轻木钉节点恢复力模型研究及参数识别

Parameter Identification and Research on Restoring Force Model of Nail Joints in Light Wood Structure

以低周反复作用下轻型木结构钉连接节点的试验为依据,提出了一种7个参数的钉节点恢复力模型,考虑正负方向不同的捏缩点和滑移效应,采用贝叶斯方法识别模型参数.结果表明,贝叶斯参数识别的精度依赖于所采用的数据,识别得到的恢复力模型最有可能值和协方差矩阵可用于相同条件下钉节点的计算.利用识别的结果对其反应进行模拟,所得计算结果与试验值符合良好.文中提出的恢复力模型为钉节点分析提供了可参考的力学模型,将贝叶斯理论扩展应用到恢复力模型参数识别中,为轻型木结构非线性滞回分析的研究提供了一种新的方法.

This paper proposed a novel mechanical model of nail joint restoring force with seven model parameters were based on low cycle and repeated tests of light wood structure nail joints. This model considers different pinch points and slip effect in both positive and negative directions. Model parameters were identified by using the Bayesian method.The results show that the accuracy of Bayesian identification method relies on the quality of raw data. The result of the most probable value and the associated covariance matrix can be determined and used to the calculation of nail joint with the same conditions. The model response obtained from the result of parameters identification is in good agreement with the experimental results. The restoring force model proposed in this paper provides a reference for future nail joints analysis. Furthermore,Bayesian method is extended to parameter identification of nail joints restoring force,providing a novel way to investigate nonlinear hysteretic analysis of light wood structures.