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类型 基础研究 预答辩日期 2018-02-26
开始(开题)日期 2014-01-13 论文结束日期 2017-12-15
地点 四牌楼校区进香河路35号智能交通馆2楼会议室 论文选题来源 973、863项目     论文字数 10 (万字)
题目 GFRP桥面板胶接界面力学性能研究
主题词 GFRP桥面板,胶接界面,界面应力分布,不均匀分布特性,I型断裂韧性
摘要 G胶接接头是GFRP桥面板的关键部位之一,它决定了桥面板的整体力学性能以及桥面板与主梁之间的组合行为。实际桥梁工程中,GFRP桥面板胶接接头常暴露出脱粘、剥离以及裂纹等病害,严重影响了GFRP桥面板的使用性和耐久性。为提升GFRP桥面板的工作性能,推动GFRP桥面板的工程应用,需对其胶接接头力学性能进行系统研究。 本文采用理论研究、数值仿真与模型试验相结合的方法,深入揭示了复合材料单搭接胶接界面应力分布特征、DCB试件裂纹尖端能量释放率不均匀分布特性及其对I型断裂韧性的影响,为GFRP桥面板胶接接头强度设计与抗裂设计提供了理论分析模型和实用方法。主要研究工作与结论包括: (1) 通过计入拉-弯耦合效应与搭接区域几何大变形效应的影响,给出了适用于分析非平衡复合材料单搭接接头端部弯矩因子的一维非线性模型,该模型计算精度较高;基于提出的一维模型,开展关于几何参数与材料属性的参数分析,揭示了非平衡单搭接接头端部弯矩因子的变化规律,明确了非平衡单搭接接头经典理论模型的适用范围。同时,给出了非平衡长、短搭接接头的临界值,据此推导得到了判别非平衡长、短搭接接头的计算公式。 (2) 提出了适用于确定非平衡复合材料单搭接接头胶层界面应力分布的二维非线性模型,该模型考虑了拉-弯耦合效应与搭接区域几何大变形效应的影响、具有较高计算精度。利用文中二维非线性模型研究了拉伸荷载与材料属性对胶层界面应力分布的影响。研究结果表明,搭接区域几何大变形对胶层界面应力分布的影响不可忽略;胶层界面应力集中程度与上、下搭接板的抗弯刚度差异相关。 (3) 提出了适用于分析DCB试件裂纹尖端能量释放率不均匀分布特性的等效板模型。基于经典Kirchhoff板理论与Rayleigh-Ritz法,推导得到了不均匀分布系数与变异系数的解析表达式,以上表达式计算精度均较高。采用等效板模型与虚拟裂纹闭合法,定量研究了双材料DCB试件不均匀分布系数,该系数可表示为分别由双材料DCB试件的上、下搭接板组成的单材料DCB试件裂纹尖端不均匀分布系数的平均值。 (4) 揭示了裂纹萌生与扩展过程中DCB试件不均匀分布系数与裂纹长度偏差的变化规律,明确了不均匀分布特性对I型断裂韧性的影响,据此修正了ASTM D 5528-01e3等既有规范中计算DCB试件I型断裂韧性的三种经典梁模型。给出了适用于计算裂纹萌生与扩展过程中裂纹长度偏差的实用计算公式,该公式形式简洁、计算精度较高。 (5) 提出了一种含曲线形预设裂纹尖端的改进型DCB试件,该新型试件的能量释放率沿其曲线形预设裂纹尖端均匀分布。与含直线形预设裂纹尖端的传统型DCB试件相比,改进型试件确定的I型断裂韧性更合理且其计算工作更简便。为便捷且准确地选用具有能量释放率均匀分布特性的曲线形预设裂纹尖端形状,给出了形式简洁的实用计算公式。 (6) 基于多尺度有限元模型与虚拟裂纹闭合法,定量研究了粘结界面裂纹长度对钢-GFRP组合梁桥负弯矩区GFRP桥面板力学性能的影响,评估了各工况条件下粘结界面裂纹断裂行为。
英文题目 Research of Mechanical Properties for Adhesive Interface in GFRP Bridge Deck
英文主题词 GFRP bridge deck, adhesive interface, interfacial stress distributions, feature of non-uniformity distribution, mode-I fracture toughness
英文摘要 Adhesively bonded joint is one of the key parts of GFRP bridge deck. The whole mechanical properties of the GFRP bridge deck and the composite action between GFRP bridge deck and main girder depend on the adhesively bonded joint. In bridge engineering, several failures (e.g., delamination and cracking) often occur at the adhesively bonded joint of GFRP bridge deck, which have an adverse effect on usability and durability. In order to enhance service behavior of the GFRP bridge deck and promote the application in engineering, systematic research of the mechanical properties for adhesively bonded joint is necessary to perform. The characteristic of interfacial stress distributions for composite single-lap joint (SLJ), feature of non-uniformity distribution of double cantilever beam (DCB) and its effects on mode-I fracture toughness were intensively studied with theoretical analysis, numerical simulation and model test. The aforementioned works can provide theoretical models and practical methods for strength design and anti-fracture design of adhesively bonded joint in GFRP bridge deck. Details of the present study are summarized as follows: (1) A one-dimensional nonlinear model with high accuracy for determining edge moment factor of unbalanced composite SLJ was provided with incorporating the effects of bending-tension coupling and large deformation in overlap. The parametric analyses concerning geometrical parameters and material properties were performed with the on-dimensional model. The varying pattern of the edge moment factor and applicability of the existing models for unbalanced SLJ were studied. Meanwhile, the critical value and theoretical formulas were provided for determining long and short unbalanced SLJ. (2) A two-dimensional model with high accuracy for determining interfacial stress distributions of unbalanced composite SLJ was developed by considering the effects of bending-tension coupling and large deformation in overlap. Based on the present two-dimensional model, the effect of the tensile load and material properties on adhesive stress distributions was studied. The results indicated that the effect of the large deformation in overlap region on adhesive stress distributions can’t be neglected. And the stress intensities of adhesive stresses are related with the difference between the flexural stiffness of upper and lower adherends. (3) An equivalent plate model was developed for the determination of feature of non-uniformity for energy release rate (ERR) distribution in DCB specimen. The analytical formulas with high accuracy for non-uniformity and variation coefficients were obtained with Kirchhoff theory and Rayleigh-Ritz method. The equivalent plate model and virtual crack closed technique (VCCT) were used to analyze the non-uniformity coefficients for the bi-material DCB specimen, which is equal to the average value of the non-uniformity coefficients for the two symmetric DCB specimens composed of upper and lower adherends of biomaterial DCB specimen, respectively. (4) The varying patterns of non-uniformity coefficient and deviation of crack length for DCB specimen in initiation and propagation processes and its effects on mode-I fracture toughness were studied. Then, the three classical beam models in existing codes (including ASTM D 5528-01e3) for determination of mode-I fracture toughness were modified. The practical formulas with compact form and high accuracy for determing deviation of crack length in initiation and propagation processes were developed. (5) An improved DCB specimen with curved pre-cracked front was provided. The ERR distribution along the curved pre-cracked front is uniform. Compared to the traditional DCB specimen with the straight pre-cracked front, mode-I fracture toughness determined by the improved DCB specimen is more reasonable and its calculation is more simpler. A practical formula with compact form for determination of shape function of curved pre-cracked front was provided. (6) The effect of crack length of adhesive interfacial crack on mechanical properties of GFRP bridge deck in negative moment region of steel-GFRP composite bridge was investigated with multi-scale finite element model and VCCT. And the fracture behavior of adhesive interfacial crack under some load cases was evaluated.
学术讨论
主办单位时间地点报告人报告主题
瑞士洛桑联邦理工大学CCLab 2016.10.03 瑞士洛桑联邦理工大学CCLab 蒋正文 Effect of curved crack front on the mode-I fracture toughness of composite DCB specimens with an adhesive layer
瑞士洛桑联邦理工大学CCLab 2016.11.28 瑞士洛桑联邦理工大学CCLab 蒋正文 Improved two-dimensional model for unbalanced composite single-lap joint considering the large deflection effect
瑞士洛桑联邦理工大学CCLab 2017.02.27 瑞士洛桑联邦理工大学CCLab 蒋正文 Evaluation of fracture behavior in negative moment regions of a continuous steel-GFRP composite bridge
瑞士洛桑联邦理工大学CCLab 2017.04.24 瑞士洛桑联邦理工大学CCLab 蒋正文 A modified DCB specimen with curved crack front for mode I test
瑞士洛桑联邦理工大学CCLab 2017.06.19 瑞士洛桑联邦理工大学CCLab 蒋正文 Effect of curved delamination front on R-curve of DCB specimen
东南大学 2013.10.05 东南大学四牌楼校区道桥试验室502 范文理 对钢管混凝土拱桥结构病害的思考
东南大学交通学院波形钢腹板组合桥梁课题组 2014.06.07 东南大学四牌楼校区道桥试验室502 蒋正文 ANSYS实体建模型
东南大学交通学院波形钢腹板组合桥梁课题组 2015.08.12 东南大学四牌楼校区道桥试验室502 蒋正文 子模型法
     
学术会议
会议名称时间地点本人报告本人报告题目
第19届复合材料结构国际会议 2016.09.06 葡萄牙波尔图 Analytical solutions for non-uniformity of energy release rate of orthotropic DCB specimens with an adhesive layer
东南大学交通学院波形钢腹板组合桥梁课题组 2017.09.05 东南大学四牌楼校区道桥试验室502 GFRP桥面板胶接接头力学性能研究
     
代表作
论文名称
Determination of mode-I fracture toughness and non-uniformity for GFRP double cantilever beam specim
Effect of curved delamination front on mode-I fracture toughness of adhesively bonded joints
Two dimensional analysis for an adhesively bonded composite single-lap joint based on flexible inter
Geometrically nonlinear analysis for unbalanced adhesively bonded single-lap joint based on flexible
Calculation of energy release rate for adhesive composite/metal joints under mode-I loading consider
The use of flexible interface theory for fully coupled nonlinear analysis of balanced adhesive singl
Analytical solutions for non-uniformity of energy release rate of orthotropic double cantilever beam
An alternative solution for the edge moment factors of the unbalanced adhesive single-lap joint in t
Two-dimensional analytical stress distribution model for unbalanced FRP composite single-lap joints
基于分层线性离散模型的FGM板断裂力学分析
结构可靠度分析中的混合模拟法及其应用
基于混合模拟法的连续刚构桥静力可靠度分析
 
答辩委员会组成信息
姓名职称导师类别工作单位是否主席备注
黄侨 正高 教授 博导 东南大学
陈徐均 正高 教授 博导 中国人民解放军陆军大学
艾军 正高 教授 硕导 南京航空航天大学
钱振东 正高 教授 博导 东南大学
王文炜 正高 教授 博导 东南大学
      
答辩秘书信息
姓名职称工作单位备注
胡晓伦 其他 讲师 东南大学