【摘要】 整体节点是钢桁梁桥的关键局部结构，针对当前在设计分析中存在局部边界条件不明确、计算结果准确度不高等问题，为了提高整体节点计算的准确性，引入多尺度有限元建模方法研究其受力特征及构造设计。首先，基于变形协调原理，针对全桥1个受力复杂的整体节点，运用ABAQUS有限元软件建立多尺度模型，并将其与杆系模型和实测数据进行对比，从位移、应力和界面连接3个方面验证了多尺度模型的有效性。然后，基于多尺度模型讨论了整体节点不同位置的横隔板厚度、腹板厚度对节点应力集中的影响。结果表明：增大中间横隔板厚度对减小节点与横梁连接处应力集中有明显效果，厚度增大1 mm,应力减小值由9.57 MPa降低到2.91 MPa;增大支座边缘横隔板厚度对降低支座处腹板应力集中有较明显效果，应力平均减小幅度为0.8 MPa;增大节点板厚度可以降低节点的应力峰值，应力平均减小幅度为1.85 MPa,且呈近似线性关系。更多还原

【Abstract】 The integral joint is the key local structure of steel truss bridge. At present, there are some problems in the design and analysis, such as unclear local boundary conditions and low accuracy of calculation results. In order to improve the accuracy of integral joint calculation, the multi-scale finite element modeling method is introduced to study its mechanical characteristics and structural design. Firstly, based on the principle of force balance, a multi-scale model is established by using ABAQUS finite element software for a complex joint of the whole bridge, and compared with the bar model and measured data. The effectiveness of the multi-scale model is verified from three aspects of displacement, stress and interface connection. Then, based on the multi-scale model, the effects of diaphragm thickness and web thickness at different positions of the integral joint on the joint stress concentration are discussed. Increasing the thickness of the middle diaphragm has an obvious effect on reducing the stress concentration at the connection between the joint and the beam. When the thickness increases by 1 mm, the stress reduction value decreases from 9.57 MPa to 2.91 MPa. Increasing the thickness of the diaphragm at the edge of the support has an obvious effect on reducing the stress concentration in the web at the support, with an average reduction of 0.8 MPa. Increasing the thickness of the gusset plate can reduce the peak stress of the joint, with an average reduction of 1.85 MPa, which is approximately linear.更多还原