Influence of stress conditions in roller bearings on the damage mechanism of White Etching cracks (WEC)

该项目的研究目标是调查产生白色蚀刻裂纹（WEC）的机械、热和化学应力条件。利用实验中参数的系统变化来识别各参数对裂纹网格生长的影响。了解这些重要参数后，就可以确定损坏过程中的作用模式，并采取补救措施，以避免这些轴承故障。除了再现白色蚀刻裂纹损伤外，还旨在确定一种状态监测程序，以便在早期阶段识别损伤并调查轴承尺寸的影响。位于凯撒巴登和汉诺威的三个研究中心（机械零件、齿轮和传动研究所（MEGT），凯撒巴登大学，材料测试工作组（AWP），凯撒巴登大学，汉诺威莱布尼茨大学机械部件、工程设计和摩擦学研究所（IMKT）提供他们的专业知识和实验室设备。组件测试在MEGT进行三轴动态载荷下使用现有的电力和液压驱动器。此外，多体仿真用于研究内部轴承动力学，特别是相关的接触力和应力。IMKT开发了一个基于组件相关测试样本的系统模型。该模型描述了轴承套圈的内部应力。此外，滚动体轨道接触的详细研究，使用一个专门的摩擦试验机。AWP侧重于测试样本的单轴和多轴应力。AWP的经验和设备也被用来调查其他机构的样本，以确定WEC。一个机构的结果直接转发给其他机构进行验证，例如关于WEC形成的负载场景。

The research objective of the project is the investigation of the mechanical, thermal and chemical stress conditions which create white etching cracks (WEC). Systematic variations of parameters in experiments are used to identify the individual influence of parameters for growing of crack meshes. With the knowledge of these important parameters it is possible to work out the mode of action in the damage process and derive remedial actions to avoid these bearings failures. Beside the reproduction of white etching crack damages it is also intended to identify a condition monitoring procedure to identify damages at an early stage and to investigate the influence of the bearing size.Three research sites in Kaiserslautern and Hannover (Institute of Machine Elements, Gears, and Transmissions (MEGT), University of Kaiserslautern, Working Group of Materials Testing (AWP), University of Kaiserslautern, Institute for Mechanical Components, Engineering Design and Tribology (IMKT), Leibniz University of Hannover) provide their expertise and their laboratory equipment. Component tests are performed at the MEGT under triaxial dynamic loads using existing electric and hydraulic drives. In addition multi-body simulation is used to investigate the internal bearing dynamics and especially the associated contact forces and stresses. The IMKT develops a system model based on component-related test specimen. This model describes the internal stresses of the bearing rings. Moreover the rolling element track contact is studied in detail using a specialized tribometer. The AWP is focused on single- and multi-axial stressing of test specimen. The experience and equipment of the AWP is also used to investigate samples of the other institutions to identify WEC. Results of an institute are directly forwarded to the other institutions for verification, for example regarding a load scenario with WEC formation.