空仓工况下群仓中各单仓动力相互作用分析

为研究群仓中各单仓之间的动力相互作用,以上海外高桥某储存粮食用群仓为背景,制作了2行3列共6个单仓组成的群仓模型,群仓模型具有钢板顶盖以模拟实际中的仓上建筑物,具有刚性底座以模拟实际中的基础结构。通过对空仓工况下的群仓模型进行有限元数值分析,得到了其各阶模态,对模型前五阶模态振型进行分析,结果表明,群仓模型前两阶模态振型为6个单仓一起沿群仓整体对称轴的弯曲变形,单仓之间动力相互作用可以忽略,而且前两阶模态振型相互正交。群仓模型第三阶模态振型为6个单仓绕群仓整体平面中心的扭转变形,同时伴随有4个角仓的弯曲变形,由于中间仓受约束程度强,其动力反应微弱;群仓模型第四阶、第五阶模态振型主要体现为4个角仓的局部变形,而不再是6个单仓的整体变形,单仓因所处位置不同受约束程度不同,动力反应大小不同;群仓模型的第三阶及以上模态振型体现了单仓之间的不同约束程度及动力相互作用。

Dynamic Interaction Analysis of the Individuals Belong to Empty Group Silos

In order to study dynamic analysis of the individuals belong to empty group silos,a group silos model was made based on a granary in Shanghai Waigaoqiao. It has 6 silos with 2 rows and 3 columns. A steel plate was designed for simu-lating buildings on top of the group silos, and a rigid base was designed for simulating its foundation. Then FEM was used to obtain its modes,and the first five mode shapes were analyzed. The results showed that the 6 individuals bend along the axis of the group silos together with each other in the first two orthogonal modes,therefore,the dynamic interactions are ig-nored. For the third mode, it is mainly the torsional deformation of the 6 individuals around the plane centre of the group silos,simultaneously, the four silos in the corner bend,but the dynamic response of the middle silos is weak due to the con-straint of the other silos. For the fourth and the fifth modes,it is mainly local deformations of the four silos in the corner,but not the overall deformation. What's more,the dynamic response is different for the 6 silos due to their positions. Then it fol-lows that the different constraints and dynamic interactions among the 6 silos are reflected by the third mode and above.