高性能不锈钢复合钢材轴心受压构件整体稳定性能与设计方法研究

Clad steels fabricated from stainless steels as the cladding metal and conventional mild steels as the base metal possess significant benefits in terms of both low cost and high performance. Despite a mature industrial base and practical engineering experience as well as potential application in structural engineering being formed and indicated, there is little research reported in the literature on this new subject. Overall buckling behaviour of such clad steel columns subjected to axial compression is investigated in this project through full-scale experimental studies, numerical modelling and parametric analyses as well as theoretical research. Essential principle of effects of imperfections including geometric imperfections, cross-sectional residual stresses and compound contact interface imperfections (i.e. distribution of division regions) is clarified scientifically and quantitatively. By modelling the constitutive mechanics of the clad steel material, the residual stresses and the random distribution of the compound contact interface imperfections, fundamental mechanisms during the whole overall buckling process of the clad steel columns subjected to axial compression are elucidated systematically. On this basis, complete, accurate and robust design theories and calculation methods are developed for predicting the overall buckling behaviour of such columns. Research outcomes of this projects are prospective and advanced, which may fill the gap for the research on mechanical performance of the clad steel structures internationally and create a new design theory system and lead modern academic research focus in the world. It is also helpful for promoting the engineering application of the stainless-clad steels in construction.

不锈钢复合钢材兼具低成本与高性能的优点，在我国已具备了一定的产业技术基础和工程应用实践经验，且在结构工程领域的应用前景十分广阔，但国内外相关基础研究基本处于起步阶段。本项目通过足尺试验研究、数值建模计算及参数分析并结合理论分析，深入系统地研究该新型不锈钢复合钢材轴压构件的整体稳定受力性能，科学定量地阐释不锈钢复合钢材力学特性和构件初始缺陷（包括几何初始缺陷、截面残余应力、材料复合界面缺陷（即未结合区分布）的影响机理；通过建立不锈钢复合钢材的材料力学本构模型、截面残余应力分布模型及钢材复合界面缺陷随机分布模型，系统阐释不锈钢复合钢材轴压构件的整体失稳全过程力学机理，并制定完整、准确、可靠的设计理论和计算方法。本项目的研究内容和成果具有理论前瞻性，将弥补国内外针对复合钢材结构受力性能研究的不足，建立相应的设计理论体系，并能够引领国际学术研究热点；同时有利于推动国内外不锈钢复合钢材的工程应用。

不锈钢复合钢材是一种兼具优秀的力学性能和使用性能（耐蚀性）及综合成本优势的新型高性能钢材，并且在我国已具备了一定的产业技术基础和工程应用实践经验，在结构工程领域的应用前景十分广阔，但国内外相关基础研究还处于起步阶段。本项目通过足尺试验研究、数值建模计算及参数分析并结合理论分析，深入系统地研究了该新型不锈钢复合钢材轴压构件的整体稳定受力性能，科学定量地阐释了不锈钢复合钢材力学特性和构件初始缺陷（包括几何初始缺陷、截面残余应力、材料复合界面缺陷（即未结合区分布）的影响机理。通过对不锈钢复合钢材的材料力学性能进行试验研究，包括常温下、高温下、高温后单调拉伸性能和常温循环荷载下的力学性能，提出了不锈钢复合钢材的材料本构模型。使用分割法对不同尺寸的焊接截面进行残余应力测量试验，并提出相应的分布规律和模型，用于受压构件的整体稳定性能分析。通过弹性屈曲分析、弹塑性整体稳定轴压试验，系统阐释了不锈钢复合钢材轴压构件的整体失稳全过程力学机理，并提出了相应的设计理论和计算方法。本项目的研究内容和成果具有理论前瞻性，将弥补国内外针对复合钢材结构受力性能研究的不足，建立相应的设计理论体系，并能够引领国际学术研究热点，推动双金属复合材料的研究和工程应用。