Biography: Dr. Jiang received his PhD in Bridge engineering at Tongji University in 2010. He had two and a half year postdoc research experience at The Hong Kong University of Science & Technology and The University of Georgia after graduation. Now, he is an associate professor at School of highway, Chang’an University. His current research interests focus on numerical simulation of the impact response of infrastructures including vessel impacts and vehicle impacts, as well as the characterization of strength and constitutive modeling of quasi-brittle materials such as rocks and concrete. He has served as an active reviewer for more than 10 international journals (e.g. ACI Structural Journal, ACI Material Journal, Materials & Design, Int. J. Rock Mech. & Mining Sci, Nuclear Engineering and Design) and the technical program committees of several professional conferences/workshops. He also has chaired several international conferences. He has published nearly 30 peer-review journal papers by the first author. Two papers have been listed as Top 25 Hottest Articles in the journals. He is an associate member of ASCE and a member of ISRM.
Topic: Comparison of Two Smeared Crack Approaches to Calibrate an Elasto-plastic Damage Model for Concrete Subjected to Impact Loading
Abstract: Concrete structures are commonly used in civil engineering, ocean engineering, and protective engineering. Carrying out numerical analysis of concrete structures subjected to impact loading is essential to investigate the dynamic performance of structures. In the numerical simulation, effective constitutive models for concrete play a vital role. This research focus on a comparison study on two smeared crack approaches to calibrate an elasto-plastic damage model for concrete subjected to impact loading. The studied model is an advanced constitutive model in LS-DYNA that is able to take account on post-peak strain softening, shear dilation, confinement and strain rate effects of concrete. However it appears to be less popular as many other constitutive models in engineering application due to many material parameters involved in the model formulation which are difficult to calibrate. The input material parameters are given as functions of uniaxial compression strength and the maximum aggregate size of concrete. The obtained parameters can be conveniently used for occasional users with little or no information on concrete in hand. Validations of the applicability of the model with proposed damage parameters against uniaxial tension of concrete specimen as well as falling weight impact tests of reinforced concrete beams are carried out. The results demonstrate that the energy balance model results in severe damage than the fictitious crack model, and generally both models are capable of offering reasonable and robust predictions.
Biography: Dr. Xiang Ping graduated with his PhD from the City University of Hong Kong in 2012. Before his PhD study in City University of Hong Kong in 2009, He had several years working experience as an engineer in industry taking responsibilities for structural analysis and design. He was involved in numerous structural analysis of building structures in Hong Kong. His main research interests and technical expertise are in Steel reinforced concrete structures, Seismic structural design, solid mechanics, meshfree methods, multiscale modeling, nonlocal elasticity, computational mathematics, numerical methods in engineering and structural design. Over the last years, his research in these fields has resulted in refereed international journal papers, including Comput Meth Appl Mech Eng., Int. J. Solids Struct., etc. Currently, he is a Research Associate responsible for research and teaching activities in the City University of Hong Kong.
Topic: Structural Performances of Steel Reinforced Concrete Special Shaped Column-Beam Joints Under Bidirectional Low-Cyclic Reversed Loading
Abstract: Steel reinforced concrete (SRC) T-shaped column-beam structure system has superiorities of both steel reinforced structure and special-shaped column structure. This research focuses on SRC T-shaped column-beam joint design and experimentally investigates seismic behaviors of the proposed joints. Pseudo-static tests are carried out on three SRC T-shaped column-reinforced concrete (RC) beam joints and one RC T-shaped column-RC beam joint. The experiments were conducted under bidirectional low-cyclic reversed loading to simulate realistic loading conditions under earthquake. Hysteresis loops of all the specimens, including load-deflection，moment-rotation and load-shear deformation loops, are plotted for the evaluation of seismic reaction. The working index, ductility coefficient and equivalent viscous-damping coefficient are calculated for comparisons. Meanwhile, the ductility, capacity of energy dissipation, stiffness degradation and the function of steel reinforcement in resisting shear force in the joint core area are intensively studied. Based on experimental results, this research analyzes shear resistant capacity and the inner force transmission in these joints. It is found that the SRC T-shaped column-RC beam joint performs well under seismic; moreover, shear resistant capacity, ductility and reliability are satisfactory. Conclusions derived from this research are useful for engineering practice.