交错桁架-柱装配式节点滞回性能试验研究

Experimental Investigation on Hysteretic Behavior of Staggered Truss-Column Assembled Joints

摘要:

针对交错钢桁架与柱子装配式连接的工程应用和抗震设计需要，设计了三个不同连接构造的节点，试验研究了由上弦杆、斜腹杆和柱子组成的受轴力循环作用的桁架节点滞回性能，试验表明斜腹杆与节点板的焊接部位是薄弱环节，容易开裂破坏。在以上节点的斜腹杆破坏失效后，选择了其中两个节点，继续试验研究了由弦杆和柱子组成的受弯矩循环作用的框架节点滞回性能。分析了这些节点在斜腹杆失效前后的破坏特征、承载力、延性、耗能能力等性能以及不同连接构造细节对这些性能的影响。研究表明受循环轴力的桁架节点具有较高的承载力和初始刚度，但延性、耗能能力一般，弦杆与柱的连接构造形式对节点性能影响不显著；受循环弯矩的框架节点仍具有较高的抗弯承载力和耗能能力，但是弦杆与柱的连接构造形式对节点性能有较大的影响。为了抵抗地震作用，建议交错钢桁架的H形截面弦杆的上下翼缘应与柱子可靠连接，来确保斜腹杆破坏退出工作后弦杆通过抗弯方式传力到柱子，实现强节点的功效。

Abstract:

For the need of engineering application and aseismic design of assembled connection between a staggered steel truss and a column， three kinds of joints were designed with different connection constructions. The hysteretic behavior of chord-web-column truss joints was investigated experimentally under cyclic axial force. It was found that the welded connection between diagonal web member and gusset plate was a weak link， liable to cracking. After the diagonal web member was damaged in the truss joint above， two of the three joints were selected to continue the tests on the hysteretic behavior of chord-column moment frame joints under cyclic bending moment. The performance such as failure feature， load bearing capacity， ductility and energy dissipation as well as influence of connection construction details was analyzed for these joints before and after the diagonal web member was damaged respectively. It is concluded that the truss joints subjected to cyclic axial force has a high loading capacity and initial rigidity， but a general ductility and energy dissipation ability. The chord-column connection configuration has no significant effect on the joint performance. The moment frame joints subjected to cyclic bending moment still has a high bending capacity and energy dissipation ability， but the effect of chord-column connection configuration on the joint performance is significant. In order to resist earthquake action， it is suggested that both the upper and lower flanges of H-section chord member in a staggered steel truss should be connected with the column reliably， which will cause the chord to transfer load to the column by means of bending resistance after the diagonal web member damages and then realize the function of a strong joint.