输电塔螺栓搭接滑移过程的数值模拟

FINITE ELEMENT SIMULATION OF BOLT SLIPPAGE IN THE LAP JOINTS OF TRANSMISSION TOWER

螺孔直径一般都大于螺栓外径,因此当横向载荷超过一定数值时,螺栓连接件之间将发生相对滑动,这一过程就是螺栓滑移.在输电塔的结构分析中一般不考虑复杂的螺栓滑移,以致在煤矿采空区或冻胀区等可能导致输电塔塔基非均匀沉降的地区中,传统结构分析软件未能很好地判断出输电塔的运行状态,因此对螺栓滑移过程的准确分析是十分重要的.本研究通过有限元方法,建立输电塔角钢螺栓搭接结构的三维有限元模型,对已有的单螺栓滑移试验进行数值模拟,首次通过数值模拟成功还原已有试验的结果,并进行了搭接结构的滑移试验和模拟验证.通过数值模拟及与已有试验结果的对比,分析了影响滑移曲线的因素,并初步给出各模拟参数的取值范围.

The diameter of bolt hole is usually greater than the outer diameter of bolt.Therefore,members of bolted-joint will slip relatively when the transverse load reaches a certain level.The slip process is called bolt slippage and it has not been considered in the present structure analysis of lattice transmission towers.For this reason,conventional structural analysis software could not predict the structural capacity of lattice transmission towers on moveable foundations.Therefore,it is significant to make a precise analysis of joint slippage.In this research,a three dimensional finite element model of bolted-joint was established.Simulation results met well with the experimental ones for the first time,and a new slip test of lap joint was conducted.By comparing the simulation and experimental results,the influencing factors on bolt slippage were analyzed,and the values of simulation parameters were suggested.