the following conditions at the same time: first, to increase the eigenfrequency of the drum structure as much as possible; secondly, to lower the casting technological requirements as much as possible; the quality should be as light as possible. To make the structure of the drum more reasonable, we get the fourth design scheme synthesizing the former three design schemes.After the structure of the drum is determined,we optimize the size of the fourth model by OptiStruct and make the total mass of the drum decrease 18% on condition that the first eigenfrequency is not lowered. Then we carry out the model sensitivity analysis and optimal design of the revised model using ANSYS. Through model sensitivity analysis, we get more sensitive design variables and revise each design parameter reasonably. The result of the revision is that the mass of drum is reduced by 413kg on condition that the first eigenfrequency is above 90Hz. To get a more ideal design, we make full use of the merits of the finite element software ANSYS and carry out the optimal design of some more sensitive design parameters on the basis of sensitivity analysis. The result of optimization is that the total mass of the drum is decreased about 115kg on condition that the first eigenfrequency is above 90Hz. After the size optimization, model sensitivity analysis and optimal design of the best model, the first eigenfrequency of the drum is higher than 90Hz and the mass of the drum is reduced from 12.85ton to 9.99ton. From the above discussion, under the guidance of the Finite Element Theory, Topology Optimization Theory and Modal Analysis Theory, we get the more reasonable drum structure(the fourth finite element model).And the application of the finite element software-Hyper Works, Pro-E and ANSYS greatly reduces the cost and the design cycle.