Experimentelle Untersuchungen und Modellierung von Spannungszuständen während des Gleitverschleißes von Verbundwerkstoffen gegen Stahl

在以前的DFG项目中，采用了许多不同的实验和数值方法来研究复合材料与钢之间的滑动磨损。基于接触力学方法的数值技术，利用各向异性数值接触算法研究了--实际复合材料与钢表面之间的滑动接触，--在粗糙表面和真实表面水平上的接触温度发展，--在PEEK基体材料上的转移膜的形成。实验研究评估了静载荷和滑动载荷条件下的接触条件，并测量了在与钢对偶的滑动接触下，作为纤维取向函数的基体和复合材料的摩擦磨损性能。无论是数值研究还是实验研究，都主要描述了复合材料滑动过程的宏观环境，而不是将结果“传递”到复合材料的微观结构中。在本项目方案中，所开发的方法与热和非线性微观模型相结合(使用所述耦合技术)将描述纤维增强复合材料与钢体之间的基本失效模式和不同的磨损机制，其中考虑了滑动粗糙接触，进而转移膜和磨屑的形成。要研究这些摩擦学过程，需要从宏观层面切换到微观层面，使用微观模型来评估热产生、应力和应变，并考虑滑动磨损过程中涉及的聚合物材料的不同成分(基质、纤维、界面)的失效准则。实验研究将集中于观察基本的失效模式(在微观层面)，提供更现实的失效标准和所需的材料数据。最终目的是研究不同的试验参数对磨损机理的影响，从而预测如何提高复合材料的摩擦学性能。

In the previous DFG project sliding wear of composites against steel has been studied following many different experimental an numerical techniques. The numerical techniques based on an approach of contact mechanics to study- asperity contact phenomena using anisotropic numerical contact algorithms,- sliding contact between real composite and steel surfaces,- contact temperature development on asperity as well as on real surface level,- transfer film formation on PEEK matrix material.The experimental studies evaluated the contact conditions under static loading and sliding loading conditions, and they dealt with measurements of the friction and wear properties of the matrix and the composites as a function of fibre orientation under sliding contact against a steel counterpart. Both, the numerical and the experimental studies described mostly the macro-environment of the sliding process of the composite against stelle withaou 'transferring' the results obtaines to the composite micro-structure. In the present project proposal the developed approaches combined with thermal and nonlinear micro-models (using the coupling technique presented) will characterise the basic failure modes and different wear mechanismus between fibre-reinforced composites and steel bodies, considering sliding asperity contact, furthermore transfer film and wear debris formation. To study these tribological processes requires to 'switch' from a macroscopic level to a microscopic level, using micro-models to evaluate heat generation, stresses and strains, and to consider failure criteria for the different components (matrix, fibers, interface) of the polymer material involved in the sliding wear process. The experimental studies will concentrate on observing basic failure modes (on microlevel) providing more realistic failure criteria and material data required. The final goal ist to study the effect of different testing parameters on the wear mechanismus and in this to predict how the tribological performance of composites can be improved.