胶合木梁柱嵌入钢板-螺栓拼接节点纯弯与弯剪性能试验研究

Experimental study on bolted glued laminated timber connections with slotted-in steel plates under pure bending and combined shear and bending

为研究胶合木梁柱嵌入钢板-螺栓拼接节点在纯弯和弯剪复合荷载作用下的破坏机理、受弯承载力的变化规律和计算方法,设计并制作了3组共15个足尺节点试件,对其进行单调加载试验。以单螺栓节点横纹承载力计算方法为基础,经推导建立了考虑节点剪弯比影响的节点受弯承载力计算方法。试验和计算结果表明:弯剪复合荷载作用下节点的主要破坏模式为木材横纹劈裂破坏;剪力导致弯矩-转角曲线非线性特征更为明显;节点受弯承载力和延性随节点剪弯比的增大而减小;节点的剪弯比变化使节点受弯承载力和延性下降最多分别达到31.7%和15.6%。此外,对已有的节点受弯承载力计算方法分析可知:基于van der Put模型的节点受弯承载力计算方法具有较高的精度(与试验值偏差在16%以内);而基于Jensen模型和按欧洲规范EN 1995-1-1预测的结果则偏于保守。

To investigate the rotational behavior of bolted glulam connections with slotted-in steel plates under pure bending and combined shear and bending,and establish the moment resistance calculation model,three groups of such connections（ 15 full-scale replicates in total） were tested under monotonic loading. The calculation model for the moment resistance of connection was based on the resistance of single bolted connection loaded perpendicular-to-woodgrain. The results indicate that all connections fail due to perpendicular to wood grain splitting; the presence of the shear force leads to more significant nonlinearity of the moment versus rotational angle curves; the moment resistance and ductility ratio decrease with the increase of the ratio of shear to moment; the maximum decreases of the moment resistance of connection and ductility ratio,respectively,are 31. 7% and 15. 6 %,under the designed shear and moment ratios. Comparison with the test results indicate that the calculation models developed based on the van der Put model can achieve fair agreement with the test results（ error less than 16%）,while the Jensen model and the model suggested in the European design code EN 1995-1-1 are found to be too conservative.