垫板加强圆主管和支管T形相贯节点抗拉性能研究

Study on tensile performance of doubler plate reinforced T-joints with circular chord and brace

为了研究垫板对圆主管和支管T形相贯节点的加强效果及垫板宽度对相贯节点抗拉性能的影响,对两个垫板宽度不同的T形相贯节点和一个未加垫板T形相贯节点进行了试验研究和有限元分析。试验中,主管两端固定,在支管端部施加竖向位移,研究比较了3个T形节点试件极限抗拉承载力、变形和破坏模态及垫板加强效果。并利用有限元分析软件Abaqus对试件进行了有限元模拟,承载力、变形等分析结果与试验吻合较好。通过研究表明:①在主管和支管之间设置垫板改善了普通相贯节点的应力集中现象,提高了节点的抗拉承载力和结构延性;②合理选择垫板几何尺寸能够使主、支管和垫板共同发挥作用承担外荷载,但垫板宽度参数对节点的受力性能影响较小;③通过试验和有限元应力应变分布分析,探明了节点破坏的机理。

To study the strengthen characteristics and tensile bearing capacity of doubler plate reinforced circular tubular T-joint, two tubular T-joints with different doubler plate width parameter and one tubular T-joint without doubler plate are studied by using experimental and finite element analysis methods. In the experimental study, chord boundary condition is fixed on both ends, displacement-controlled load is applied to the end of the brace, and a comparison of 3 typical T- joints is conducted on the ultimate tensile bearing capacity, deformation, failure modes and reinforcing performance of doubler plate. The finite element software Abaqus is adopted to simulate the experimental work. The analysis results coincide well with test results on the bearing capacity, deformation and so on. Based on these studies, the following conclusions can be drawn： 1 ） the utilization of doubler plate between chord and brace can improve the stress concentration of the ordinary tubular joint. In T-joints, the utilization of doubler plate can also improve the tension bearing capacity and the ductility. 2） Reasonable geometry dimension of doubler plate can make the chord, brace and doubler plate work together to bear the external load. On the other hand, the doubler plate width parameter has little effect on the stiffness and bearing capacity of the reinforced T-joints. 3 ） Based on the stress and strain distributions obtained from the experimental and finite element analysis, the failure modes of T-joints strengthened with doubler plate can be ascertained.