文献类型：期刊文献

中文题名：国产落叶松平行弦轻型木桁架静力承载性能

英文题名：Load-Carrying Capacity of Larix kaempferi Light Wood Trusses

作者：王滋[1] 周贤武[1] 武国芳[1] 钟永[1] 任海青[1] 赵荣军[1,2]

第一作者：王滋

通信作者：Zhao, Rongjun

机构：[1]中国林业科学研究院木材工业研究所;[2]中国林业科学研究院林业新技术研究所

年份：2018

卷号：54

期号：2

起止页码：137-144

中文期刊名：林业科学

外文期刊名：Scientia Silvae Sinicae

收录：CSTPCD;;EI(收录号：20182305288893);Scopus(收录号：2-s2.0-85048026933);北大核心:【北大核心2017】；CSCD:【CSCD2017_2018】；

基金："十二五"国家支撑计划课题"结构用木质复合材料构件制造技术研究"(2015BAD14B0502)

语种：中文

中文关键词：国产落叶松;国产齿板;轻型木桁架;有限元模拟;承载性能

外文关键词：domestic larch（Larix kaempferi）;domestic truss plate;light wood truss;finite element simulation;load-carrying capacity

分类号：TU366.2

摘要：【目的】研究国产落叶松轻型木桁架的静力承载性能,为轻型木结构建筑的本土化发展提供科学依据。【方法】以国产日本落叶松和国产齿板为试验材料,设计制作2种工况共6榀跨度为4.8 m的平行弦轻型木桁架。通过静力承载试验,研究轻型木桁架的极限荷载、受力分布和破坏形式,并通过建立有限元模型与试验结果进行对比分析。【结果】P和L型轻型木桁架的极限荷载平均值分别为22.45和22.94 k N,是设计荷载的2.27和2.32倍,变异系数分别为7.9%和7.1%。P型轻型木桁架最终破坏为脆性破坏,主要破坏点为桁架三分点处(即集中荷载施加处)和两端斜腹杆连接节点;L型轻型木桁架在2倍设计荷载之后逐渐出现平面外变形,当侧向变形较大时失去承载能力。通过SAP 2000有限元模拟发现,节点挠度与试验结果基本相符,挠度最大值为跨中位置,并向两端逐渐减小;弯矩最大值和轴力最大值在桁架弦杆的三分点处和两端斜腹杆节点,与试验结果相符。【结论】2种轻型木桁架在设计荷载下承载性能均较好,但由于木材非均质特性及加工差异表现出一定的离散程度;较P型轻型木桁架而言,L型轻型木桁架承载能力略高,但其面外刚度较小易发生侧向变形,在实际应用中应采取措施减小侧向变形,而P型轻型木桁架面外刚度较大相对稳定,更利于实际应用;分析认为平行弦轻型木桁架的薄弱环节在端部节点和集中荷载施加处,SAP 2000有限元模拟可以有效预测轻型木桁架在实际应用中的受力和变形情况。
【Objective】 The load-carrying capacity of light wood trusses made with domestic Larix kaempferi was investigated in this study,which provided a scientific basis for the development of light framing wood construction in China.【Method】 Six parallel chord trusses were fabricated with Larix kaempferi and domestic truss plates in two types.The ultimate load,stress distribution and failure mode of light wood trusses were studied by static load test,then the results were compared with that of finite element model.【Result】 The results indicated that the ultimate loads of P and L type light wood trusses were 22. 45 k N and 22. 94 k N,respectively,which were 2. 27 and 2. 32 times as large as the design load. The variation coefficients of P and L light wood trusses were 7. 9% and 7. 1%. The failure mode of P type light wood truss was brittle failure,and the failure mainly occurred at the trisection points of truss where concentrated load applied and two ends where the diagonal member connected with the top chord. Out plane deformation always observed in the L type light wood truss when the load reached about twice of the design load,and it reached its load-carrying capacity when the lateral deformation was large enough. Through the SAP 2000 finite element simulation,it could be found that the joint deflection was almost consistent with the experimental results. The maximum deflection was in the mid-span and decreased gradually to both ends. The maximum bending moment and the maximum axial force were obtained at the trisection points of the truss and the ends joints connected with diagonal member, which was coincided with the experimental results.【Conclusion】 Both of the two kinds of light wood trusses possess good load-carrying capacity under design load,but they show a certain degree of dispersion due to the wood heterogeneity and the processing types. The bearing capacity of L type light wood truss is higher than that of P type light wood truss,but it is more prone to lateral deformation for the out of plane,which stiffness is small and need to be strengthened in application. The P type light woodtruss is more stable to practical application. Moreover,the weakest point of the parallel chord light wood truss exists at the end joint and the joint where concentrated load applied,which is consistent with the test results. SAP 2000 can be used to predict the stress and deformation of light wood truss in practical application.