【作者】 张健红；

【导师】 左春柽；

【作者基本信息】 吉林大学 ， 机械设计及理论， 2007， 博士

【摘要】 本文针对一汽建设高品质重型商用车集成开发平台的需要,在全面综述和分析汽车安全实验及模拟研究现状的基础上,对摆锤碰撞过程仿真及整机虚拟装配及实车碰撞等进行了研究。论文基于矢量网络法和轴承间隙模型,用C++Builder开发了机械多体系统动力学仿真程序,对摆锤式汽车碰撞试验机、双杆复摆系统和曲柄滑块系统等进行了仿真,并将仿真结果与ADAMS结果作了对比,从而验证了软件的有效性和通用性。研究表明矢量网络法是研究动态机械系统仿真的一个十分有效的方法。论文建立了工字钢的零件库,提高了试验机的设计效率。对摆锤装置、脱钩保险装置和试验机框架进行了虚拟装配,通过数字化虚拟设计验证了工作原理。论文还建立了驾驶室正面摆锤碰撞试验的有限元模型,对驾驶室摆锤碰撞试验进行了虚拟仿真,用数字化形式代替的实物样机试验,可减少实车碰撞试验的次数,缩短新车型的开发周期,降低设计开发成本。设计并制造了一种商用车驾驶室正面摆锤碰撞试验机,具有结构先进,操作简便,维护方便等优点。根据碰撞试验结果分析对新车型驾驶室的安全设计提出了改进意见本文的研究方法和研究成果对驾驶室正面摆锤碰撞试验机结构的改进、优化和商用车驾驶室碰撞安全法规的制定以及基于耐撞性的车身结构优化、建立第3代虚拟样车和整车耐撞性虚拟试验都具有一定的参考价值。更多还原

【Abstract】 In order to improve the safety capability of vehicle, the developed countries such as America and Europe have established safety regulations. Through obliged execution of these regulations, the producer will improve the safety capability of their product feasibly. From 1990’s, China has established safety standard and regulations for cars and bus. But there isn’t a standard regulation for intensity of heavy truck cab. In recent years, the application of cab design technique has been highly regarded and design methods are abundant with the developing of automobile industry. Cab passive safety control technique involves the research on structure crash characteristics and occupant restraints systems. To study on cab occupant safety involves enlarging cab intension, installing 3-point belts, improving seat system and softening inner adorns. To permit ECE R29 regulation, the absorbing methods of cab frontal crash structure have been studied to ensure the occupants survival space after crash. Compatibility in frontal crashes have been studied to improve frontal structure design and avoid the car cross-in. FAW Research Center have spent lots of money on commercial vehicle body and design two platform cab which were J5 and J6.Abundant experiences have been accumulated in cab structure and model design. But some know-how in theoretical study and simulation technique have no advantages according to foreign company. It is important to study and produce advanced positive bob impact test of commercial vehicle cab.This paper has summarized the automobile safety experiments and analyzed the current study situations of internal and external, designed the bob system, simulated the impact process, installed the simulated model of the whole machine and analyzed the finite element modeling based on the requirement of building high quality heavy commercial vehicle platform of FAW and the 863 project. The shortcoming of repeatedly experiment in traditional design has been conquered. By using computer design, the positive bob impact test of commercial vehicle cab meets the requirement in its first trial run.The positive bob impact test of commercial vehicle cab was developed in this paper which was the first machine meeting the ECE regulations in China. The computer modeling, controlling and testing software were developed in this paper. The test machine has simple structure, high automation and could be operated convenient.This paper introduced the structure and theory of the positive bob impact test of commercial vehicle cab which was used in FAW. The unhook structure, bob swing angle and system mass center had been designed and calculated accurately. It could made frontal impact and side impact to the cab-over-engine truck which maximum mass was 1000kg..Based on vector network method, the bob vector network model was made in this paper. This paper also described the dynamic simulation study and the calculation of the moving parameter of the bob. Though the parameter, we could know the test’s initial condition. The simulation results could guide the design and experiment of the positive bob impact test of commercial vehicle cab. Study in this paper declared that the vector network method was effective in simulating mechanical systems. The advantages were as follows: its formulized procedure make it easily executed and inquired on computer .The application of vector network on this positive bob impact test supplied a feasible method for adjusting the machine before experiment and avoiding unnecessary waste.Based on the vector network method, the relationship between graph theory and vector network had been studied. Vector mechanics method based on graph theory concluded all kinds of mathematical equation on modeling mechanical system. A dynamic simulation program of mechanical multibody system was developed in this paper. It was applied to simulate the twin-bar compound pendulum mechanism and slider-crank mechanism. Compared with the ADAMS software, the results show the feasibility and commonly of the program of this paper.Based on bearing clearances dynamics model, the equation of different operating model was deduced and applied for the simulation of positive bob impact test. To test the validity of the model, the result was compared with that of the situation without the consideration of the bearing clearance and that of experiment. And that proved that the simulation result based on bearing clearances model was more close to the experimental result. The simulation result of bob system based on clearances model was compared with that of the situation without the consideration of the bearing clearance. These compared with the result of experiment showed the bearing model based on non-lubricating had more advantages than that based on lubricating. The result of the former was more accurate than the later. The bearing clearances model which this paper discusses can be used to other dynamic simulation of mechanical systems.The simulation of the impact test had accumulated experiences for real vehicle impact. Although the real vehicle impact experiment was the final way to evaluate the passive security characteristics, its costs was high and design period was too long. It couldn’t been done in the early period of design. This paper simulated non-linear impact problem with a few cells on common PC computer and spent a little time. The problem that this kind of question should been solved on work-station had been conquered in this paper. A feasible method had been found to simulate positive bob impact experiment of cab. That would guide the vehicle early design for automobile work after the truck impact regulation was executed. Based on reasonable simplify, the finite element model of cab positive bob impact experiment was built. According to the problem of big deformation and displacement, a dynamic simulation had made on the positive bob impact experiment of cab. This paper studied the rules of deformation, stress and displacement of cab which could guide the safety design. Compared with the real impact experiment, the simulate method was certificated to be correctly, reliability and feasibility. By computer simulation of the positive bob impact experiment, the security intension could be evaluated and the cab design could be improved. It has the realistic meaning for shortening the new vehicle into market time and lower the costs.The parts storage of steelⅠhad been established. It would raising the design efficiency of positive bob impact test of commercial vehicle cab. The bob system, unhook device and the test structure had been installed by simulating. The numerical simulate design verified the working theory of these devices. The simulate model of the test had been established. By using numerical style instead of the real experiment, it would be simplified the design progress, shortening the develop circle and lower the costs by simulating model and the dynamic analysis of characteristic. Because of the structure limitation of cab-over-engine truck, the absorbing area was limited when the crash occurred. That would cause big deformation in cab structure and injured the occupant. It is important to do impact experiment and ensure the safety intension of cab. This paper described real impact experiment according two kinds of cabs. The deformation of two bumper were large to over 40mm and some parts took off the joint. The result of the impact experiment could guide the design of new bumper.The study method and the results of this paper have important evaluation in making superior of the positive bob impact test, promoting drawing up the commercial cab impact safety regulations, improving body structure , building the third generation simulate model and simulating the impact experiment of commercial vehicle.更多还原