某重型车间双层肩梁加固的非线性分析

NONLINEAR ANALYSIS OF DOUBLE-LAYER SHOULDER BEAM REINFORCEMENT IN A HEAVY WORKSHOP

某重型车间双层肩梁在施工完毕后发现,因钢结构制作安装误差导致吊车梁支座中心线与支承加劲肋中心线存在较大偏差,从而导致结构主体不满足设计要求,需要对现有双层肩梁进行安全评估并提出合理的加固方案。首先选取格构柱肢的上层肩梁为研究对象,通过简化力学模型分析了肩梁的受力机理,然后采用ABAQUS软件对现有不加固的双层肩梁进行竖向偏心荷载作用下的有限元模拟,并对提出的双层肩梁单、双侧加固方案分别进行有限元仿真模拟,最终得到双层肩梁中每层肩梁的合理加固方案。分析表明:因放置于肩梁上盖板的较厚垫板对荷载传递路径有很好的调节作用,使垫板对吊车梁安装偏差具有普遍的适应性;由施工误差导致的竖向偏心荷载作用下,其最大应力值均超过了钢材的设计强度;在合理的净距下,单、双侧加固对每层肩梁都能起到较好的加固效果,同一净距下双侧加固效果要好于单侧加固;结合现场加固施工的可操作性,上层肩梁加固方案采用双侧加固,净距取150 mm;下层肩梁加固方案采用单侧加固,净距取120 mm。

This paper generated from the construction of double-layer shoulder beam of a heavy workshop. After the completion of this construction, there is a great deviation between the center line of crane girder support and the center line of bearing stiffener due to steel structure production installation, which is not desirable for design requirements. Therefore, it is imperative to make a safety evaluation for the double-layer shoulder beam and to put forward a reasonable reinforcement program. Taking the shoulder beam of lattice column limb as case study, the paper analyzed the force mechanism of shoulder beam by simplifying the mechanical model;an accurate finite element simulation analysis for the unreinforced shoulder beam under vertical eccentric load action;a finite element simulation was carried out for the unilateral and bilateral reinforcement scheme of shoulder beam in order to acquire a reasonable reinforcement scheme of each-layer shoulder beam. Finally, the paper drawn the following conclusions: the thick backing plate between the cover plate and the shoulder beam had a regulation effect on the load transfer route and could adapt to the deviation of crane girder installation;the maximum stress of vertical eccentric load caused by the construction deviation excecded steel strength in the design;at a reasonable clear distance, the unilateral and bilateral reinforcement had a good effect on the reinforcement of each-layer shoulder beam, meanwhile, at the same clear distance, bilateral reinforcement was better than unilateral reinforcement;considering the feasibility of site construction, the bilateral reinforcement method was adopted in the upper shoulder beam reinforcement program at the clear distance of 150 mm;unilateral reinforcement method was used in the lower shoulder beam reinforcement plan with the clear distance of 120 mm.