流致振动诱发间隙配合面冲击微动磨损的基础研究

The flow-induced vibration often occurs in a nuclear power plant unit，electrical power ,etrifaction industry,etc.Impact fretting wear usually appears at the clearance fit interface under the flow-induced vibration environment,and it often affects the service life of the material. This project on the basis of the numerical simulation of contact mechanics, though the transformation bench and control of experimental conditions, and excited vibration through an external source. The research will simulate the tribology interface condition of the flow-induced vibration induced environment. It plans to investigate the influence with a variety of experimental conditions(interfacial friction amplitude, vibration amplitude, the normal load, the frequency ,contact time and number of cycles, etc.), the environment (fluid temperature and chemical composition) for clearance fit surface imfact fretting wear damage to reveal its tribology and damage mechanism. The research will combine the analysis of mechanical action and tribochemical role in the mechanism of competition.It will explore and reveal the failure mechanisms. Advanced surface technology (texture, high-energy beam processing, etc.) will be used to achieve effectively control of convection induced vibration wear failure. It try to find the method to improve the interface tribology condition from the tribological design point..This project is based on the basic science of the national major needs-nuclear power plant operational safety issues. It has important scientific significance and engineering applications value.

流致振动在核电、电力、石化等领域中经常发生,使得构件如蒸汽发生器中传热管/抗振条配合界面不可避免的产生冲击微动磨损，进而产生破损，造成重大事故。本项目在接触力学数值模拟的基础上，改造实验台并控制试验条件，通过外激振动源，模拟并实现流致振动诱发的冲击微动摩擦学条件，实现间隙配合面的冲击微动磨损。模拟并考察位移幅值、冲击载荷、频率、接触时间、循环次数及环境（流体温度及碱性水环境）等参数对冲击微动磨损材料损伤过程的影响, 探讨和揭示间隙配合面冲击微动磨损的失效机理和主要影响因素，并重点分析机械作用、摩擦化学作用在其中的竞争机制，试图从摩擦学设计角度提出改善界面摩擦学损伤的方法。本课题立足于国家重大需求-核电站运行安全的基础科学问题,开展模拟流致振动条件下,间隙合面的冲击微动摩擦学行为的试验、理论研究，有着重要的科学意义和工程应用价值。

本项目对于核电装备中流致振动引发的冲击微动磨损现象，本研究在设计研发了新型冲击磨损试验机并建立了基于冲击动力学响应的材料冲击磨损性能表征方法。针对流致振动背景，对典型核电用材料690合金管、Zr-4合金管和304不锈钢管在各种复杂实验工况条件（管径厚比、支撑角度、支撑跨距、支撑结构、预应力等）下的冲击动力学响应和磨损行为开展了系统而深入的研究。揭示了其摩擦动力学特性和材料损伤过程的规律，探讨了接触界面的失效机理和主要影响因素。结果表明：（1）结构刚度对管材的冲击力、能量吸收和冲击磨损有显著的影响；（2）悬臂支撑时的冲击变形远大于简支支撑，且峰值力、吸收能等动力学响应指标与磨损量之间有较高的相关性；（3）预应力的施加，会导致能量吸收的减小，并趋于平稳。此外，本项目研究了不同的典型金属材料、涂层材料和生物材料的冲击磨损特性，材料性能差别大，界面的力学结构刚度不一样。从摩擦学的角度，揭示了材料机械性能、表面工程技术、自然生物特性等对冲击磨损的作用，为冲击微动摩擦学行为的控制，提供了重要的依据和指导意义，丰富了摩擦学研究和相关理论，为机械界面摩擦学的测试方法提供了新的手段。