钢夹板-螺栓连接胶合木梁的疲劳性能模拟方法

Numerical Simulation of the Fatigue Performance of Bolted GLT Beams with Sandwiched Steel-plate

基于试验结果,分别考虑了不同的胶合木材料性质设定、不同材料S-N曲线及应力场折减等因素,对钢-胶合木组合构件进行了疲劳数值模拟,确定了合理的模拟方法:即对此类组合构件的模拟中设定钢材为理想弹塑性材料,胶合木在弹性阶段为正交各向异性材料,塑性阶段为各向同性理想弹塑性材料;胶合木梁纯弯疲劳试验中以截面最大应力拟合的S-N曲线适用于中高低周的疲劳分析,由刚度退化程度得到的S-N曲线仅适用于中高周疲劳分析;对工程木区别于清材的缺陷,模拟中应考虑应力场折减,可采用木结构设计中的强度折减方法。

Based on experimental results,various glulam materials assumptions,different material S-N curves,and stress field reduction factors were considered in this numerical simulation,and determined the rational simulation approach,assuming steel as an ideal elastic-plastic material and glulam as an orthotropic material in the elastic phase and an isotropic ideal elastic-plastic material in the plastic phase.The S-N curve fitted with maximum stress in the cross-section for bending fatigue tests of glulam beam is applicable for fatigue analysis at medium to high and low cycles,while the S-N curve obtained from the degree of stiffness degradation is only suitable for fatigue analysis at medium to high cycles.Considering the distinction between engineering wood and clean wood,stress field reduction should be taken into account in the simulation,and the reduction factor can be determined by the strength reduction method commonly used in wood structural design.