周期特性下网架结构振动特性分析

针对工程结构减隔振需求，基于网架结构的周期特性对其进行减隔振性能分析。通过改变节点质量、杆件截面参数，分析其对网架结构减振性能的影响;再对实际工程网架-悬挂吊车结构进行分析，运用频响函数综合法建立整个系统的振动传递模型，在隔振系统中评价该结构的隔振性能。结果表明，网架结构具有一定抑制振动效果，可通过调节杆件截面刚度来影响结构的带隙特征以实现预期减隔振效果；增加网架节点质量，可以很好地改变结构振动特性，尤其是对高频阶段有较好的抑制作用，但减振效果与截面刚度呈负相关；网架-悬挂吊车结构双层隔振系统具有良好隔振效果。合理运用网架结构的周期特性，对结构进行优化布置，可以有针对性地增强网架结构的减振性能。

Analysis of vibration characteristics of space truss structure under periodic characteristics

To meet needs of the vibration reduction of the engineering structure,the vibration reduction and isolation performance of the space truss structure are analyzed based on its periodic characteristics. By changing the mass of joints and the bar section parameters, their influence on the vibration reduction performance of the space truss structure is investigated. Then the actual engineering space truss - suspension crane structure is examined. First, the vibration transfer model of the whole system is established with the frequency response function synthesis method. Next, the vibration isolation performance of the structure is evaluated in the vibration isolation system. The results show that the space truss structure has a certain vibration suppression effect, and the band gap characteristics of the structure can be changed by adjusting the section stiffness of the member to achieve the expected vibration isolation effect. Increasing the mass of the space truss structure joints can change the vibration characteristics of the structure well, especially showing a good inhibitory effect at the high-frequency stage. However, the damping effect is negatively correlated with the cross-sectional stiffness. In addition, the double-layer vibration isolation system of the space truss-suspension crane structure has a good vibration isolation effect. Therefore, the layout of the structure can be optimized in the design stage by rationally making use of the periodic characteristics of the space truss structure, so as to enhance its vibration damping performance.