主讲人：张义霞 博士 澳大利亚 新南威尔大学 堪培拉校区 高级讲师
 Dr Y.X. (Sarah) Zhang, Senior Lecturer, UNSW Canberra, at the Australian Defence Force Academy, ACT, Australia
题  目：Nonlinear finite element analyses of FRP-strengthened concrete slabs using two new composite plate elements with bond-slip effect
时  间：2014年5月16日（星期五）下午3:00
地  点：七号楼201学术报告厅
       欢迎广大师生参加 ！
 
                                  土木与交通学院
                           亚热带建筑科学国家重点实验室
                                    2014年4月30日

主讲人介绍：
    张博士现为澳大利亚新南威尔士大学堪培拉校区工程与信息技术学院高级讲师。她于1992年和1995年分别获得天津大学工程力学学士学位及固体力学硕士学位。2001 年张博士获得香港大学结构工程博士学位。博士毕业后，她曾先后在澳大利亚昆士兰大学、韩国浦项工科大学及澳大利亚新南威尔士大学做博士后研究员。2005年她被新南威尔士大学聘为土木工程讲师，并在2009年晋升为高级讲师。
    张博士多年来一直致力于高等有限元方法及工程结构非线性有限元分析及模拟。近年来特别集中于对结构在极限载荷（包括火载荷、冲击及爆破载荷、周期性循环载荷等）下的行为研究。自2004年以来，张博士的研究兴趣还扩展到发展新型绿色及可持续性的纤维加强水泥基建筑材料，既具有抗冲击及爆破能力的纤维加强的高性能水泥基的建筑材料。她利用数值方法、解析方法及实验方法对材料的机械性能及结构行为从微观到宏观进行全方位的研究。
    自1999年，张博士在国际期刊及国际会议上发表了120余篇学术论文，其中50多篇发表在计算力学、复合结构及结构工程等领域最权威杂志上。她自2009年起担任国际杂志International Journal of Recent Patents in Mechanical Engineering的副主编，2011年开始为International Journal of Composite Materials 的编委会成员。她是多个国际会议的顾问委员会及国际技术委员会成员。她是近20个国际杂志的审稿人，其中包括计算力学、复合结构及结构工程等领域最权威杂志。她是国际计算力学学会、澳大利亚计算力学学会、国际FRP 在建筑中的应用国际协会、澳大利亚复合结构学会及国际防护结构学会的会员。

报告概要
    FRP由于其高强度/密度比及很好的抗腐蚀能力，已被广泛用于土木工程结构的加强和修复。实验研究表明，FRP 的剥离（debonding）是FRP加强混凝土板的主要失效形式。因此，为了更准确的模拟此类结构的结构行为及失效模式，在有限元分析中应该考虑bond-slip 的影响。但是，大多数值研究基于理想粘结的假设，忽略了bond-slip 对结构行为的影响。迄今为止，几乎没有一个简单有效地考虑了bond-slip效果的有限元模型可以用于模拟FRP 加强混凝土板。
    在此研究中，我们发展了两个新的8节点、48自由度考虑bond-slip 的复合层和矩形板单元， 即单元CPEB-1 和 CPEB-2。这两个单元能在一个单元里同时模拟混凝土、钢筋加强、粘结层及FRP 层。在单元 CPEB-1 中，零厚度的界面单元用于连接混凝土及FRP 层以模拟bond-slip。 而在CPEB-2单元中, bond-slip 假设发生在一个具有一定厚度的层内，混凝土和粘结层通过此层来连接。新单元基于Mindlin-Reissner 板理论，Timoshenko’s 复合梁函数用来代表弯曲行为，一个具有旬转自由度的四边形等参元平面位移函数用来模拟平面行为。有限元模型考虑了几何非线性及材料非线性。通过计算结果和从其他文献结果的对比验证了单元的有效性及计算精度。 这两个单元的计算结果也进行了对比。
    在此学术报告中，张博士除了将对这两个单元进行详细地介绍，还将简要介绍其研究团队的其他研究活动。作为CSC-PHD 项目的联络负责人，她也将介绍在UNSW Canberra 的奖学金情况及申请过程。

张义霞  博士的联系方式
Dr Y.X. (Sarah) Zhang
School of Engineering and Information Technology, UNSW Canberra, at the Australian Defence Force Academy, ACT, 2600, Australia
Email: y.zhang@adfa.edu.au; Tel: 612-62688169 (Australia); 86-15919633500 (China)

Brief Biography of Dr Y.X. Zhang
Dr. Zhang is a Senior Lecturer in Engineering in School of Engineering and Information Technology at the University of New South Wales, Canberra, Australia.
She obtained her Bachelor degree on Engineering Mechanics and Master degree on Solid Mechanics from Tianjin University in 1992 and 1995 respectively, and PhD on Structural Engineering from the University of Hong Kong in 2001.
She worked as a Postdoctoral research fellow in the University of Queensland, Pohang University of Science and Technology, South Korea and the University of New South Wales since 2001 to 2005. She started her academic career from 2005 working as a Lecturer on Civil Engineering in the University of New South Wales and was promoted to be Senior Lecturer in 2009.
Her expertise is on the development of advanced finite element method and nonlinear finite element analysis and modelling of engineering structures especially under extreme loadings such as fire loading, impact and blast loading. She has been working on the research of composite materials including construction and building materials and structures since 2004. Her main focuses are on the characterization of mechanical behaviour of composite materials by experimental and numerical methods and simulation of structural behaviour of composite structures.
Dr. Zhang has published over 120 research articles in international journals and conferences since 1999 with over 50 published in leading international journals on Computational Mechanics and Composite Structures. She is the Associate Editor of International Journal of Recent Patents in Mechanical Engineering since 2009 and the editorial board member of International Journal of Composite Materials since 2011. She is an advisory board member and international technical committee member of several international conferences. She has been a frequent reviewer for up to 20 international journals including the topic journals in the area of Computational Mechanics and Composite materials and structures. She is a member of International Association for Computational Mechanics, Australian Association of Computational Mechanics, International Institute for FRP in Construction (IIFC), Australian Composite Structures Society, and International Association of Protective Structures (IAPS) and Australian Chapter.

Abstract:
Fibre reinforced polymers (FRPs) have been extensively to strengthen civil engineering structures due to its high ratio of strength to mass density, high electrochemical corrosion resistance, etc. FRP debonding has been demonstrated to be the dominant failure for FRP-strengthened concrete slabs from laboratory tests. Therefore, it is of great significance to include bond-slip effect in finite element analyses of FRP-strengthened concrete slabs so as to model the structural behaviour and failure behaviour accurately. However a perfect bond between concrete and FRP has been assumed in most of the numerical studies of FRP-strengthened concrete slabs, and so far, very few finite element models, which consider the bond-slip effect between concrete and the strengthened FRP have been developed for analyses of FRP-strengthened concrete slabs.
In this research, two new 8-node, 48-DOF composite layered rectangular plate elements with bond-slip effect named as element CPEB-1 and CPEB-2 are developed. The new elements are integrated elements with the concrete represented by a serial of concrete layers, while the steel reinforcements, adhesive layer and externally reinforced FRP treated as equivalent smeared layers.  In order to include the bond-slip effect, in element CPEB-1, a zero thickness interfacial element is used to connect concrete and FRP layer and to model the debonding between concrete and FRP layer. While in element CPEB-2, the bond-slip is assumed to occur within a smeared layer with real thickness, which connects the concrete tensile zone with the adhesive layer. The new elements are developed based on the Mindlin-Reissner plate theory, and Timoshenko’s composite beam functions and the plane displacement interpolation function for a quadrilateral isoparametric element with drilling DOF are used to represent the bending and membrane behaviour. Both geometric nonlinearity and material nonlinearity are included in the finite element models. The proposed elements are validated by comparing the computed results from the current finite element models with those obtained from literature, and the computed results from the two elements are also compared.
Dr. Zhang will introduce the two news composite layered plate elements recently developed in this seminar. She will introduce briefly the current research activities in her research group.  In the meanwhile, as the coordinator for the CSC-PHD program, she will also present the scholarship opportunities in UNSW Canberra and the application process.