高原地区大跨度空间钢结构日照温度应力分析

Study on Sunshine Temperature Stress of Long-Span Space Steel Structure in Plateau Area

基于ASHRAE晴空模型和高原强辐照参数,利用有限元法对拉萨某大型医院项目中的大跨度空间钢结构日照温度应力展开分析。结果表明:在14:00,箱型杆件迎光面温度与气温之差达到最大值37.5℃;在15:00,箱型杆件最高温度为65.6℃,日照温度场具有明显的非均匀性和时变性,建议高原地区的大跨度空间钢结构避免在14:00~16:00施工成型。此外,靠近支座的杆件因多余约束温度应力值较大,最大压应力值已达钢材屈服强度的61%,而日照组合荷载下的最大应力值已达到钢材屈服强度的73%。在高原大跨度空间钢结构设计中,应考虑日照温度应力,且日照组合荷载应按控制荷载计算。

Based on ASHRAE clear sky model and plateau strong irradiation parameters,the sunshine temperature stress of long-span space steel structure in a large hospital project in Lhasa is analyzed by finite element method.The results show that at 14:00,the difference between the light facing surface temperature and the air temperature of the box member reaches the maximum value of 37.5℃;At 15:00,the maximum temperature of the box member is 65.6℃,and the sunshine temperature field has obvious non-uniformity and time variability.It is suggested that the long-span space steel structure in the plateau should not be formed during 14:00~16:00.In addition,the maximum compressive stress of the member near the support has reached 61%of the yield strength of the steel due to the large excess restraint temperature stress,while the maximum stress under the combined sunshine load has reached 73%of the yield strength of the steel.In the design of long-span space steel structure in plateau,the sunshine temperature stress should be considered,and the sunshine combined load should be calculated according to the control load.