拱形张弦胶合木梁结构受力性能试验研究

发布时间：2018-02-04 05:26

本文关键词： 张弦胶合木梁结构拱形木梁预应力静力试验全跨活荷载半跨活荷载承载力受力性能　出处：《建筑结构学报》2014年05期 　论文类型：期刊论文

【摘要】：为研究拱形张弦胶合木梁结构的受力性能和破坏形态,进行了5榀张弦胶合花旗松木梁的张拉试验,活荷载全跨、活荷载半跨布置基本组合加载试验,以及活荷载全跨布置下极限承载力试验,分析试件关键点的位移、应变和拉索内力,观测了试件的破坏模式。结果表明:张拉试验中拱形木梁反拱值主要取决于拱跨比和初始预拉力。全跨活荷载加载试验中,跨中最大挠度达到木梁跨度的1/250~1/330。在张弦木梁的承载力试验中,跨中受拉区发生脆性劈断之前,跨中位移和应变与加载点荷载基本呈线性关系,跨中最大位移达到木梁跨度的1/60~1/70,花旗松的屈服压应变约为0.5%,极限拉应变约为0.45%;木梁在整体破坏时,跨中最大挠度达到木梁跨度的1/41~1/45,极限压应变约为0.9%,表现出一定的塑性性能;提高拱跨比或垂跨比,均能适当提高拱形木梁的承载力;增大木梁截面积对木梁承载力的提高幅度不大。
[Abstract]:In order to study the mechanical behavior and failure pattern of the arch Zhang Xian glued wood beam, the tensile tests of five UNOMI_person1# glued Pinus flagellus beams were carried out. The basic combined loading tests were carried out with full span of live load and half span arrangement of live load. As well as the ultimate bearing capacity test under full span layout of live load, the displacement, strain and cable internal force of the key points of the specimen are analyzed. The failure mode of the specimen is observed. The results show that the reverse arch value of the arch wooden beam is mainly determined by the ratio of arch span to span and the initial pretension force in the tensile test. The maximum deflection in the span reaches 1 / 250 / 330 of the span of the wood beam. In the test of the bearing capacity of the beam string, before the brittle splitting occurs in the tensile zone of the span. The midspan displacement and strain have a linear relationship with the loading point load. The maximum displacement of the span reaches 1 / 601 / 70 of the span of the wood beam, and the yield compressive strain of Pinus flagelliana is about 0.5%. The ultimate tensile strain is about 0.45; During the whole failure, the maximum mid-span deflection reaches 1 / 41 / 45 of the span, and the ultimate compressive strain is about 0.9, showing a certain plastic property. Increasing the ratio of arch span to span or vertical span ratio can improve the bearing capacity of arch beam. The increase of cross section area of wood beam has little effect on the bearing capacity of wood beam.
【作者单位】：东南大学混凝土及预应力混凝土结构教育部重点实验室;上海市工程结构新技术重点实验室;
【基金】：国家自然科学基金项目(51178115) 江苏高校优势学科建设工程资助项目上海市科委青年科技启明星跟踪计划(11QH1202100)
【分类号】：TU366.3
【正文快照】： 0引言从20世纪40年代开始,研究者们通过利用金属材料(钢筋、钢板或铝板等)来增强胶合木梁,并取得了一定成果。Bulleit[1]的研究表明,含水率低的木梁采用钢绞线加固后刚度相对普通木梁提高了24%~32%,受弯承载力提高约30%。Gardner等[2]采用钢筋加固木梁以提高构件的承载力,并减

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