RELIABILITY CHECK ANALYSIS OF EXISTING DESIGN METHOD FOR SINGLE-LAYER SPHERICAL LATTICED DOMES
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摘要: 中国现行的空间结构设计方法仍然采用经验的整体安全系数，未能较好地考虑不确定性因素的影响。该文选取K8型单层球面网壳，对该结构进行整体可靠度分析。建立荷载和结构参数的概率模型，分别采用蒙特卡洛模拟和响应面法，构造结构真实的荷载与抗力极限状态方程，进而采用FORM计算其失效概率和可靠指标。同时对《空间网格结构技术规程》(JGJ 7−2010)提供的设计方法进行校准，基于规程的整体安全系数设计公式生成结构的极限状态方程，并得到其失效概率和可靠指标。分析结果表明：现有规程设计方法偏于保守，过低估计了结构的可靠性，应该基于全概率整体可靠度分析方法对现有设计方法进行修正。Abstract: The existing design method for the spatial structure in Chinese specifications fails in precisely considering the uncertainties of random variables, for taking a rough and experiential global safety factor. The uncertainty of loads and structure are not considered in the existing design method. The kiewitt8 single-layer latticed dome structures are selected for a global stability analysis. The probabilistic models of loads and structures are built, the Monte Carlo Simulation (MCS) and Response Surface Method (RSM) are both carried out for constructing the limit state equations of real loads and structural resistance, and then the failure probability and reliability index of the structure are computed based on FORM. The design method in <Technical specification for space frame structures> (JGJ 7−2010) is calibrated, the structural limit state equations are constructed based on the global safety factor design formula in the specification, and then the failure probability and indexes of reliability of structures are obtained. The analysis results show that: the design method in existing specification underestimates the structural reliability, and the design method should be revised based on full probability global reliability analysis method.
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表 1 模型参数
Table 1. Parameters of the model
几何参数 K8网壳 跨度L/m 40 矢跨比f/L 1/5 径向/环向杆件/mm Φ121×3.5 斜杆/mm Φ114×0.3 钢材 Q235 
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表 2 不确定性量概率分布参数
Table 2. Parameters of probability distribution function for uncertainty variables
不确定性参数 概率分布模型 均值 变异系数 钢材屈服强度fy/MPa 对数正态 251.45 0.081 弹性模量E/MPa 对数正态 2.06×105 0.050 泊松比μ 对数正态 0.3 0.050 恒荷载G/(kN/m2) 正态分布 1.61 0.070 活荷载L/(kN/m2) 极值I型 0.322 0.357 杆件1外径R1/mm 正态分布 0.146 0.020 杆件1壁厚T1/mm 正态分布 0.005 0.020 杆件2外径R2/mm 正态分布 0.14 0.020 杆件2壁厚T2/mm 正态分布 0.006 0.020 节点偏差w/mm 正态分布 0 −
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表 3 各参数灵敏度
Table 3. The sensitivity of parameters
参数 灵敏度 标准占比/(%) 钢材屈服强度fy 9.2558×10−1 66.56 杆件1壁厚T1 2.5227×10−1 18.14 杆件1外径R1 2.1274×10−1 15.30 杆件2壁厚T2 3.9210×10−2 − 杆件2外径R2 4.9946×10−2 − 弹性模量E −9.3117×10−3 − 泊松比μ 7.5533×10−2 − 节点偏差w −9.2745×10−2 −
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表 4 不同工况可靠指标
Table 4. Reliable indexes of different conditions
工况 基于结构实际所受
荷载构造响应面基于规程规定的整体
安全系数构造响应面可靠指标β 4.46 0.290 失效概率pf 3.94×10−6 0.385
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[1] 陈昕. 空间网格结构全过程分析及单层鞍形网壳的稳定性[D]. 哈尔滨: 哈尔滨建筑工程学院, 1990.Chen Xin. The whole process analysis of spatial grid structures and stability of single saddle shells [D]. Harbin: Harbin Institute of Architectural Engineering, 1990. (in Chinese) [2] Holzer S M, Waston L T. Stability analysis of lamella domes: long span roof structures [M]. New York, NY, USA: Committee on Special Structures of the Committee on Metals of the Structural Division, American Society of Civil Engineers, 1981: 179 − 209. [3] Fan F, Cao Z, Shen S. Elasto-plastic stability of single-layer reticulated shells [J]. Thin- Walled Structures, 2010, 48(10): 827 − 836. [4] 李元齐, 沈祖炎. 大跨度拱支网壳结构体系及静力性能研究[J]. 浙江大学学报(工学版), 2001, 35(6): 645 − 650. doi: 10.3785/j.issn.1008-973X.2001.06.013Li Yuanqi, Shen Zuyan. Arch-supported reticulated shell structures and their mechanical behaviors [J]. Journal of Zhejiang University (Engineering Science), 2001, 35(6): 645 − 650. (in Chinese) doi: 10.3785/j.issn.1008-973X.2001.06.013 [5] 郭佳民, 董石麟, 袁行飞. 随机缺陷模态法在弦支穹顶稳定性计算中的应用[J]. 工程力学, 2011, 28(11): 178 − 183.Guo Jiamin, Dong Shilin, Yuan Xingfei. Application of random imperfection mode method in stability calculation of super-dome [J]. Engineering Mechanics, 2011, 28(11): 178 − 183. (in Chinese) [6] 王多智, 李文亮, 支旭东. 考虑有檩体系屋面系统的网壳结构静力稳定性分析[J]. 工程力学, 2017, 34(增刊): 71 − 77, 98. doi: 10.6052/j.issn.1000-4750.2016.03.S005Wang Duozhi, Li Wenliang, Zhi Xudong. Static stability analysis of reticulated shell with purlin roofing system [J]. Engineering Mechanics, 2017, 34(Suppl): 71 − 77, 98. (in Chinese) doi: 10.6052/j.issn.1000-4750.2016.03.S005 [7] 张延年, 王元清, 石永久. 大跨度轻钢结构风雪灾害原因与实例分析[J]. 沈阳建筑大学学报(自然科学版), 2011, 27(2): 272 − 280.Zhang Yannian, Wang Yuanqing, Shi Yongjiu. The analysis of cause and of snowstorm disaster of large-span light steel structure [J]. Journal of Shenyang Jianzhu University (Natural Science), 2011, 27(2): 272 − 280. (in Chinese) [8] 何政, 朱振宇, 刘婷婷. 单层球面网壳考虑一致倒塌概率的倒塌安全储备分析[J]. 工程力学, 2016, 33(10): 218 − 225. doi: 10.6052/j.issn.1000-4750.2015.03.0225He Zheng, Zhu Zhenyu, Liu Tingting. Collapse safety margin analysis of single-layer spherical lattice shells considering consistent collapse probability [J]. Engineering Mechanics, 2016, 33(10): 218 − 225. (in Chinese) doi: 10.6052/j.issn.1000-4750.2015.03.0225 [9] JGJ 7−2010, 空间网格结构技术规程[S]. 北京: 中国建筑工业出版社, 2010.JGJ 7−2010, Technical specification for space frame structures [S]. Beijing: China Architecture & Building Press, 2010. (in Chinese) [10] JGJ 61−2003, 网壳结构技术规程[S]. 北京: 中国建筑工业出版社, 2003.JGJ 61−2003, Technical specification latticed shells [S]. Beijing: China Architecture & Building Press, 2003. (in Chinese) [11] 范峰, 曹正罡, 马会环, 等. 网壳结构弹塑性稳定性[M]. 北京: 科学出版社, 2015: 81 − 83.Fan Feng, Cao Zhenggang, Ma Huihuan, et al. Elasto-plastic stability of reticulated shells [M]. Beijing: Science Press, 20015: 81 − 83. (in Chinese) [12] 鲜晓东. 基于整体可靠度的单层球面网壳静力稳定性概率设计研究[D]. 哈尔滨: 哈尔滨工业大学, 2017.Xian Xiaodong. Research of probabilistic design methods based on global reliability for static stability of single-layer latticed domes [D]. Harbin: Harbin Institute of Technology, 2017. (in Chinese) [13] 钟杰. 网壳结构的概率地震易损性分析[D]. 哈尔滨: 哈尔滨工业大学, 2016: 63 − 64.Zhong Jie. Probabilistic seismic fragility analysis of reticulated shells [D]. Harbin: Harbin Institute of Technology, 2016: 63 − 64. (in Chinese) -
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