钢结构次梁设计模式与经济性比较研究

COMPARATIVE STUDY OF DESIGN PATTERNS AND ECONOMICS OF SECONDARY BEAMS IN STEEL STRUCTURES

钢梁设计模式有:弹性设计、考虑屈曲后强度设计和组合梁设计。由这3种设计模式出发,着眼于钢结构次梁设计,在相同的荷载和几何条件假设下,比较分析了满足承载能力和正常使用极限状态要求的次梁用钢量,得出组合梁设计为最优设计模式。在钢结构设计中,次梁设计宜优先采取组合梁设计或考虑屈曲后强度设计,腹板局部稳定的控制可采用临界剪切应力法,腹板高厚比不必局限于规范规定的限值80235/fy1/2,在满足结构安全的前提下,应使经济参数最优化。

There are three design patterns of steel beams which are elastic design, posvbuckling strength utilization design and composite beam design. These three design patterns in secondary beam design were investigated, and the steel quantity which meets the capacity and serviceability requirements under the same loading and geometry conditions was compared. Then it was concluded that the composite beam design pattern was the optimum design pattern. Finally, it was proposed that when the safety of structures was satisfied, composite beam design or post-buckling strength utilization design should be used in secondary beam design in preference. Besides, critical shear stress method should be adopted to control local stability of steel web rather than confining the width-thickness ration of web to the limiting valuein standard was proposed. Under the premise of ensuring structure safety, the economic parameters of secondary beam design should be optimized.