Q345级大圆孔高强度螺栓连接承压性能研究和设计建议

目的研究大圆孔高强度螺栓的受力性能和破坏模式，为此类高强度螺栓连接提供设计依据．方法利用经过验证的有限元模型，采用通用有限元软件ANSYS对含大圆孔承压型高强度螺栓连接进行分析，并对比欧洲规范和美国规范关于大圆孔的设计方法．结果欧洲规范是在原设计公式的基础上乘折减系数0．8；而美国钢结构规范中扩大孔则是套用原公式，标准孔和扩大孔带入不同的栓孔至板边缘净距，折减系数约为0．9，欧洲规范更加偏保守．有限元计算结果表明按照美国规范计算有部分连接偏于不安全，可能是与对破坏模式的预测不符造成的．结论根据有限元的计算结果，扩孔后螺栓连接的破坏模式没有发生变化，大圆孔承压设计值折减系数介于0．8-1．0，参考美国规范和欧洲规范中对高强度螺栓扩孔折减系数的规定，可偏保守的取0．8．

Investigation and Proposed Design Rules on Bolted Connection with Oversized Holes

In order to study mechanical properties and failure mode of bolted connection with oversized holes, a three-dimensional finite element model was established using the software ANSYS to investigate the design method of these connections. A study on comparisons with EC3, ANSI-AISC 360 -10 and chinese steel design code was also performed. For bolted connection with oversized holes, EC3 provides a reduction factor 0.8 based on the original design formula, and ANSI - AISC 360 -10 suggests using the original formula with different spacing between hole and plate edge. The reduction factor of ANSI-AISC 360 - 10 is about 0. 9. The results of FEM show that the predictions based on ANSI-AISC 360 - 10 for some connections tend to be not safe ,but EC3 is more conservative. Results also show that the failure mode is not changed and the reduction factor is between 0. 8 and 1.0. Referring to EC3 and ANSI-AISC 360 - 10, a relatively conservative reduction factor should be 0. 8.