基于突变理论的极端制动工况下摩擦材料摩擦失效行为研究

For the friction under high sliding speed and heavy load, the braking friction material is focused with high temeprature and concentrated heat-stress coupling under some extreme braking conditions. It then loses easily its normal tribological performance to induce serious accidents. Based on some experiments of the friction mateial under some extreme braking conditions, this project is going to reveal the friction failure mechanisms by the methods combining of experimental investigations, computer simulations and theoretical analysis. Firstly, the braking frction heat and its dynamic distributing mechanisms will be investigated by the simulating braking experiments under some extreme conditions, also by the testing of its dynamic thermal, physical and mechanical performance. Secondly, the friction failure mechanisms of the friction materials will be revealed by combining of the braking experimental results and the micro analysis of worn surface of the friction samples. Finally, a catastrophe model describing the friction failures of the friction materials will be established based on the catastrophe theories. A method forecasting the friction failures will be pointed out and verified by experiments. It is believed that the results may be theoretically valuable for avoiding any serious accidents induced by the friction failures and technologically helpful for developing of new high quality friction materials.

在机械系统极端制动工况下，制动摩擦副由于高速重载相对滑动，致使摩擦材料承受极高温度和热-应力耦合作用，其材料性能极易发生突变导致摩擦失效，从而引发恶性事故。本项目采用试验探索、计算机仿真与理论分析相结合的研究方法，通过对极端工况下典型制动摩擦材料的试验研究，基于突变理论揭示摩擦材料的摩擦失效机理，并预测其突变行为。首先，针对机械系统极端制动工况开展模拟制动试验，并结合摩擦材料的动态热物性能和热机械性能试验，研究制动摩擦热及其动态热流分配机制；其次，基于模拟制动试验结果，并结合磨损试样表面的微观分析试验，研究摩擦材料的摩擦失效机理；最后，基于突变理论，建立极端工况下摩擦材料摩擦失效的突变模型，提出摩擦失效的预测方法，并通过试验进行验证。本项目的研究结果可为避免因摩擦材料摩擦失效而引发的机械系统恶性事故提供重要的理论基础，并可为高性能摩擦材料的研制提供有益的技术指导。

本项目针对机械系统高速重载等极端制动工况，基于突变理论揭示了极端制动工况下摩擦材料的摩擦失效机理并预测其突变行为，研究结果可为避免因摩擦材料摩擦失效而引发的恶性事故提供重要理论基础、为高性能摩擦材料的研制提供有益技术指导。首先，通过开展摩擦材料动态热物性能和热机械性能试验，研究了制动过程动态摩擦热行为，揭示了摩擦热在制动摩擦副之间的动态热流分配机制，建立了摩擦材料的三维温度场模型及热-应力耦合模型。其次，改造盘式制动器模拟制动试验台，构建了极端制动工况下摩擦材料摩擦失效行为试验手段；开展无石棉有机等典型摩擦材料在极端制动工况下的模拟制动试验和微观分析试验，掌握了摩擦材料在极端制动工况下的摩擦失效规律；从摩擦学、材料学等基本原理出发，揭示了极端制动工况下摩擦材料的摩擦失效机理。最后，基于突变理论建立了极端制动工况下摩擦材料摩擦失效行为表征方法；分析极端制动工况下摩擦材料摩擦失效的临界状态及其关键特征参量，建立了摩擦失效突变模型；构建了极端制动工况下摩擦材料摩擦失效突变行为预测方法，并通过试验进行了验证。在项目执行期内，已发表学术论文4篇（SCI检索3篇），另在SCI源刊录用论文1篇；出版专著1部；公开发明专利4项；培养博士后出站1人、毕业硕士生2人。