腹板开孔不锈钢焊接工字形梁局部稳定机理及承载力分析方法

不锈钢具有力学性能好、耐腐蚀性能好、碳排量低、维护成本低等优点，被广泛应用在建筑承重构件中，符合国家“双碳”战略。不锈钢梁由于设施管线的穿越需要在腹板上开孔，导致构件承载力降低，局部稳定性问题也更加突出。但是，目前针对腹板开孔不锈钢焊接工字形梁的局部稳定研究较少，也缺乏可靠承载力分析方法。.本项目主要以试验研究、数值模拟和理论分析相结合的方法，试验研究中针对腹板开孔不锈钢焊接工字形梁的局部稳定性能开展弯剪和局部承压试验，揭示局部荷载作用下不锈钢构件的局部稳定机理。数值模拟研究中通过建立精细化有限元数值模型，进行参数化分析，确定关键因素对其承载力的影响规律。理论研究中通过改进空腹桁架理论和屈曲后强度理论，提出腹板开孔不锈钢焊接工字形梁的局部稳定承载力计算公式。本项目的研究对于改进和完善不锈钢的设计理论，促进腹板开孔不锈钢的实际工程应用具有重要的意义。

Stainless steel members are an increasingly popular choice as load-carrying members in building due to their advantages, such as good mechanical properties, good corrosion resistance, low carbon emission, and low maintenance cost, and it can achieve China’s carbon peak and neutrality targets. Such stainless steel sections often include openings at the web for installation of service, which will reduce their capacity and affect local buckling behaviour. However, limited research work and design guidelines were reported in the literature investigating the welded stainless steel I-section beams with web openings...This study is mainly based on the combination of experimental research, numerical simulation and theoretical analysis. The welded stainless steel I-section beams with web openings under shear and concentrated loading were tested, which revealed the mechanical mechanism of local instability of stainless steel flexural members. In the numerical simulation study, a finite element numerical model was developed, and the parametric analysis was conducted to determine the influence the key parameters on its bearing capacity. In the theoretical study, the calculation formula for determining the capacity of welded stainless steel I-section beams with web openings were proposed by improving the vierendeel truss theory and post-buckling strength. The significance of this study is to improve and perfect the design rules of stainless steel, which can significantly promote the practical application of such welded stainless steel I-section beams with web openings.