The case study of Endurica ----Rassini

01

     Backgroud（背景）

Rassini is a global company that designs and manufactures components for suspension, brake and anti-vibration systems for the automotive industry, including both electric and internal combustion urban, family, off-road, sport, luxury and commercial vehicles. More than a manufacturer, Rassini is a design and solutions company, recognized worldwide as a pioneer in the development of new，technologies as well as constant innovation in product and process engineering.

Rassini 是一家全球性公司，为汽车行业设计和制造悬挂、制动和防震系统部件，包括电动和内燃机城市、家用、越野、运动、豪华和商用车辆。Rassini不仅仅是一家制造商，更是一家设计和解决方案公司，是全球公认的新技术开发以及产品和工艺工程方面不断创新的先驱。

The company’s 6,500+ employees work from eight production plants, five technology centers and offices in Mexico, the United States, Brazil, Germany and Japan. Rassini provides components to automakers in 10 countries, supplying over eight million vehicles every year. Furthermore, 51 vehicle models around the world use at least one Rassini product amid major original equipment manufacturers including General Motors, Ford, Toyota, Volkswagen, Tesla, Daimler, Audi, Mercedes Benz, Nissan, Volvo and Mitsubishi.

公司拥有 6500 多名员工，在墨西哥、美国、巴西、德国和日本设有八个生产工厂，五个技术中心和办事处。Rassin为 10 个国家的汽车制造商提供零部件，每年供应 800 多万辆汽车。此外，在通用汽车、福特、丰田、大众、特斯拉、戴姆勒、奥迪、奔驰、日产、沃尔沃和三菱等主要原始设备制造商中，全球有51款车型至少使用了一款Rassini产品。

02

     Issues (问题)

The jounce bumper is a key element of a vehicle’s shock absorber system. It prevents the metal shock absorber spring from reaching full compression during big impacts, and it improves the noise, vibration and harshness (NVH) characteristics. The jounce bumper design must qualify by enduring a sufficient number of load cycles without cracking. Rassini quickly gets the bumper material and design right before building a prototype by using Endurica to simulate the fatigue tests that will be used for qualification.

减震保险杠是汽车减震器系统的关键元件。它能防止金属减震器弹簧在受到较大冲击时达到完全压缩，并能改善噪音、振动和颠簸（NVH）特性。减震保险杠的设计必须能够承受足够次数的载荷循环而不会开裂。在制造产品原型之前，Rassini采用Endurica方案来模拟产品疲劳测试的过程，迅速搞定了保险杠材料和设计方面的耐久性问题。

03

    Solution Approach

Durability is a key requirement for Rassini's customers, and with Endurica's fatigue testing technology, Rassini is in a better position to provide technical information to its customers.Cross section view of the jounce bumper in the unloaded state. Displacement is applied sinusoidally along the vertical direction so that the jounce bumper is compressed between rigid end plates. Material properties for the simulation were tested using Endurica protocols implemented in Rassini’s lab.

耐用性是Rassini客户的关键要求，借助Endurica的橡胶材料疲劳测试技术，Rassini能够为客户提供更有效的产品技术信息。

下图1是卸载状态下的减震保险杠横截面图，位移沿垂直方向正弦施加，使得减震缓冲器在刚性端板之间被压缩。在Rassini实验室中，应用了Endurica材料测试方案，测试了被模拟材料的性能（用于结构仿真分析）。

Endurica CL correctly predicts fatigue cracking on the inside diameter of the jounce bumper for this load case.

Endurica CL 在这种载荷情况下正确地预测了减震保险杠内径的疲劳开裂，如图2。

Top down view of jounce bumper (left). Cracks in the fatigue test occur on the inside diameter (right), in accord with the location and orientation predictions of the Endurica CL simulation.

减震保险杠俯视图（图3左）疲劳试验中的裂纹出现在内径上（图3右），与Endurica CL模拟预测的位置和方向一致。