集成材指接节点抗弯性能试验研究与数值模拟

Experimental study and numerical simulation of bending behavior of finger joints for structural glued laminated timber

为研究结构用集成材指接节点在弯矩作用下的破坏机理和损伤演化规律,设计并制作了6个指接节点试件,对其进行单调加载试验。采用有限元软件ABAQUS建立指接节点精细化有限元分析模型。通过粘聚区模型跟踪指接节点区域的损伤演化过程。试验结果表明,指接节点的主要破坏模式以胶层受拉和受剪破坏为主,木材顺纹受拉破坏相对有限。有限元模型对指接节点的初始刚度和极限承载力具有良好的预测精度,满足工程精度要求。参数分析结果表明,木材顺纹抗压弹性模量对指接节点的初始刚度具有显著影响;横纹抗压弹性模量对指接节点的初始刚度的影响并不显著。胶层抗拉强度和抗剪强度对指接节点极限承载力均具有显著影响。

To investigate the failure mechanism and damage evolution of finger joints for structural glued laminated timber under pure bending,six finger joint specimens were carefully designed and tested under monotonic loading.A finite element method based model was developed on the basis of ABAQUS software.Cohesive zone model was adopted to trace the damage evolution of finger joints.The test results indicate that the main failure modes of finger joints are fracture and shear failure of glue.Fracture failure in longitudinal direction take place in the partial timber of the finger joints.The finite element model has good prediction accuracy for the initial stiffness and ultimate bearing capacity of finger joints,which can satisfy the engineering accuracy.Parametric study implies that the longitudinal compression elastic modulus of timber has significant influence on the initial stiffness of finger joint,while the influence of radial and tangential compression elastic modulus on the initial stiffness of finger joint is not significant.Both the tension and shear strengths of glue play an important role in the ultimate capacity of finger joint.