复杂机电产品中的螺纹连接工艺与失效机理研究

The tightening of threaded fasteners is the most widely used assembly connection in current complex electromechanical products, and the connection failure of threaded fasteners directly affects the assembly performance and reliability of the complex electromechanical products. As the increasingly harsh and extreme service conditions of the products, such as, high-speed railway, new aerospace vehicles, new tank and armored vehicles, and requirement of reliability, the harmfulness of the connection failure of the threaded fasteners is becoming more serious. The proposer intends to start the research on the tightening technology and failure mechanism of the threaded fasteners from practical engineering problems which include the control of scatter of threaded fasteners preloads and its connection failure in electromechanical products under the complicate service conditions. The research intends to develop the inner connection between the process parameters of threaded fasteners and the tightening performance from the point of macroscopic and microscopic view and then break through the key generic technology of tightening mechanism of threaded fasteners, process control and the forecast and experiment of the connection performance. The experiment platform for the test of the connection performance of threaded fasteners can also be established. All of these can be applied or validated in the improvement of the tightening and anti-loosing technology of threaded fasteners and its sealing performance in the driven and dynamical systems of the armored vehicles and this research can provide systematic theory, methods and technology for the reliability of threaded fasteners in electromechanical products under complicate service conditions.

螺纹连接是目前复杂机电产品装配中应用最广泛的装配连接方式，其连接失效直接影响复杂机电产品装配性能及可靠性，随着高铁、新型航空航天飞行器、新型坦克和装甲车辆等产品的服役条件恶劣化、极限化以及可靠性要求不断提高，螺纹连接失效的危害性变得更为突出。申请人拟从复杂服役条件下机电产品螺纹连接预紧力离散度控制与连接失效的实际工程问题出发，开展螺纹连接失效机理与高可靠性连接工艺方法研究，探索宏、微观尺度关联下的螺纹连接工艺参数与紧固性能物理量之间的内在科学联系，突破螺纹连接机理、工艺控制和连接性能预测及实验的关键共性技术，建立螺纹副连接性能测试等实验平台，并在装甲车辆的传动和动力总成中的螺纹预紧工艺和防松、密封性能改进中得到应用或验证，为我国复杂服役条件下机电产品螺栓连接可靠性保障提供系统的理论、方法和技术。

螺纹连接是目前复杂机电产品装配中应用最广泛的装配连接方式，其连接失效直接影响复杂机电产品装配性能及可靠性。.项目组从复杂服役条件下机电产品螺纹连接预紧力离散度控制与连接失效的实际工程问题出发，系统地开展螺纹连接失效机理与高可靠性连接工艺方法研究，取得系列创新成果：1）针对单螺栓和成组螺栓的拧紧控制，通过有限元仿真和拧紧实验研究了各种因素对单螺栓扭拉关系的影响规律，以及成组螺栓的弹性相互作用规律，在此基础上提出了单螺栓和成组法兰螺栓的拧紧优化方法；2）针对横向振动条件下的螺纹预紧力衰退和局部滑移累积过程，提出了包含三个阶段的预紧力衰退过程，采用改进的Iwan模型揭示了局部滑移演化机制；3）针对螺纹连接的密封失效问题，研究了弹塑性粗糙表面的实际接触面积的演变规律，基于此，提出并实验验证了一种密封性能定量评估方法，实现了静密封结构实际泄漏通道的提取和泄漏流量的准确定量计算，根据该方法反馈的实际泄漏流量，优化粗糙密封界面的表面加工工艺和密封结构的装配工艺。.项目研究成果在装甲车辆的传动和动力总成，以及卫星制造和航天器总装中的螺纹预紧工艺和防松、密封性能改进中得到了应用或验证。研究成果发表标注基金资助的学术论文19篇（其中SCI收录12篇，另有EI收录7篇），申请国家发明专利11项（已授权5项），已授权实用新型专利2项，培养博士生4人，硕士生2人，支撑获得了国防科技进步一等奖1项。