双层压杆支撑结构耗能特性及减振性能研究

Energy Dissipation Characteristics and Vibration Reduction Performance of Bilayered Bracing Structure

摘要: 波浪砰击载荷易引起导管架平台整体和局部结构剧烈振动，导致结构疲劳损伤和设备失效。为使振动快速衰减，设计了一种多稳态钢质撑杆结构，其中内置双层压杆具备高刚度高阻尼特性。循环载荷下，双层压杆激励与响应发生反向，产生滞后阻尼。结合层合结构刚度等效和杆件稳定分析方法，理论计算了双层压杆多稳态跳变阈值，建立了典型结构参数与弯曲中性轴间的联系。而后讨论了承载和耗散特性的几何参数相关性。将新型撑杆引入导管架平台，数值模拟砰击载荷并分析导管架自由振动，耗散撑杆不改变导管架结构刚度的同时大大提高了动能转换效率。导管架振幅衰减系数近8倍于传统导管架结构。

Abstract: The severe overall and local vibration of jacket platform are triggered by wave slamming load, resulting in structural fatigue damage and equipment failure. In order to reduce the vibration rapidly, a multi-stable bracing system was designed, in which the built-in bilayered column presented high stiffness and damping. The excitation and response of bilayered column created reverse under cyclic load, then inducing hysteresis damping. Based on the combination of stiffness equivalence of laminated structure and method of stability analysis, the multi-stable jump threshold was calculated theoretically, and the relation between typical structural parameters and bending neutral axis was established. Subsequently, the effect of geometrical parameters on bearing and dissipation characteristics was discussed. Finally, the slamming load was implemented numerically to jacket platform containing new braces. The results show that the kinetic energy conversion efficiency is greatly improved and the stiffness of jacket platform remains unchanged. The amplitude decay co-efficient is nearly 8 times of the traditional jacket structure.