1、毕 业 设 计（论 文）外 文 参 考 资 料 及 译 文译文题目： Experimental Evaluation of the Attenuation Effect of a Passive Damper on a Road Vehicle Bumper 被动阻尼器对道路车辆保险杠 衰减效果的实验评价 学生姓名： 学 号： 专 业： 所在学院： 指导教师： 职 称： 20xx年 2月 27日说明：要求学生结合毕业设计（论文）课题参阅一篇以上的外文资料，并翻译至少一万印刷符（或译出3千汉字）以上的译文。译文原则上要求打印（如手写，一律用400字方格稿纸书写），连同学校提供的统一封面及英文原文
2、装订，于毕业设计（论文）工作开始后2周内完成，作为成绩考核的一部分。外文原文Experimental Evaluation of the Attenuation Effect of a Passive Damper on a Road Vehicle BumperAbstract：To mitigate the degree of damage to passengers caused by automobile collisions, a friction damper was built and used in experimental tests to test its effectiv
3、eness in impact energy attenuation. The study revealed that energy absorption capacity of a bumper can be improved with the addition of a friction damper. The results revealed that the addition of the friction damper to an automobile bumper to give a bumper-damper system could attenuate about 32.5 %
4、 more energy than with the bumper alone. It can be concluded that the effectiveness of automobile bumpers to withstand impact of vehicles by absorbing the kinetic energy from the impact can be improved with the use of a passive friction damper. That is, a passive friction damper system could be used
5、 to attenuate more road vehicle impact energy in collisions.Keywords：Vehicle Bumper, Equivalent Energy Speed (EES), Impact Attenuation, Passive Damper1. IntroductionOver the past 20 to 30 years, Bumper design concepts have changed drastically. EEA 6 describes four basic bumper design principles (Whe
6、re necessary, specific features can also be combined). They are: First, the traditional design with a visible metallic transverse beam that decorates the front or rear end of the vehicle and acts as the primary energy absorber during collision； which is seldom used today. Secondly, the plastic fasci
7、a and reinforcing beam system that is fixed directly to the front/rear longitudinal beams. This design increases the overall vehicle crashworthiness but leads to a small sacrifice in bumper performance. Thirdly, the system consisting of three components: a plastic fascia, a reinforcing beam and mech
8、anical energy absorbers. The energy absorbers come in two types. They may be either of a reversible type (“shock absorbers”) or deformation elements (“crash boxes”) which are usually replaced after a crash. Lastly, a system, which is more pedestrian friendly in leg impact, which includes a plastic f
9、ascia, a reinforcing beam and a propylene foam or a honeycomb energy absorber placed between the plastic fascias and reinforcing beam.An automobile bumper is the front-most or rear-most part, specially designed to allow the car to sustain low speed impact without damage to the vehicles safety system
10、s. That is, they are not capable of reducing injury to vehicle occupants in high speed impacts 7 8. It is required to pass an impact test at 4 km/h (2.5 mph) with novisible damage to the body. Bumpers keep safety-related equipment such as headlights and taillights, hoods, fenders, exhaust and coolin
11、g systems, away from damage. Some bumper designs have the provision of cushioning and support of the lower limb； as well as the integration of impact sensors and exterior airbags 9. The main method proposed for cushioning the lower limb in an impact uses an energy absorber in front of a semi-rigid b
12、eam. Energy absorbers proposed include plastic foams (single or multi-density), molded plastic “egg-crates”,“spring-steel”, composite steel-foam, and crush-can energy absorbers 9. Exposed steel bumpers that involvefrontal airbags design are also alternative design concepts that appear to be adaptabl
13、e to meet the pedestrians safety requirements but these may be costly and require advanced sensors to function efficiently 9.Bumpers could be designed to absorb more energy than they usually do with some modification of the design and possibly with the use of additional energy absorption devices. Th
14、is work seeks to apply a passive control system which is an uncontrolled damper that requires no input power to operate. Passive control systems attenuate or absorb vibrations automatically without the need of an electrical control system. They are simple and generally low in cost, but are unable to
15、 adapt to changing needs after installation. The passive control system was selected for this work because of its stability, simplicity and low cost in its application. Passive systems include base isolation systems, viscoelastic dampers, bracing systems and friction dampers 12. Base isolation systems are used to isolate the dynamic force transfer from the structure to the base. Viscoelastic dampers attenuate the force due to external loads using their natural damping properties. Bracing syste
