节点文献
导管架水下调平夹持系统力学分析与实验研究
Mechanical Analysis on Underwater Leveling-gripping System of Jacket and Experimental Research
【作者】 姜沛然;
【导师】 房晓明;
【作者基本信息】 哈尔滨工程大学 , 机械电子工程, 2012, 博士
【摘要】 导管架平台主要由导管架、钢管桩和平台上部结构组成。导管架作为平台的基础,在安装过程中必须要进行调平,其水平精度直接影响到平台的安全性、适应性、使用寿命等各种性能。较深水导管架调平安装过程包括调平阶段和夹持阶段,需要专用调平夹持系统。本文根据中海油综合科研项目“深水导管架安装液压装具研发”的要求,对导管架调平系统进行了分析和研究,设计了适用于国内配套生产的导管架夹持设备和调平系统的实验样机,解决了目前一些调平夹持系统存在的问题,主要包括以下几方面内容。对包括调平器和夹桩器两部分液压装具的机械系统结构进行了详细设计,确定了调平夹持系统工作过程,建立了调平器和夹桩器的三维模型;根据设计结构,分别对调平器及夹桩器的关键部位进行了力学分析,通过分析验证了设计的导管架调平夹持系统机械结构能够满足调平性能要求;对于调平器和夹桩器的夹持机构,依据薄壳弹塑性、稳定性理论分析了被夹持钢管桩和套管在调平过程所需的极限夹紧力载荷。建立了分析夹紧力、夹爪齿嵌入深度与系统承载能力的数学模型,对夹紧力与夹爪嵌入深度非线性关系问题上利用LS-DYNA软件进行显示动力分析,经过分析得出了夹紧力与嵌入深度在塑性变形阶段近似呈线性分布的关系,进而得出夹紧液压缸压力与系统承载能力间的关系;利用有限元方法对夹爪齿部受力进行强度分析,通过分析为确定夹爪结构和材料提供依据;对调平夹持系统中关键部位进行强度分析,对于明显存在材料浪费的套筒进行了拓扑优化;根据对夹爪夹持性能的分析及系统承载的要求,研制了夹爪用新型合金钢,确定了材料的化学成分,对实验用夹爪材料进行了微观组织分析,分别研究了不同退火温度和保温时间对合金钢性能的影响,确定了最佳退火工艺和淬回火工艺。以南海某平台为分析对象,并且根据所处海域的海况,研究了基于莫里森公式和Stokes5阶波理论的波浪载荷对导管架结构的影响;为了得到调平夹持系统在时域内的的动力响应,根据单参数的P-M谱,依据Shinozuka理论,对波浪载荷进行了时域分析;将海流和风载荷按定载荷处理,研究了海流以及风载荷对导管架结构的影响;确定了不同重现周期下的极端海况,从而确定了调平过程中导管架承受的主要环境载荷及其组合方式;利用SACS软件,针对南海某平台计算了其在不同重现期极限环境载荷影响下的底部动力响应;利用ADAMS软件对调平夹持系统的调平过程进行动力学分析,确定关键夹持接触部位的动力响应,分析了不同重现期环境载荷对调平夹持系统的影响,提出了极端恶劣海况下调平的解决办法。分析了传统调平方式的弊端以及存在的问题,针对这些问题,设计了导管架最优调平控制系统,包括建立系统的几何模型,制订最优调平策略,设计基于Mamdani模糊控制器,建立受控对象的数学模型;利用软件建立调平控制系统仿真模型,分别对无环境载荷和有环境载荷影响下的调平系统调平过程进行仿真,从仿真结果看,控制系统调平效率、精度比传统调平方式明显提高,可以克服环境载荷作用下产生的随机扰动,鲁棒性好。实验部分,确定了夹爪铸造工艺方案,制备夹爪样件,对夹爪的材料进行实验研究,并通过实验确定其强度;设计并研制了嵌入式楔形增力夹持机构实验样机,通过相关实验结果及与理论分析的比较,验证了调平器夹持机构的重力自锁功能以及理论分析的正确;设计并研制了夹桩器的实验样机,对夹桩器的油源供油及液压缸保压性能进行了实验验证;为了验证夹桩器的夹持性能,在某港口对夹桩器进行了模拟实际工况条件下的夹持性能实验,实验监测结果证明夹桩器可满足实际夹持要求;对钢管桩表面压痕深度及夹爪齿的断裂形式进行了分析,分析结果为改进夹爪齿形结构,提高调平夹持系统夹持性能指出了进一步优化的方向,为调平夹持系统的实际应用提供了宝贵依据。
【Abstract】 Jacket platform mainly consists of jacket, steel pipe pile and the upper part. Jacket as aplatform base must be leveling in the installation process, the level of accuracy directly affectsthe platform safety, adaptability, service life and other properties. In deeper water jacketleveling process including the levelling stage and clamping stage, the specialleveling-gripping system is required. According to " The hydraulic equipment of deep waterjacket installation research and development " which the comprehensive scientific researchproject of CNOOC requirement, in this paper, the jacket leveling system is analyzed andstudied, jacket clamping device and leveling system prototype which applicable to domesticproduction is designed, solve the current problems of leveling-gripping system. It mainlyincludes the following aspects.Mechanical system structure including skirt pile gripper and jacket leveling equipment isdesigned, the leveling-gripping system work process is determined, the three-dimensionalmodel is established. According to the designed structure, the key parts mechanical propertiesof skirt pile gripper and jacket leveling equipment is analyzied, through the analysis to verifythe design of jacket leveling-gripping system mechanical structure can meet the levelingperformance requirements. On the basis of shell elastoplastic, stability theory, the limitclamping force which clamped pipe pile and the casing in the leveling process required isconfirmed.The mathematical model is established, which is used to analyze the clamping force,clamping claw tooth embedded depth and system bearing capacity. The nonlinear relationshipbetween clamping force and gripper embedding depth is analyzied by the LS-DYNA softwareto display dynamic analysis, the result shows that clamping force and embedding depth in thestage of plastic deformation have a linear relationship, and draw a relationship betweenclamping hydraulic cylinder pressure and the bearing capacity of leveling-gripping system.Finite element method is used to analyz clamp claw tooth stress intensity, through the analysisto determine the clamping claw structure and material. The leveling-gripping system key partsusing ANSYS to check the strength, the sleeves which have apparent material waste areoptimized. According to the requirements, a new type of alloy steel is developed, the chemicalcomposition of the materials is designed, the experimental gripper material microstructure is analyzed, the properties of alloy steel is studied in different annealing temperature andholding time, the optimal annealing and quenching tempering explosive art is determined.This paper select a platform locate in South China Sea for leveling object, and accordingto the waters of the sea, the effect of wave load on offshore structure is studied based on theMorrison formula and the Stokes5order wave theory. In order to get a leveling-grippingsystem dynamic response in the time domain, according to the parameters of the P-Mspectrum, based on the Shinozuka theory, the effect of wave load in the time domain isanalyzed. The effect of ocean current and wind load on the jacket structure is studied asconstant load. The extreme sea state under different return period is determined, the mainenvironmental load and its combination which jacket withstand in leveling proces is defined.With SACS software, according to the South China Sea, a platform bottom dynamic responseis calculated under limit environmental load in different return period. Use ADAMS softwareto the leveling-gripping system for dynamic analysis in leveling process, the key clampingcontact site dynamic response is determined, the leveling-gripping system can bear thegreatest environmental load is determine,and presents a extreme weather leveling solution.The drawbacks and problems of traditional leveling method is analyzed, aiming at theseproblems, leveling device hydraulic system and jacket leveling control system are designed,include the establishment of leveling-gripping system geometric model, making optimalleveling strategy, designing fuzzy controller based on Mamdani, establishing themathematical model of controlled object. Using software to establish the leveling controlsystem simulation model, leveling-gripping system leveling process simulation is simulatedwithout the environmental load influence and under the environmental load respectively, fromthe result of the simulation, we know leveling control system efficiency, precision isobviously improves compare with the traditional leveling method, can overcome the effect ofenvironmental load, has strong robustness.In the experimental part, this paper determines the leveling-gripping system claw castingprocess, prepare the sample for claw, make claw material for experimental research, andthrough the experiment to determine its strength. The embedded wedge booster clampingmechanism experimental prototype is designed and developed, the relevant experimentalresults compare with theoretical analysis, which varify the gravity self-locking function ofleveling device clamping mechanism and the theoretical analysis is correct. The pile gripper prototype is designed and developed, oil source and the hydraulic cylinder experiment iscarried out to verify the pressure maintaining performance of pile gripper. The grippingperformance experiment under the actual working conditions is carry out in a harbor, theexperimental monitoring results show that pile gripper can meet the practical steel pipe pileclamping requirements. The depth in surface and the clamping claw tooth fracture forms isanalyzed, the analysis results points further optimizing direction for the improvement of theclamping claw tooth structure and improve the leveling-gripping system grippingperformance, and can provides the valuable basis for leveling-gripping system practicalapplication.
【Key words】 Leveling-gripping system; Environment load; Dynamic analysis; Optimal control; Experimental prototype;