超500MPa级高强钢螺栓连接受剪性能与设计方法研究

Due to the lack of theoretical and experimental study on the shear behavior of bolt connection for high strength steel members, the design and fabrication of bolt connections for high strength steel members are limited. To this end, this project intents to carry out a series of experiments on the mechanical properties and shear behavior of bolt connection of Q550, Q690 and Q890 high strength steels, including tensile and compressive coupon tests, notched round bar specimen test, pre-tensioned single bolt connection test, net cross-section tensile test, bearing resistant test of high strength steel tension splices with one, two or several bolts, and slip factor test. Based on the test result, hydrostatic pressure dependent constitutive model will be developed in 3D space and verified for high strength steel. The parameters of the constitutive model will be calibrated for Q550, Q690 and Q890 steels. In addition, the critical ratios of net cross-section area to gross cross-section area and slip factors for Q550, Q690 and Q890 high strength steels will be determined, respectively. Moreover, numerical model for simulating the behavior of bolt bearing will be established and verified by comparing with the tests. With the verified numerical model, an extensive parametric analysis will be conducted. The effect of steel strength, hole diameter, edge distance, end distance, spacing, number of shear plane, and pretension value of the bolt on the failure mode and ultimate bearing resistance of high strength steel bolt connections will be further investigated and summarized. Finally, the calculation and design methods for the ultimate resistance of Q550, Q690 and Q890 high strength steels bolt connections subjected to shear will be proposed and the corresponding minimum requirements of edge distance, end distance and spacing will be suggested.

限于目前针对高强钢构件螺栓连接受剪性能的理论与试验研究成果较少，尚难以形成系统的设计理论支持高强钢构件的连接设计。本项目拟进行Q550、Q690和Q890高强钢的材料力学性能拉伸与压缩试验、圆棒切口试件拉伸试验、施预紧力单螺栓连接试验、带削弱构件拉伸试验、承压型单、双、多螺栓连接受剪试验和摩擦面抗滑移系数试验；以确定Q550、Q690和Q890高强钢的静水压力相关三维本构模型基本参数、截面削弱比临界值及其常见摩擦面的抗滑移系数；将各试验结果与高强钢三维本构模型及螺栓抗剪连接承压强度数值分析模型进行对比验证，采用验证后的本构模型与螺栓连接试件数值模型进行系统地参数分析，研究并归纳钢材强度等级、连接构造尺寸（孔径、边距、端距、间距）、剪切面数和螺栓预拉力对高强钢螺栓连接受剪破坏类型与孔壁承压强度的影响；建立高强钢螺栓连接受剪孔壁承压控制承载力的计算方法，提出高强钢螺栓连接构造要求。

限于针对高强钢构件螺栓连接受剪性能理论与试验的已有研究成果较少，无法形成系统的设计理论支持高强钢构件的连接设计。本项目进行了Q550、Q690和Q890高强钢的材料力学性能拉伸与压缩试验、圆棒切口试件拉伸试验、施预紧力单螺栓连接试验、带削弱构件拉伸试验、承压型单、双、多螺栓连接受剪试验和摩擦面抗滑移系数试验；确定了Q550、Q690和Q890高强钢的三维本构模型基本参数、截面削弱比临界值及其常见摩擦面的抗滑移系数；通过将试验结果与螺栓抗剪连接承压强度数值分析结果进行对比验证了数值模型，采用验证后的本构模型与螺栓连接试件数值模型进行了系统地参数分析，归纳了钢材强度等级、连接构造尺寸（孔径、边距、端距、间距）、剪切面数和螺栓预拉力对高强钢螺栓连接受剪破坏类型与孔壁承压强度的影响；最终建立了基于高强钢抗拉强度的净截面强度计算方法与高强钢螺栓连接受剪孔壁承压控制承载力的计算方法，提出了高强钢螺栓连接构造要求。