大跨空间钢网架结构静力和动力性能实验研究

大跨结构静力与动力性能与结构能否安全服役密切相关。文章对某大跨钢网架结构进行了静载试验,并测试了各级堆载条件下网架竖向振动频率。试验中选择在其中一跨的接近中心处(挠度最大点)进行静载和动载试验。采用吊篮法在网架挠度最大点分别施加10kN和20kN配重,得到了加载处的竖向刚度;振动测试表明,该网架在脉动激励下振动卓越频率不明显,在冲击激励下可以得到较好的自由振动波形,并且卓越频率明显。振动测试数据分析中,考虑了各测点的相位关系,分别得到了无配重、10kN配重和20kN配重下钢网架竖向一阶振动频率,可用于设计阶段采用的分析结果的校核。

Experimental study on the static and dynamic behavior of a long span space truss

The static and dynamic behavior of long span structure is related to its service safety.A long span steel space truss was tested by adding artificial mass,and its vertical vibration frequencies under different amount of mass were measured.Static and dynamic tests were carried out at point with maximum deflection.10kN and 20kN weights at the point was added by suspension basket respectively,vertical stiffness was derived.Vibration measurements show that there are no obvious predominant frequencies under micro-tremor excitation;but good waveform and obvious predominant frequencies are measured if the truss is excited by sudden pulse.Phase lag analysis technique is employed in data process.First frequencies under different mass are obtained,and they can be used to calibrating analysis model used in design stage.