Analitical Model of Seismic Behavior of Wooden Houses

1.剪力墙及钉节点的低周反复荷载试验研究为了建立木结构房屋抗震性能的模型数据库，对木结构剪力墙及钉节点进行了低周反复荷载试验。对带9.5mm外护层的S-P-F二×四框组合剪力墙进行了单调和低周反复荷载试验。胶合板、定向刨花板和12.5mm石膏板的试验结果表明：(1)在反复荷载作用下，钉缝和剪力墙的极限承载力与单调加载试验相比分别下降20 ~ 40%和20%左右。(2)由钉缝计算得到的剪力墙屈服强度和极限承载力与试验结果吻合较好。(3)剪力墙和钉缝的等效粘滞阻尼率约为15%，与位移无关.地震反应分析的建模根据试验结果建立了钉合结构的荷载-位移关系模型。背载曲线由边界位移内和边界位移外的不同函数模拟，其中位移大于边界位移的相反方向导致强度退化。该模型对荷载-位移关系的模拟结果与试验结果吻合较好。利用该模型模拟了木框架剪力墙的荷载-位移关系。模拟结果与试验结果吻合较好，表明该模型适用于木框架结构的地震反应分析。

1. Reversed cyclic loading tests on Shear walls and nailed jointsWood-farmed shear walls and nailed joints sheathed with various sheet materials were subjected to reversed cyclic lateral loading to obtain the database for modeling the seismic behavior of wood-framed buildings. Monotonic and reversed cyclic, loading tests were conducted on the shear walls composed of S-P-F two-by-four framing sheathed with 9.5mm. plywood, OSB and 12.5mm gypsum board with GN 50 and GN40, and the followings were concluded. (1) Ultimate strength of nailed joints and shear walls subjected to reversed cyclic loading decreased 20 to 40% and around 20% respectively in nailed joints and shear walls comparing to those in monotonic loading test. (2) Yield and ultimate strength of shear walls obtained from those of nailed joints showed good agreement with experimental results. (3) Equivalent viscous damping rate of shear walls and nailed joints was approximately 15% regardless of displacements.2. Modeling of earthquake response analysisLoad-displacement relationships of nailed joints were modeled from the experimental results. The back-borne curves were, modeled by the different functions within and beyond a boundary displacement in which the displacement larger than the boundary displacement in the opposite direction caused the degradation of strength. The simulation of load-displacement relationship by this model showed good agreement with the experimental results. Load-displacement relationships of wood-framed shear walls were also simulated by using this model. The simulation showed good agreement with the experimental results, and it was proved that this model is applicable to earthquake response analysis of wood-framed structures.