装配结合面跨尺度嵌套结构设计及连接性能优化

Aircraft engine, large spacecraft, heavy-duty gas turbine and other complex electromechanical systems generally include a large number of assembly interfaces. The connection performance of assembly interface is of great importance for reliability and safety of the complex electromechanical systems. However, the multi-scale contact characteristics of the jointed interfaces are still not fully understood. Furthermore, the assembly process is usually designed without considering the coupling influence of structure, interface, and process. These problems, therefore, obviously prevent the improvement of connection performance in the assembly interface. To this end, the main purposes of this project are as follows. First, a multi-scale model is established to calculate the contact characteristics (stiffness, damping, etc.) of jointed interfaces based on key parameters transfer (contact pressure, contact deformation, etc.). It can be used to accurately understand the response mechanism between the micro-geometric features and the macroscopic contact characteristics. Then, considering an efficient optimization method and the allocation criteria of design space at each scale, a multi-scale nested design for the geometry and surface topography of the joint surface is proposed to satisfy the different assembly performance. After that, the interactive influence of the preloads in the different position is revealed during connecting the members. Based on this, an optimization method for connection performance is presented by considering the coupling influence of structure, interface, and process. The research above will enlarge the basic theories of interface design and process guarantee, and fix the tough problem that the contact characteristics of the high-performance jointed interfaces cannot be controlled quantitatively. Finally, the accurate digital assembly of complex electromechanical systems can be achieved.

航空发动机、大型航天器、重型燃气轮机等复杂机电系统中存在大量结合面，装配结合面连接质量对于保障复杂机电系统可靠性与安全性具有重要意义。然而，目前装配结合面多尺度接触特性仍未被完全理解，连接工艺的制定也缺乏对结构、界面与工艺耦合影响的考虑，从而极大限制了复杂机电系统装配结合面连接性能的整体提升。为此，本项目拟构建基于关键参数传递（接触压力、接触变形等）的装配结合面连接特性（刚度、阻尼等）多尺度模型，准确把握微观几何形貌特征对宏观连接性能的响应机理；结合高效的优化设计方法与各尺度设计空间分配准则，探索满足不同装配性能需求的结合面几何形状与表面形貌跨尺度嵌套设计方法；阐明装配连接过程中不同空间位置载荷的交互影响规律，提出考虑结构-界面-工艺耦合的装配连接性能优化设计方法，丰富结合面设计与工艺保障的基础理论，突破高性能装配结合面连接性能难以量化控制的难题，实现复杂机电系统的精准数字化装配。

针对复杂精密机电系统对装配结合面高服役性能、高可靠性、高性能保持性等高性能需求，本项目研究了微凸体弹塑性非线性接触变形机制，构建了基于关键参数传递的装配结合面接触特性模型，与传统计算模型相比，该模型可以考虑微凸体的实际大小及空间分布，更符合装配结合面的实际接触状态；提出了装配结合面“曲面化”设计代替传统“线性化”设计的思路，通过几何形貌主动设计，实现了装配结合面接触特性的量化控制，提高了外载作用下装配连接载荷的保持性；建立了考虑真实接触压力分布和螺纹三维几何特征的装配连接扭矩-载荷动态关联模型，解决了传统方法易受压力分布假设影响难以实现连接载荷精确预测与量化控制的问题；提出了螺纹组连接载荷弹性交互作用力学建模方法，开发了面向载荷均布的最少批次连接工艺优化设计技术，突破了传统多批次连接工艺冗繁复杂、出错率高、且最终载荷难以量化控制的难题。项目研究工作丰富了结合面设计与工艺保障的基础理论，实现了复杂精密机电系统的精准数字化装配。