应县木塔柱架节点力学性能研究

发布时间：2018-08-30 17:09

【摘要】：应县木塔全称佛宫寺释迦塔,始建于公元1056年,现高65.86m,是我国现存最古老最高的阁楼式木结构建筑。木塔历经近千年沧桑,经受了多次强烈地震和战火洗礼,仍屹立不倒,展示着中国古代建筑的高超技术。但由于木材材质变化和强外力的多次作用,木塔现状残损严重,亟待保护与加固。其中,明层柱架节点对于应县木塔整体结构的抗侧力性能十分关键。本文总结了已有的应县木塔木材材性试验,其中古木与新木相比横纹承压强度退化严重,木塔主要用材华北落叶松与东北落叶松力学性能相近。基于现场调查对明层柱架节点进行了进一步构造分析,其中角柱柱头节点中的阑额不做榫头直接插入柱子卯口。以构造相对简单明确的平柱柱头节点为原型,采用落叶松制作了2个足尺模型,在200kN、350kN和500kN轴向压力下,分别进行了顺阑额方向和垂直阑额方向的水平低周往复加载试验,并基于ANSYS对试验进行了数值模拟。试验表明,节点在往复荷载作用下的受力机理为柱子发生摇摆,通过竖向荷载提供的反弯矩抵抗侧力,阑额、普拍枋局部横纹承压,产生较大的塑性变形。柱架节点的主要破坏模式为柱子横纹开裂及普拍枋严重压缩劈裂。节点整体抗震性能好,耗能能力强,但自恢复能力差,受荷后残余变形大。在往复荷载作用下,会出现明显的残损现象。节点在各方向上力学性能不同,顺阑额方向相比垂直阑额方向,节点刚度大,承载力高,延性和耗能性能差,但总耗能能力(总滞回面积)强。竖向荷载大小对节点力学性能也有影响,随竖向荷载的增加,节点的刚度增大,但耗能性能基本不变。
[Abstract]:Yingxian wooden tower, which was built in 1056 AD and is now 65.86m high, is the oldest and highest attic wooden structure in China. After nearly a thousand years of vicissitudes, many strong earthquakes and baptism of war, the wooden tower still stands, showing the superb technology of ancient Chinese architecture. However, due to the change of wood material and the effect of strong external force, the status quo of wooden tower is badly damaged, which needs to be protected and strengthened urgently. Among them, the open layer column frame joint is very important to the lateral force resistance of the whole structure of Yingxian wooden tower. In this paper, the existing timber properties tests of Yingxian wooden tower are summarized. The compressive strength of the old wood is more serious than that of the new wood, and the mechanical properties of the main timber of the tower are similar to those of the northeast larch and the North China larch. Based on the field investigation, the structure of the open layer column joint is further analyzed, in which the diaphragm in the corner column joint is not tenon directly inserted into the post socket. In this paper, two full-scale models are made by using larch as a prototype with relatively simple and definite structure. Under the axial pressure of 200kN 350kN and 500kN, the horizontal low-cycle reciprocating loading tests are carried out in the direction of the diaphragm and the direction of the vertical diaphragm, respectively. The experiment is simulated based on ANSYS. The experimental results show that the stress mechanism of the joint under reciprocating load is that the column is swayed and the anti-bending moment provided by vertical load is used to resist the lateral force, the diaphragm and the common pat Fang local transverse line pressure, resulting in large plastic deformation. The main failure modes of column joints are column transverse cracking and severe compression splitting. The whole joint has good seismic performance and strong energy dissipation ability, but its self-recovery ability is poor, and the residual deformation after loading is large. Under the action of reciprocating load, there will be obvious damage phenomenon. The mechanical properties of the joints are different in each direction. Compared with the vertical apertures along the apertured direction, the joints have large stiffness, high bearing capacity, poor ductility and energy dissipation, but the total energy dissipation capacity (total hysteresis area) is strong. With the increase of vertical load, the stiffness of the joint increases, but the energy dissipation performance is basically unchanged.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU366.2

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