高性能铝合金结构体系应用的关键问题研究

Aluminum alloy has wide application prospect because of its excellent performances of lightweight, high effects and corrosion resistance. However, its weakness, such as low ductility and HAZ softening adjacent to welds, limits its further applications. The applicant was the editor-in-chief of "Code for design of aluminum structures" (GB50429-2007) and research achievements of aluminum structures were summarized in the code. The application of the code promotes the development of aluminum structure engineering, and new research topics in turn are put forward with the wide application of aluminum structures. The project is devoted to the study of key issues on materials, joints and systems of aluminum structures. First, to meet engineering requirements, mechanical properties will be studied and improved through measures such as adjusting chemical composition of aluminum alloys; Second, to realize force transmission mechanism continuously, new types of aluminum connections will be developed and the construction、performance and failure mechanisms of aluminum connections will be further studied. Third, to give full play to performances and characteristics of ease to manufacture of aluminum alloys, aluminum alloy components and systems will be innovated. Fourth, further studies on design theories of aluminum alloy structures will be needed to developed, including determining structural damping ratio parameters, stability design for large-scale aluminum component, overall stability for aluminum structural systems and so on. In short, through theoretical and experimental methods, combining with the on-site monitoring, the chemical composition of new aluminum alloys will be suggested, mechanical properties and design indexes of the aluminum alloys will be proposed; new connections, new components and new system of aluminum structures will be developed; the necessary design parameters, theories and methods of aluminum structures will be summarized for applications. The systematic research will provide theoretical basis for the revision work of the national standard "Technical specification of aluminum alloy structures" which has already been approved. Technical supports will be given for further promotion of aluminum structure engineering.

铝合金轻质、高效、耐腐蚀，具有广阔的工程应用前景,但其延性和焊接热影响对应用造成一定困难。申请人主编的《铝合金结构设计规范GB50429-2007》总结了铝合金结构研究成果、促进了工程应用，同时工程应用对铝合金结构研究提出了新课题。本项目致力于研究解决铝合金结构材料、节点、体系的关键问题。一、满足工程要求的改性铝合金材料及其力学性能问题；二、具有连续传力机制的铝合金节点构造、性能和破坏机理问题；三、充分发挥铝合金材料和制作特性的新型单元和体系的创新问题；四、新型铝合金结构的设计理论问题，包括结构阻尼比参数、大尺度构件稳定设计、结构体系稳定等。通过理论、试验和现场监测研究，提出改性铝合金化学成分、力学性能及设计指标；创建铝合金新节点、新单元和新体系；提出应用必须的铝合金结构设计参数、理论和方法，为已批准的国家标准《铝合金结构技术规范》修编工作提供理论依据，为铝合金结构进一步推广提供技术支撑。

项目针对铝合金材料力学特性、基本构件稳定设计方法、新型节点受力机理和性能进行全面、深入、系统的研究。在材料性能方面，获取了国产7075-T6高强铝合金材料力学性能指标和设计参数，研究了国产6061-T6挤压铝合金型材及轧制铝合金板材在复杂应力状态下的塑性演化和延性断裂准则。在基本构件方面，进行了异形大尺寸铝合金截面轴压构件数值分析、大尺寸工字形梁受弯承载力试验研究、国产高强铝合金轴压构件整体稳定性能试验研究、压弯构件局部稳定性能的试验研究、数值分析，局部稳定设计方法的试验研究，对大截面铝合金基本构件的稳定设计方法和构造措施提出了建议。在新型节点方面，基于塑性演化和延性断裂准则，对高强铝合金轴心受力构件板式节点的验算公式进行了修正和比较，研究了新型自由曲面铝合金单层网壳结构体系的板式节点面内和面外的力学性能，明确了新型节点面内和面外的弯矩-转角关系。在结构体系方面，进行了铝合金单层球面网壳和柱面网壳的阻尼特性试验研究，对铝合金一体化单层网壳屋面的阻尼参数进行了识别和建议。项目取得了预期研究成果，部分成果在修编的《铝合金结构技术标准》中引用，达到了预定的研究目标。