Establishment of Analytical Methodology for Mechanical,Characteristics of Steel-Concrete Hybrid Structures

(1)编制了钢梁与钢筋混凝土桥墩刚性连接的混合结构有限元分析程序。该程序假定混凝土为均质材料，采用考虑应变软化的Mohr-Coulomb破坏准则。为了严格处理混凝土与钢筋或钢板之间的粘结现象，在已有模型的基础上发展了粘结单元，并将其纳入程序。特别是，混凝土与钢板之间的粘结单元可以表现出滑移和剥落现象。(2)分析结果与试验结果的对比表明，所开发的程序能够准确地跟踪到大变形区的性能。(3)对实际规模的混合结构的分析表明，除非采取一些特殊措施，否则上部结构的大部分荷载将传递到节点及其附近，几乎不向横向分布。(4)在分析的基础上，建立了可以作为设计工具的压杆和拉杆模型。

(1) A FEM program was developed to analyze the mechanical behavior of hybrid structures in which steel girders are rigidly connected to RC pier. In this program, concrete was assumed as homogeneous material, and Mohr-Coulomb's failure criterion was adopted considering strain softening. In order to treat bonding phenomena between concrete and reinforcing bar or steel plate rigorously, bonding elements were developed based on the previously proposed models and incorporated into the program. In particular, the bonding element between concrete and steel plate can express slip and exfoliation phenomena. The developed program can be applied to composite structures in general.(2) Comparison of analysis with experimental results showed that the developed program can trace the behavior accurately up to large deformation region.(3) Analysis on the hybrid structures of actual scale showed that, unless some special measures are taken, most of the load from super structure is transferred to the connection and its vicinity, hardly distributing to the lateral direction.(4) A strut and tie model, which can analyze the behavior more simply and can be used as design tool, was developed based on the analysis.