CFRP加固筒-柱支承式筒仓结构动力特性分析

Dynamic characteristic analysis of columns-cylinder supported RC silo strengthened by CFRP

以都江堰某筒-柱支承式钢筋混凝土圆形筒仓结构震后CFRP加固为背景,研究CFRP加固后的筒-柱支承式混凝土筒仓动力特性。根据结构形式及加固措施建立结构加固前后的动力特性分析模型;对结构加固前及加固后的自振频率和周期进行分析;结合汶川地震八角波拟加速度反应谱,对结构加固前后的频率、周期及振型进行了比较与评价。研究表明:①CFRP加固筒仓薄弱部位后,其前10阶频率及周期与加固前相比无明显变化,即CFRP加固未明显改变筒仓的动力特性;②加固后,其第一周期仍然刚好位于拟加速度反应谱的峰值附近,仍属于刚度较大的短周期结构,受地震的影响较大;③加固后,从第3振型开始出现扭转,即扭转振型提前。

The dynamic characteristic of a columns-cylinder supported RC silo which strengthened by CFRP, is analyzed. Firstly, the structural model used to dynamic characteristic analysis is established according to reinforced measures. Secondly, its natural frequencies and periods for both un-strengthened and strengthened by CFRP are carried out separately. And then, the results are compared with each other based on the PGA of WEN-CHUAN earthquake, and it is assessed. At the last, its vibration mode for both un-strengthened and strengthened by CFRP are given out separately. The results show as follows：（~）According to the first ten natural frequencies and periods of vibration,its dynamic characteristic is not changed clearly after strengthened by CFRP; （~）The first period still is nearby the peak value of the PGA of WEN-CHUAN earthquake, it belongs to the structures of low period and large rigidity also and be subjected to earthquake critically;（~）Its third mode is the torsion mode after strengthened by CFRP, and the torsion mode has been moved up.