上海体育馆钢结构网架拆除过程的数值模拟分析

Numerical Simulation of Demolition Process of Steel Grid Roof of Shanghai Stadium

以上海体育馆为例,开展了大型体育场馆钢结构网架拆除过程的有限元模拟分析。采用商业有限元软件ABAQUS建立精细化有限元分析模型,通过生死单元法模拟杆件的拆除过程,根据计算结果揭示网架结构中各杆件应力和竖向挠度的变化规律。开展了网架中部支座类型和支座间距的参数分析,并根据方差分析结果确定拆除过程中网架最大挠度的关键影响因素。有限元分析结果表明,拆除前靠近支撑处的竖向腹杆应力较大,超过了上下弦杆;随着拆除的不断进行,靠近拆除部位的腹杆应力有所增加,且靠近拆除部位的杆件竖向挠度有所增加;支座间距增大后,拆除后期腹杆的应力显著增加,该种工况下极容易出现危险点。方差分析结果表明,支座间距对拆除过程中网架结构最大挠度的影响最大,而支座类型的影响相对较小。在实际拆除过程中,应重点检查支座的数量和有效性,以确保消除潜在的危险点。

Numerical simulation of demolition process of steel grid roof of large-scale stadium was conducted based on an example of the Shanghai Stadium.Finite element model of the steel grid of the Shanghai Stadium was established by using software ABAQUS.Method of killing activating elements was applied to simulate the demolition process of steel members.Evolution of stress and vertical deflection of each member was revealed according to the calculation results.Parametric study was carried out to analyze the effects of type and distance of the supports.Key influencing factors of the maximum deflection of the grid during the demolition process were determined according to the results of variance analysis.FEM calculation results indicated that the vertical web members near the support before removal had a larger stress,which exceeded the upper and lower chords.With the continuous progress of the demolition,the stress of the web rod near the demolition site had increased,and the vertical deflection of the rod near the demolition site had increased.After the support spacing was increased,the stress of the web rod in the later stage of dismantling increased significantly,and dangerous points were prone to appear under such working condition.The results of variance analysis showed that the distance between the supports had the greatest influence on the maximum deflection of the grid structure during the demolition process,while the influence of the support type was relatively small.In the actual demolition process,the number and effectiveness of the supports should be emphatically checked to ensure that potential dangerous points are eliminated.