摘要
针对导管架海洋平台中管节点结构加固的数值模拟,考虑到单一尺度的导管架平台有限元模型难以反映结构局部细节特征的局限性,建立了导管架平台的多尺度数值模拟方法,并开展了多尺度模拟方法在管节点加固中的应用研究。基于多点约束(MPC)的跨尺度关联方法建立了体-管多尺度模型,并对其网格密度进行了验证;通过与精细模型及宏观模型的结果进行对比,分析了多尺度模型的计算精度。在管节点精细有限元模型的基础上,建立了肋板加固的模型并进行了参数的优化分析,进而对加固效果进行了分析。结果表明,基于多尺度方法建立的导管架模型可以兼顾管节点局部的计算精度和整体计算的效率,且肋板加固可有效改善管节点局部的应力集中效应。
The present paper is aimed at establishing a multiscale model based on the multipoint constraints( MPC) method for the numerical simulation of the tubular joints reinforcement in the jacket platform,considering the limitation that it would be difficult for the single-scale finite element model to simulate the local details of the jacket platform structure. To achieve the said purpose,first,MPC method is used to deal with the connection between the pipe elements and the solid elements,and we established a solid-pipe multiscale model with its grid density being verified. We have also made a results comparison under the different grid densities to determine the optimum grid density,taking into account the calculation accuracy and efficiency,we have chosen an appropriate grid generation method. Then,comparing with the results of the micro-scale and the macro-scale models,we have made an analysis of the accuracy of the multi-scale model,in which 3 different loading conditions are simplified as follows: the pressure load,the shear load and the pressure-shear composite load to be applied to the end of the pipe. Responses of the micro-scale model and the multi-scale model under the different loading conditions are obtained,with 24 nodes selected for comparison between the 2 models. Those nodes are chosen from the circumferential direction and the altitude direction,respectively. The results of our comparison show that,under the 3 different loading conditions,the differences between the multi-scale model and the micro-scale model ought to be concentrated at the interface of different element types. Further comparisons have been made from the height direction along the circumferential direction with maximum differences. And,it can be concluded that the differences should be gradually turning to zero with a certain distance getting away from the interface,which proves that the stress can be transferred accurately between different models and the MPC method ought to be correct. What is more,we have also succeeded in reducing the calculation time of multi-scale model by 39%,which can be taken as a great improvement of the calculation efficiency. Last,based on the finite element model of the tubular joints,we have established the model of the ribbed plate reinforcement with the parameters optimized for choosing the appropriate length and thickness of the ribs. What the results show are that the reinforcement has little effect on the deformation of the tubular joints,but the stress concentration has been reduced noticeably,which indeed helps to improve the bearing capacity of tubular joints. All the above findings suggest that the multi-scale model can satisfy both the calculation accuracy of the tubular joint and the efficiency of the overall jacket structure,whereas the ribbed plate reinforcement can effectively reduce the local stress concentration effect of the tube joints.
作者
林红
齐宝
杨蕾
马明骏
陈国明
LIN Hong;QI Bao;YANG Lei;MA Ming-jun;CHEN Guo-ming(Center for Offshore Engineering and Safety Technology,China University of Petroleum,Qingdao 266580,Shandong,China;College of Pipeline and Civil Engineering,China University of Petroleum,Qingdao 266580,Shandong,China;College of Science,China University of Petroleum,Qingdao 266580,Shandong,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2019年第5期1618-1625,共8页
Journal of Safety and Environment
基金
国家重点研发计划项目(2017YFC0804501)
国家自然科学基金项目(51879272,51579246)
中央高校基本科研业务费专项(18CX02074A)
关键词
安全工程
导管架平台
多尺度模拟
肋板加固
多点约束方法
safety engineering
offshore jacket platform
multiscale simulation
rib reinforcement
multi-point constraint method
