Method establishment for the fracturing/collapsing process simulation of wooden houses under seismic loading

我们的最终目标是建立一种模拟大地震作用下木结构房屋性能的计算方法。通过对传统木结构房屋倒塌过程的研究，成功地进行了定性模拟。虽然该模拟技术要达到可与有限元法相媲美的定量模拟还存在一定的障碍。其中一些障碍已经被克服，例如，通过对不同紧固件连接部分的试验，参数化了柱-梁连接的性能。迫击炮壁的破裂行为也逐渐清晰。在这个研究项目中，我们的主要目标是阐明包括大榫孔的连续柱的行为和性能。实际尺寸的单至四个方向开口柱进行静态和动态弯曲试验。在静力试验中，随截面损失的增加，比杨氏模量和抗弯强度减小。但比杨氏模量的下降速率小于期望值。似乎没有那么大的应力集中，需要考虑断裂力学。在大地震作用下，连续柱承受高速荷载。针对这种情况，我们进行了加载速率为2m /sec的动态弯曲试验。我们预计榫头开口对截面损失的影响在动加载中比在静加载中更为重要。但实验结果却是相反的。动态载荷下的比杨氏模量和抗弯强度均比静态载荷下有所增加。使这些结果反映在仿真参数的确定上是我们今后的课题。

Our final goal is to establish a calculating method for the simulation of the behavior of wooden houses under big earthquake. Qualitative simulation of the collapsing process for the traditional wooden houses was made successfully by the research until now. Though there were some hurdles to make this simulation technique to the quantitative one which was comparable to the finite element method. Some of these hurdles were overcome already for example, the behavior of the column-sill connection was parameterized by the experiments on the connecting part with various fasteners. The fracturing behavior of mortars wall was also becoming clear. In this research project, our main target was to clarify the behavior and the performance of the continuous columns which include large tenon openings. Real size columns with single to four direction(s) opening were subjected to static and dynamic bending tests. In static test, specific Young's modulus and bending strength decreased with the increasing loss of cross sectional area. Though the decreasing rate of specific Young's modulus were less than the expected values. It seemed that there were not so large stress concentration which require the fracture-mechanical consideration. Under the big earthquake, continuous columns receive high speed loading. Corresponding to this situation, we made dynamic bending test with the loading rate of 2 m/sec. We anticipated that the influence of the section loss by tenon openings becomes more important in dynamic loading than in static one. But the experimental results were inverse. Both the specific Young's modulus and the bending strength were increased in dynamic loadings in comparison with the static cases. It is our future subject to make these results reflect on the parameter decision for the simulation.