开封铁塔静力及动力性能研究

The study on the influence of stress from inclination of the Kaifeng Tower

开封铁塔是国家首批重点文物,价值重大。针对其倾斜导致的结构安全问题,采用理论结合数值模拟的方法研究了铁塔倾斜对塔身应力的影响。通过理论分析,计算了开封铁塔的体积、自重、重心位置,以及在自重、风荷载和地震荷载作用下的内力,并进行了地震作用下的结构倾覆验算、强度验算。然后,应用ANSYS有限元分析程序计算了开封铁塔的自振特性,进行了7度多遇地震时的反应谱和时程抗震分析。研究结果表明,理论分析、反应谱分析及时程分析结果一致,当塔顶偏移位移达1.5 m时,在地震作用下结构最大应力将超过容许应力。

The Kaifeng Tower is very valuable as a national important cultural relic. Aiming at the problem of safety caused by the inclination of the Kaifeng Tower,the study on the influence of its lean to its stress was carried out. The volume,self-weight,location of the centre of gravity and the internal forces under the action of self-weight,wind load and earthquake load were calculated. And the analysis of structural overturn and strength were completed. Then the software ANSYS was used to carry on the analysis of natural vibration characteristics,response spectrum analysis and transient analysis under the 7 degree earthquake. Results show that the results of theoretical analysis,response spectrum analysis and transient analysis are identical. When the max lateral displacement of the Kaifeng Tower top reaches 1. 5 m,the max stress of the tower exceed the allowable stress.