建筑结构学报2025，Vol.46Issue(4)：140-152,13.DOI:10.14006/j.jzjgxb.2024.0357
弯剪段开孔意杨旋切板胶合木梁受剪性能试验研究
Experimental study on shear performance of poplar LVL beams with opening in bending-shear region
摘要
Abstract
To investigate the shear performance of Italian poplar laminated veneer lumber(LVL)beams with opening in the bending-shear region,six standard specimens were designed and tested under four-point bending.The shear failure mechanisms of the LVL beams with opening under various parameters were analyzed.Using the extended finite element method and ABAQUS software,a finite element model of perforated beam with virtual cracks was developed.Parametric analyses were performed considering variations in the diameter-to-height ratio,opening shape,and opening center eccentricity,using the validated model.The results show that the unperforated beam experiences bending failure due to tensile cracking at the mid-span.In contrast,beams with circular opening experience longitudinal shear failure at the ends due to stress concentration around the opening perimeter.The maximum transverse tensile strain around the opening perimeter forms an angle of approximately 45°or 225°relative to the longitudinal axis of beam,consistent with the crack initiation angle.As the diameter-to-height ratio increases to 0.5,both cracking and ultimate load capacities of the beams with circular opening significantly decrease,exhibiting more brittle shear failure.When the diameter-to-height ratio increases from 0.3 to 0.4 and 0.5,the ratio of cracking to ultimate load capacity increases from 0.79 to 0.80 and 0.81,respectively.Using carbon fiber reinforced polymer(CFRP)wrapping around the openings effectively suppresses crack propagation and enhance the structural performance of the perforated beams.For the beam with a diameter-to-height ratio of 0.4,the ultimate load decreases by 17.9％and 5.22％,respectively,for one and two layers of CFRP wrapping,compared to the unperforated beam.When comparing circular-opening beam(diameter-to-height ratio of 0.3)to those with square-opening of the same diameter,the square-opening beam shows a 19.35％and 7.81％reduction in cracking and ultimate load capacity,respectively.Increasing the opening center eccentricity is found to improve both cracking and ultimate load capacities.The prediction formulas for the cracking and ultimate load capacities of LVL beams with opening were proposed.The prediction for cracking load is relatively conservative,and the average error between the predicted and experimental results for the ultimate load is 8％.关键词
开孔LVL梁/CFRP/扩展有限元理论/静力试验/受剪性能Key words
LVL beam with opening/CFRP/extended finite element method/static test/shear performance分类
建筑与水利引用本文复制引用
王安涟,张志文,刘雁,王昌远..弯剪段开孔意杨旋切板胶合木梁受剪性能试验研究[J].建筑结构学报,2025,46(4):140-152,13.基金项目
国家自然科学基金项目(51878590),扬州大学研究生国际学术交流专项基金项目(YZUF2024110). （51878590）
