Dynamic Characteristics and Failure Mechanisms of Spacial Structures

根据球壳在竖向地震作用下的大地震反应的数值结果，从不同的角度指出了在设计时考虑空间结构动力处理的重要性。本文的目的是通过对单层网壳结构进行自由振动试验和振动台试验来研究网壳结构的动力性能。该模型为三角形单元单层网壳结构，由61个节点连接，底板直径为2.8m，高程为37.5 cm，矢跨比为0.134。主要研究了(1)自由振动试验、(2)上下运动振动台试验、以及(3)与相似模型和数值分析结果的比较。

The importance of considering the dynamic treatments of spacial structures at the time of design has been pointed out from the various points of view, based on, for example, the numerical results of large seismic responses for a spherical shell due to vertical earthquake motions.The purpose of the present study is to investigate the dynamic behaviours of reticulated single-layer shallow domes by means of the free vibration tests and the shaking table tests by a newly developed model using "spring" for each member. The results are compared with the another model with the similar configuration and dimension.The model, which is a reticulated single-layer shallow dome with triangular unit, is composed of 132 members connecting at 61 joints, and the base dismeter (a) of this model is 2.8 m. The rise (h) and the rise-to-span ratio (h/a) are 37.5 cm and 0.134, respectively. The stiffness of the member depends on the axial stiffness of the spring, and the members are pin-connected at their joints.The following items are mainly studied:(1) Free vibration tests,(2) Shaking table tests for up-down motion, and(3) Comparison of the results with similar model and numerical analyses.