考虑复杂预应力的深海立管参激稳定性

Parametric Stability for Deep-Sea Marine Riser Under Consideration of Complex Pre-Stress Force Distribution

针对立管结构中存在着复杂预应力分布的问题,探讨了立管受海洋平台升沉运动所引起的立管参激振动问题.基于结构预应力和立管振动理论,开展了含复杂预应力的顶张力立管结构参激振动问题研究.对顶张力立管的参激振动进行了数值计算,对比了复杂预应力大小、方向对立管结构固有频率、振型及参激不稳定区的影响.计算结果表明,焊接残余应力的存在使立管振动频率、振型、不稳定区大小和迁移方向发生改变,影响着立管结构的共振特性.

In present research,the parametric vibration problem of marine riser structure which is subjected to the heave of floating platform with complex pre-stress force distribution is proposed.According to the structure pre-stress theory and riser structural vibration theory,the parametric vibration problem of toptensioned riser(TTR)structure with complex pre-stress distribution is discussed.At the end,by taking the parametric vibration of TTR as an example,the influence of the amplitude value and direction of complex pre-stress on natural frequency,mode shape and instability domains are compared by using numerical analysis.The result shows that the existing of welding residual stress gives an obvious influence on natural frequency,modal shape,size of instability domains and migration direction of the riser structure,and the resonance characteristics may be altered.