Collaborative Research: An Efficient BEM Formulation for Thermal-Mechanical Problems in Tribology

0099854 Wang和0099646绿色摩擦加热经常导致许多摩擦学元件失效。研究热效应和机械效应的结合是理解热致失效和机械零件及其摩擦表面整体性能的关键。然而，对于保形接触，例如轴承和密封件，分析变得非常困难，因为它们通常涉及元件部件的宏观尺度结构分析，以及滑动/滚动界面处的微观尺度接触/润滑计算。目前，通常的做法是使用商业有限元软件包来解决这些问题。边界元法（BEM）被期望提供一个更有效的解决方案，因为从摩擦学的角度来看，本质上所有重要的都发生在相互作用表面的边界处。因此，BEM公式预计将减少模拟工作量和计算时间的数量级（因为只有边界需要网格化和解决）。因此，可以更快地实现润滑、弹性和热效应的三向耦合问题的解决方案，从而在设计和分析中有效。由于网格化仅在边界上是必需的，因此也显著减少了计算机存储。因此，边界元法（BEM）是最合理和有效的手段，用于热-机械问题的摩擦学。拟议的合作研究的目的是发展一个通用的边界元法（BEM）的制定热-弹性边界条件下的摩擦学元件具有任何一般的几何形状的热-机械问题。 其他的计算技术，如FFT和宏微观的方法将使边界元制定一个完整的和最有效的数值方法，复杂的摩擦元件的热机械问题。在摩擦学中的热和机械现象的组合建模将提供性能分析和故障模拟之间的必要联系。本文首次尝试用边界元法求解有限结构的热机械接触问题。它有望成为一个重要的和最有效的计算工具，接触分析问题的半空间绿色的功能/积分或有限元方法变得不准确或计算不切实际。 这项工作将与格鲁吉亚理工学院和西北大学现有的表面工程和摩擦学中心（CSET）正在进行的研究一起进行，该中心由NSF和参与行业共同资助。拟议的研究将连接王教授的小组在NU的接触模拟能力，并建立在绿色教授在GT的工作，对摩擦元件的分析，故障模拟和预防。绿色和王的专业知识的融合将构建一个全新的，有效的，准确的分析工具，分析实际摩擦元件的热机械失效。新方法将大大加强CSET的研究，使其成员以及美国其他行业在改进设计和推出新产品方面受益。

0099854Wangand 0099646GreenFrictional heating often causes failure of many tribological elements. Investigating the combined thermal and mechanical effects holds the key to understanding heat-induced failure and the overall performance of machine parts and their tribological surfaces. However, for conformal contacts, such as in bearings and seals, analyses become very difficult because they typically involve macro-scale structural analyses of the element parts, and micro-scale contact/lubrication calculations at the sliding/rolling interfaces. The common practice today is to use commercial finite element packages to solve such problems. The boundary element method (BEM) is expected to provide a far more efficient solution, because by nature all that is important, from a tribological point of view, occurs at the boundaries of the interacting surfaces. Therefore, the BEM formulation is expected to reduce the simulation effort and computation time by orders of magnitude (because only the boundaries need to be meshed and solved for). Therefore, the solutions for the problem of the three-way coupling of lubrication, elasticity, and thermal effects can be achieved much faster to be effective in design and analysis. Because meshing is necessary on the boundaries only, also computer storage is reduced significantly. It is, therefore, that the boundary element method (BEM) is the most reasonable and efficient means to use for thermal-mechanical problems in tribology.The proposed collaborative research aims at developing the formulation of a general boundary element method (BEM) for thermomechanical problems of tribological elements having any general geometry subject to thermal-elastic boundary conditions. Other computational techniques, such as the FFT and the macro-micro approach would make the BEM formulation a complete and the most efficient numerical method for thermomechanical problems of complex tribological elements. The modeling of the combined thermal and mechanical phenomena in tribology will provide the needed link between performance analyses and failure simulation. This work is the first attempt to solve the thermomechanical contact problem of finite structures with the boundary element method. It is expected to become an important and the most computationally effective tool for contact analysis problems where the half-space Green's function/integral or the FEM approaches become either inaccurate or computationally impractical. This work will be performed in conjunction with the ongoing research at the existing Center for Surface Engineering and Tribology (CSET) at Georgia Tech and Northwestern University, which is co-funded by NSF and participating industries. The proposed research will link the contact simulation ability of Professor Wang's group at NU, and build upon Professor Green's work at GT on the analysis of triboelements, failure simulation, and prevention. The fusion of expertise by Green and Wang will construct an entirely new, efficient, and accurate analytical tool for analyzing thermomechanical failure of practical triboelements. The new approach will greatly enhance the CSET research, benefit its membership as well as other US industries in their efforts to improve designs and introduce new products.