基于空间位形的在役索膜结构有限元模型修正与安全评估  

FINITE ELEMENT MODEL UPDATING AND SAFETY ASSESSMENT OF IN-SERVICE CABLE-MEMBRANE STRUCTURE BASED ON SPATIAL CONFIGURATION

作　　者：丁一凡 刘宇飞[1,2] 樊健生[1,2] 刘家豪 DING Yi-fan;LIU Yu-fei;FAN Jian-sheng;LIU Jia-hao(Department of Civil Engineering,Tsinghua University,Beijing 100084,China;Key Laboratory of Civil Engineering Safety and Durability of China Ministry of Education,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学土木工程系,北京100084 [2]清华大学土木工程安全与耐久教育部重点实验室,北京100084

出　　处：《工程力学》2022年第5期44-54,共11页Engineering Mechanics

基　　金：北京市自然科学基金项目(8192023);国家自然科学基金项目(51725803)。

摘　　要：索膜结构的内力分布与空间位形相互关联,受施工阶段的几何找形与服役阶段的结构损伤、性能退化等影响,在役索膜结构的实际位形与设计状态有所差异,结构的服役性态未知,工程上的安全评估难以操作且并无可靠方法借鉴。该文提出了一种基于空间位形指标的在役索膜结构有限元模型修正方法,以模型中拉索的初始预应力作为优化参数、以结构关键节点坐标的匹配作为模型修正目标函数,通过构建基于结构特征点空间位置信息的目标函数来反映有限元模型与实际结构的吻合度,设计ABAQUS与MATLAB联合仿真优化程序,利用全局搜索和局部优化实现模型修正。现场试验采用三维激光扫描获取在役索膜结构空间位形信息,基于实测数据对有限元模型进行修正。修正后模型与实际结构受力状况更为接近,与索力的实测结果对比表明,有限元模型的索力由修正前最大偏差10%~30%降低至10%以下,验证了方法的有效性与准确度。利用修正后的有限元模型实现了在役索膜结构的安全评估。The internal force distribution of cable-membrane structures is related to the spatial configuration. The actual configuration of a cable-membrane structure in service is different from that in design state due to the geometric shape finding during the construction phase, the structural damage and the performance degradation during service phase. Since the service behavior is unknown, the engineering safety assessment is difficult to operate and there is no reliable method for reference. A finite element model updating method was proposed for in-service cable-membrane structures based on spatial configuration indicators. The initial prestress of the cables in the model is used as the optimization parameter, and the coordinate of the key nodes of the structure is used as the model updating objective function. The objective function based on the spatial location information of the feature points is constructed to reflect the coincidence degree between the finite element model and the actual structure. The ABAQUS and MATLAB co-simulation optimization program is designed, and the model is updated by global search and local optimization. In the field test, 3D laser scanning was used to obtain the spatial configuration information of the in-service cable-membrane structure,and the finite element model was updated based on the measured data.The force of the updated model is closer to the actual structure.The comparison with the actual measurement results of the cable force shows that the cable force of the finite element model is reduced from the maximum deviation of 10%~30%before the correction to within±10%,which verifies the effectiveness and accuracy of the method.The updated finite element model is used to perform the safety assessment of the inservice cable-membrane structure.

关 键 词：索膜结构 有限元模型修正 空间位形 索力 安全评估 三维激光扫描 

分 类 号：TU399[建筑科学—结构工程]