大跨度钢结构分步施工模拟方法

Simulation Method of Step-by-Step Construction of Long-Span Steel Structures

针对施工过程中结构几何及边界条件随时间不断变化这一施工力学分析难点,基于先装和后装结构间可通过节点设计构造预夹角的工程实践,提出"生死"子结构先后独立求解、调整"死"结构边界节点转动约束条件的施工模拟方法.分别针对"死"结构为静定和超静定的体系,阐述了两种边界转角条件的调整方法,推导了"生死"子结构的有限元方程,并用该方法对典型算例进行分析、模拟.结果表明,该施工工艺便于后装结构加工且后装结构变形较小,施工完成后结构更接近设计原型.

One of the difficulties in mechanical analysis of construction process is the time variable of structure geo-metry and boundary conditions.In this investigation,first,based on the engineering practice that a pre-angle can be set between pre-erected and after-erected substructures via an inter-node design,a new construction simulation method is proposed.In this method,live and dead substructures are solved sequentially,and the rotational constraint on boundary nodes of dead substructures can be adjusted.Then,for the system with statically-determined or super-determined dead substructures,two methods to adjust the boundary rotational condition are presented,and the finite element formulas of live and dead substructures are respectively derived.Finally,the proposed method is used to analyze and simulate some typical cases.The results indicate that,by using the proposed method,the after-erected substructures deform more slightily and can be facilitated more easily.As a result,the final geometry is closer to the design shape.