Performance of Steel Girder Joints making use of Higher Strength Concrete

对高强混凝土连接钢梁节点的性能进行了研究。所考虑的节点为端板式混合(钢-混凝土)连接。进行了实验和分析研究，以考察其性能，验证其实用性，并制定设计程序。主要研究成果如下：1.对组合梁连接的钢筋混凝土节点进行了试验研究。结果表明，采用这种连接方式可以获得正弯矩作用下的延性性能。2.建立了混凝土材料的本构模型。在该模型中，可以处理材料中的多个裂纹。编制了非线性有限元分析程序。3.对节点进行了二维有限元分析。研究发现，端板的刚度对钢筋混凝土砌块的受力性能影响不大。研究发现，端板的局部变形可能会对整体结构性能产生影响。4.节点的强度取决于RC砌块的强度或端板的强度。如果端板具有足够的刚性，则RC理论可以合理地评估节点的抗弯和抗剪强度。5.梁的相对转动由RC块内的转动和端板局部变形引起的不连续角组成。6.对包含端板式RC节点的多个组合梁试件进行了试验。修改了连接的细节，以减少先前试验中观察到的端板的局部变形。试验结果表明，改造效果较好。7.采用钢筋混凝土节点在多梁试件上搭建了一座巨型横梁。结果表明，侧梁可以有效地进行荷载分配。通过试验对有效宽度和有效截面进行了检验。

Performance of the connection which joined steel girders through high strength concrete was studied. The connection considered was of endplate type mixed (steel-to-concrete) connection. Experimental as well as analytical studies were carried out to investigate the performance, to verify its practicability, and to develop design procedure. Results of the research are summarized below :1.Experimental studies were carried out on the RC connection which joined composite girders. It was found that ductile behavior under positive moment could be obtained by the connection used.2.Constitutive model for concrete materials was developed. In the model, multiple cracking in the materials could be treated. The model was coded for a nonlinear Finite Element analysis program.3.Two dimensional Finite Element analyzes of the connections were carried out. It was found that the rigidity of the endplate could not significantly affect on the behavior of RC block. It was found that local deformation of the endplate might affect on the whole structural behavior.4.The strength of the connection depends on the strength of RC block or that of the endplate. Bending and shear strength of the connections can be reasonably evaluated by RC theory if the endplate is sufficiently rigid.5.Relative rotation of girders consists of the rotation in RC block and discontinuous angle due to local deformation of the endplate.6.Multi-composite-girder specimen which included endplate type RC connection was tested. Details of the connection was modified so as to reduce local deformation of endplate observed previous tests. Test results showed modification was quite satisfactory.7.RC connection used in the multi-girder specimen constructed a massive lateral beam. It was found that the lateral beam could be effective for load distribution. Effective width and section were also examined through the test.