项目名称： 面向混凝土梁桥结构状态评估的非线性有限元模型修正研究

项目编号： No.51508488

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 建筑科学

项目作者： 唐盛华

作者单位： 湘潭大学

项目金额： 20万元

中文摘要： 基于线性有限元模型并采用降低单元刚度模拟结构损伤，对混凝土梁桥进行结构状态评估目前应用较为普遍。然而，结构状态评估势必涉及结构刚度、承载力及混凝土、钢筋应力状态等，由于混凝土结构具有明显的材料非线性特性，导致修正后的线性模型不能准确地对结构当前应力状态、后期性能进行预测，并且，结构刚度变化难以直接评定结构承载能力。项目拟结合结构非线性分析和模型修正方法，设计试验测试混凝土梁不同应力状态、裂缝形态等参数差异下的静力、动力响应；基于试验数据，通过方差分析选择材料本构中敏感参数为待优化参数，由非线性分析计算得到结构的损伤函数，采用响应面方法实现模型修正，建立适用于结构当前状态评估及后期性能预测的非线性静力、动力基准有限元模型；进而通过修正后的静力、动力非线性有限元模型比较，建立混凝土梁桥静力刚度、动力刚度及承载力本构层面的关系。项目研究成果将为基于动力特性的混凝土梁桥结构状态评估提供重要依据。

中文关键词： 混凝土梁桥；结构状态评估；非线性分析；模型修正；动力刚度

英文摘要： At present, based on linear finite element model and the stiffness of the elements is reduced to represent damage is widely used in concrete girder bridge structural condition assessment. However, structural condition assessment will inevitably involves the structure stiffness and bearing capacity, concrete and steel bar stress state, etc., because of the concrete structure has obvious nonlinear material properties, leads to the updated linear model can’t accurately predict stress state and future performance of the structure. Moreover, the change of the structural stiffness is difficult to directly assess the structure bearing capacity. This project will combine structural nonlinear analysis and model updating method, design experimental test static and dynamic respense of concrete beams under different parameters such as different stress state, fracture morphology etc.. Based on the test data, through the analysis of variance, the sensitive material constitutive relationship parameters are chosen as the optimal parameters. The damage function of structure is calculated by the nonlinear analysis and model updating is realized by using the response surface method. Establish nonlinear static and dynamic baseline finite element models for structural condition assessment of the current status and performance prediction of future. And then by comparing the updated static and dynamic nonlinear finite element model, build the relationship of static stiffness, dynamic stiffness and bearing capacity for concrete girder bridge on the constitutive level. The research results of this project will provide an important basis for the structural condition assessment of concrete girder bridge based on dynamic characteristics.

英文关键词： concrete girder bridge;structural condition assessment;nonlinear analysis;model updating;dynamic stiffness