共查询到19条相似文献，搜索用时 109 毫秒
1.
水下采油树井口连接器是连接采油树和井口的关键设备,对深海水下勘探开发及采油树的安装连接具有不可或缺的重要意义。以一种锁块式水下连接器为例,介绍其结构组成和工作原理,通过有限元建立连接器的三维模型,分析连接器在下放安装工况、连接锁紧工况、正常生产工况和钻完井工况下的连接性能,得出井口与采油树本体接触面作用力、VX钢圈接触应力和锁块受力情况随外部载荷的相互关系。结果表明,VX钢圈在整个过程中都能够保持良好密封,井口与采油树本体接触面未发生分离,弯矩对连接器连接性能影响很大,在额定弯矩作用时连接器部分锁块已发生弹塑性失效。 相似文献
2.
HDPE深水网箱抗风浪流性能的海区验证试验 总被引：5，自引：0，他引：5
对HDPE深水网箱2000～2004年间的抗风浪流性能进行了海区验证试验.通过对HDPE深水网箱扶栏、框架、网具以及固泊系统受损率的统计,根据扶栏、框架、网具以及固泊系统在整个深水网系统中的重要程度,分别给予一定的权重统计出深水网箱的整体受损率,能比较客观地反映深水网箱的抗风浪流性能.海区验证试验结果表明,HDPE深水网箱抗风力达35 m/s、抗浪高6 m、抗流速1.0 m/s,与其设计参数基本相同.同时,为了增加HDPE深水网箱的抗风浪流性能,建议扶手管从110 mm改为125 mm、主浮管从250 mm改为300 mm、扶栏高度从1 m降低为0.8 m或0.6 m.风力主要影响扶栏系统,流速主要影响网具系统,而波浪对HDPE圆形浮式深水网箱的框架、网具、固泊系统以及网箱整体结构均有明显影响. 相似文献
3.
分析了我国深水钻井的现状和未来发展趋势,调研分析了深水钻井所面临的困难和深水钻井液必须具备的基本性能。在理论推导并结合实践的基础上,研制了深水低温钻井液基本性能模拟实验装置、深水钻井液水合物生成与抑制评价实验装置以及深水钻井液循环与井壁稳定模拟实验装置等,并对模拟装置的实验可行性和平行性进行了验证。实验结果表明,新研制模拟实验装置控制精度较高、实验平行性较好,能够满足深水钻井液性能测定与评价的基本要求,为我国深水钻井液技术研究奠定了一定的室内实验研究基础。 相似文献
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近年来,深水半潜平台已成为海洋工程领域研究的热点。分别通过模型试验和数值模拟的方法,对不同水深和浪向条件下作业的深水半潜平台的运动以及系泊系统的受力进行全面分析。在此基础上,进一步研究平台在深水作业时的运动和动力特性,以及水深和环境海况的变化对平台运动和系泊系统受力的影响规律。同时,对比完整系泊系统的情况,对一根系泊缆破断的极端状态下平台的特性开展研究,获得运动和系泊系统受力的变化规律。对比发现试验和数值的结果能较好地相互吻合,且均能满足相应的安全度要求,保证平台实际作业时的可靠性,为深水半潜平台设计中的安全极限计算提供一定的依据。 相似文献
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以两模块平台集成化箱体式连接器为研究对象,研究此类连接器的力学特性,探究箱体式连接器的应力分布状态以及重要力学参数。以弹性接触方程为基础,采用罚函数方法,建立连接器本体、钢轴与轴承座之间的接触关系,结合模型试验,验证所提出接触计算方法准确性,并进一步对连接器半对称结构进行极限强度分析。分析结果表明:连接器的纵向和垂向的极限承载力约为40 000 k N,其纵向弹性刚度约为3×109N/m,垂向弹性刚度约为1.5×109N/m。对连接器应力分布进一步分析表明,连接器主体结构的水密舱壁为主要承力构件,其轴承孔周边区域为应力集中的主要区域,当荷载较大时,轴承孔周围会率先发生屈服破坏,因此,连接器带孔水密舱壁的材料强度是影响连接器整体极限强度的主要因素。 相似文献
6.
旨在研究声固耦合法模拟水下爆炸对圆筒的冲击,运用大型有限元软件 ABAQUS 声固耦合算法分别对密封圆筒与透水圆筒水下爆炸模型进行计算分析,并与理论公式结果进行对比分析。结果表明：利用 ABAQUS 声固耦合算法可以比较准确地模拟圆筒水下爆炸分析,能够满足工程要求;另外,在相同的水下爆炸作用下,透水圆筒比密封圆筒具有更好的抗爆炸和抗冲击性能。 相似文献
7.
氮化硅陶瓷具有密度小强度高的优点，在深潜浮力设备领域具有广阔发展前景。然而陶瓷材料固有的脆性以及万米深海严苛的工作环境，使得氮化硅陶瓷空心浮力球在深水环境下面临着内爆的风险。为探究氮化硅陶瓷空心浮力球在内爆临界状态下的失效问题，设计并进行了三点弯曲试验，确定了氮化硅陶瓷材料的力学性能参数，包括弹性模量和破坏应力；随后对氮化硅陶瓷空心浮力球内爆试验的过程及结果进行了回顾总结；基于标准球壳模型与浮力球实物的CT扫描几何模型，对浮力球在内爆临界状态的失效过程进行了有限元仿真分析。结果表明：氮化硅陶瓷空心浮力球的性能存在一定不稳定性；结构内表面局部过大的拉应力是造成失效的主要原因，对内表面进行预加压处理或能提高其抗内爆性能。 相似文献
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近年来,潮流能能量转换技术发展迅速,但大型潮流发电机组基础结构方面的研究和应用还并不多见。针对潮流能电站基础结构在抗弯抗剪强度、桩径尺寸方面的特殊要求,结合我国潮流能富集区海底多为浅覆盖层或裸露基岩、且地形复杂的情况,提出了一种新型模块式嵌岩灌注桩基础结构。该基础结构的嵌岩灌注桩通过在桩内布置环形钢板箍和钢筋束来增强抗剪抗弯能力,使其在常规桩径即可满足潮流能电站的支撑要求,减少了对发电水流断面的阻挡;各主体灌注桩可通过横撑、纵撑和斜撑连接构成模块式基础,以适应不同地形条件、不同机组数量和安装方式的要求。新型模块式嵌岩灌注桩基础结构在LHD联合动能公司3.4 MV潮流发电项目中进行了首次应用,获得了良好的使用反馈。 相似文献
10.
海上风机结构在运营期内可能面临极端风浪、地震等荷载作用。因此,极端工况作用下海上风机局部和整体结构反应将成为结构设计以及安全评价的重要参数。采用半整体方法,以桩基泥面最大位移、结构杆件极端承载力以及桩基抗压、抗拔承载力为判定指标,基于塑性可靠度理论,系统研究台风条件下运营期内海上风机基础结构可靠度指标变化规律,得出潜在的基础结构失效模式及相应判定指标。由研究可得,台风条件下运营期内海上风机基础结构各可靠度将显著受到基础冲刷、海生物生长和结构腐蚀的影响,并且结构失效模式将由单一模式破坏发展为多种模式联合失效。 相似文献
11.
密封压力是带压堵漏维修管卡的关键性能。介绍了323.9 mm(API 12英寸)维修管卡样机的总体结构及密封原理，选用接触压力准则作为管卡的密封评价准则，利用ANSYS Workbench软件建立了管卡密封结构的二维轴对称有限元模型，分析了密封结构闭环中薄弱部分在不同密封圈压缩量下的接触压力，然后试验测试了管卡样机密封圈压缩量和密封压力，并与有限元计算接触压力进行了对比。分析结果表明管卡密封结构最薄弱部分的接触压力随着周向密封圈压缩量的增大而增大，且主要是中间接触部分起到密封作用。通过试验验证了理论分析的管卡密封结构最薄弱位置，并发现相同密封圈压缩量下试验测试的密封压力与计算的接触压力近似，两者的变化趋势基本一致。有关分析思路和试验方法可以为管卡密封结构的设计提供重要参考。 相似文献
12.
深海腐蚀检测用水密电子舱设计 总被引：1，自引：0，他引：1
设计了一种可在300 m 水深条件下进行腐蚀电化学在线检测作业的水密电子舱, 它主要由耐压水密壳体以及集成在壳体外部的插接件式电极系统和多孔屏蔽罩组成。耐压壳体由圆柱形筒体和加强型平盖构成, 满足设计条件下的强度、密封、防腐要求。三电极系统采用水密接插件式设计, 安装在加强型平盖上; 电极系统与外部多孔罩组成开放屏蔽式电解池, 可在水下进行在线电化学测试。 相似文献
13.
Jeom Kee Paik Anil K. Thayamballi P. Terndrup Pedersen Young Il Park 《Ocean Engineering》2001,28(8):51
For a ship hull with large deck openings such as container vessels and some large bulk carriers, the analysis of warping stresses and hatch opening deformations is an essential part of ship structural analyses. It is thus of importance to better understand the ultimate torsional strength characteristics of ships with large hatch openings. The primary aim of the present study is to investigate the ultimate strength characteristics of ship hulls with large hatch openings under torsion. Axial (warping) as well as shear stresses are normally developed for thin-walled beams with open cross sections subjected to torsion. A procedure for calculating these stresses is briefly described. As an illustrative example, the distribution and magnitude of warping and shear stresses for a typical container vessel hull cross section under unit torsion is calculated by the procedure. By theoretical and numerical analyses, it is shown that the influence of torsion induced warping stresses on the ultimate hull girder bending strength is small for ductile hull materials while torsion induced shear stresses will of course reduce the ship hull ultimate bending moment. 相似文献
14.
This paper firstly figures out a similar scale model regarding ultimate strength experiment of a typical ultra large container ship (ULCS) through combined ultimate longitudinal bending and torsion analysis, in which the similarity theory is proposed to design the scale model for reflecting the progressive collapse behaviors of true ships in ultimate strength model test. The present study presents the similarity between scale model and true ship in cross-section considering the height of neutral axis, the section modulus, the inertia moment about neutral axis and the polar inertia moment should fit the geometrical similarity theory, and in strength considering buckling strength and shear ultimate strength of plates and stiffened panels should fit the strength similarity theory. Numerical investigations are conducted on the ultimate strength of a 10,000 TEU container ship and the similar scale model under pure hogging bending, pure torsion and combined bending and torsion, respectively. The nonlinear finite element method (NFEM) is adopted considering the effects of initial deformations and both material and geometric nonlinearities. Finally, the numerical results are compared with each other and discussed showing a good agreement in both elastic and inelastic range during the progressive collapse behaviors, which means the similar scale model can represent the true ship regarding ultimate strength test. And the similarity theory is verified quite stable after the uncertainty analysis. 相似文献
15.
Pipes inevitably encounter high ambient pressure and bending moment during the deepwater pipe-laying process,which can lead to elliptical buckling and even deterioration failure.For the safety of pipe-laying operation,available formalas for the pipe stability are established on the basis of the assumption of uniform deformation along the tube length and symmetrical buckling.This method can predict the nonlinear rcsponse of elliptical collapse of steel circular tubes for different ratios of diameter to thickness (D/t) under pure bending or combined bending and external pressure.In these formulas,the strain-displacement relationship is deduced from the nonlinear ring theory,and the Ramberg-Osgood constitutive model is applied to simulate the inelastic material behavior.Meanwhile,the principle of virtual work is adopted to derive the equilibrium equations.A set of equations is solved by the Newton-Raphson method,and the iterative scheme contains nested iteration for the constitutive relation.In order to check the effectiveness of this theoretical method,illustrative examples are presented in this paper.Besides,the numerical simulation is carried out by use of ANSYS.A comparison of the results shows that the theoretical method can provide reasonable prediction for engineering practice. 相似文献
16.
Combined conductivity-temperature-depth(CTD) casts and Argo profiles, 3 086 historical hydrocasts were used to quantify the water column characteristics in the northern South China Sea(SCS) and its adjacent waters. Based on a two-dimensional "gravest empirical mode"(GEM), a gravitational potential(, a vertically integrated variable) was used as proxy for the vertical temperature profiles TG(p,). integrated from 8 MPa to the surface shows a close relationship with the temperature, except in the deep layer greater than 15 MPa, which was caused by the bimodal deep water in the region. The GEM temperature profiles successfully revealed the bimodality of the Luzon Strait deep water, that disparate hydrophic vertical profiles can produce distinct specific volume anomaly() in the SCS and the western Philippine Sea(WPS), but failed in the Luzon Strait, where different temperature profiles may produce a same. A significant temperature divergence between the SCS water and the WPS water confirmed that the bimodal structure is strong. The deepwater bifurcation starts at about 15 MPa, and gets stronger with increasing depth. As the only deep channel connecting the bimodal-structure waters, water column characteristics in the Luzon Strait is in between, but much closer to the SCS water because of its better connectivity with the SCS. A bimodal temperature structure below 15 MPa reveals that there was a persistent baroclinic pressure gradient driving flow through the Luzon Strait. A volume flux predicted through the Bashi Channel with the hydraulic theory yields a value of 5.62×106 m3/s using all available profiles upstream and downstream of the overflow region, and 4.03×106and 2.70×106 m3/s by exclusively using the profiles collected during spring and summer, respectively. No volume flux was calculated during autumn and winter because profiles are only available for the upstream of the Bashi Channel during the corresponding period. 相似文献
17.
西非深水钻井实践与认识 总被引：1，自引：0，他引：1
JDZ B-1井是中石化作为作业者完成的第一口海洋深水探井,该井位于西非几内亚湾尼日利亚—圣多美和普林西比联合开发区内,作业水深1 655 m。井区地质情况较为复杂,地层破裂压力低,钻井作业压力窗口窄,井眼稳定性差。特别是该井目的层距海底泥线浅（只有778 m）以及目的层段长等,给钻井工程设计带来了诸多挑战。针对钻井施工中面临的挑战与深水钻井的特点,从井身结构设计到施工中均采取了合适的钻井技术和措施,有效地解决了问题,取全取准了各项资料,高效、优质地完成了该井的施工任务。该井的成功完钻,为中石化海洋深水钻井积累了经验,可供该区域及国内海洋深水钻井借鉴。 相似文献
18.
为研究高海水围压条件下截齿切削多金属硫化物(SMS)的动力学特性,根据深海环境构建了镐形单截齿破碎多金属硫化物的切削力数学模型,同时考虑海底多金属硫化物高孔隙、非线性等特点,选取合适的材料本构模型及其相关参数,基于LS-DYNA数值模拟平台,利用有限单元法建立高海水围压条件下截齿切削多金属硫化物的数值仿真模型,模拟了不同海水围压条件下多金属硫化物的切削破碎过程。研究结果表明:截齿上的海水围压对矿体破碎的影响很小,矿体上的海水围压对矿体破碎影响较大;在高海水围压条件下,多金属硫化物的强度明显增大,切屑更难从基岩剥离,截齿受到的三向阻力明显增大,高围压作用限制了截齿切削破碎过程中的振动,截齿载荷波动性显著减小。 相似文献
19.
Excited by ocean currents, random wave and vessel motion, deepwater drilling risers exhibit significant dynamic response. In time domain, a method is proposed to calculate the nonlinear dynamic response of deepwater drilling risers subjected to random wave and dynamic large displacement vessel motion boundary condition. Structural and functional loads, external and internal pressure, free surface effect of irregular wave, hydrodynamic forces induced by current and wave, as well as wave and low frequency (drift) motion of the drilling vessel are all accounted for. An example is presented which illustrates the application of the proposed method. The study shows that long term drift motion of the vessel has profound effect on the envelopes of bending stress and lateral displacement, as well as the range of lower flex joint angle of the deepwater riser. It can also be concluded that vessel motion is the principal dynamic loading of nonlinear dynamic response for the deepwater risers rather than wave force. 相似文献