Theoretical and Experimental Study of Nonlinear Dynamic Behaviors of Spatial Structures

本研究从理论和试验两个角度对空间结构的非线性动力行为进行了研究：(1)浅层结构在上下激振作用下的动力屈曲；(2)运动不确定结构的动力特性。在第(1)项中，利用对几何非线性运动方程进行数值积分得到的时程图，研究了结构形状如矢跨比、阻尼和激励类型对动力屈曲荷载的影响。动力屈曲载荷按Budiansky-Roth准则估计。给出了动力屈曲载荷的频变特性。在第(2)项中，提出了一种基于广义逆理论的超静定刚架动力分析的数值方法。运动超静定框架包括索系结构、膜结构、可折叠结构、空间结构等可移动结构，可归类为“不稳定结构体系”.该方法可以有效地用于分析这些结构的动力行为.通过与试验结果的比较，验证了该方法的有效性.

In the research study, the following two items about nonlinear dynamic behaviors of spatial structures were investigated from the theoretical and experimental view points.(1) Dynamic Buckling of Shallow Structures under the Up-and Down Excitation(2) Dynamic Behaviors of Kinematically IndeterminateIn item (1), the effects of shape of structure such as rise-to-span ratio, damping and type of excitation on the dynamic buckling load are numerically examined by using time histories which are obtained by the numerical integration for the geometrically nonlinear equations of motion. Dynamic buckling loads are estimated by the Budiansky-Roth criterion. Frequency-dependent characteristics of dynamic buckling load is shown.In item (2), a numerical method using the generalized inverse theory for the dynamic analysis of kinematically indeterminate framework was presented. Kinematically indeterminate frame includes cable structures, membrane structures, movable structures such as foldable structures, space structures, etc., and is classified into 'Unstable Structural System." The present method can be effectively applied to analyze the dynamic behaviors of these structures. The validity of the present method is examined by comparing numerical results with the experimental results.