砂质海床中船锚运动全过程数值模拟
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摘要
基于SPH(光滑粒子流体动力学法)耦合FEM(有限元法)的算法,利用ANSYS/LS-DYNA软件对船锚在砂质海床土体中的运动全过程(抛锚与拖锚)进行了数值模拟,着重分析了海床土体基质和拖曳速度对船锚贯入深度与拖曳力的影响规律.研究表明:船锚运动全过程可分为4个阶段;随着土体材料剪切模量、内聚力、内摩擦角逐渐增大,最大贯入深度呈线性减小的趋势,除密实细砂海床土体外峰值拖曳力逐渐增大;在一定范围内孔隙率与最大贯入深度正相关,但孔隙率对峰值拖曳力的影响较小;随着拖曳速度的增加,峰值拖曳力提高幅度较大,但最大贯入深度变化不明显.此外,通过对比本文贯入深度模拟值与相关文献的试验值和理论计算值,验证了数值模型的准确性与可靠性.此研究结果可为海底电缆防护工程的设计和安全评估提供依据.
A numerical simulation of the whole movement process of an anchor in sandy seabed soil is carried out by using ANSYS/LS-DYNA software based on the coupling algorithm of smoothed particle hydrodynamics(SPH)and finite element method(FEM).The influence of seabed and dragging velocity on the penetration depth and dragging force of an anchor is analyzed.The research results show that the whole movement process of an anchor can be devided into four stages;with the shear modulus,soil cohesion and friction angle increases,the maximum penetration depth of an anchor decreases linearly;while the peak dragging force increases gradually except dense fine sandy seabed.In a certain range,the porosity and the maximum penetration depth are in a positive correlation.But the porosity has little influence on the peak dragging force.With the increase of the dragging velocity,peak dragging force increases while the maximum penetration depth does not change obviously.In addition,the numerical model is verified by comparing the simulation values of maximum penetration depth with both experimental and analytical results reported in literature.The simulation results can serve as a reference for the design and safety assessment of submarine cable protection programs.
A numerical simulation of the whole movement process of an anchor in sandy seabed soil is carried out by using ANSYS/LS-DYNA software based on the coupling algorithm of smoothed particle hydrodynamics(SPH)and finite element method(FEM).The influence of seabed and dragging velocity on the penetration depth and dragging force of an anchor is analyzed.The research results show that the whole movement process of an anchor can be devided into four stages;with the shear modulus,soil cohesion and friction angle increases,the maximum penetration depth of an anchor decreases linearly;while the peak dragging force increases gradually except dense fine sandy seabed.In a certain range,the porosity and the maximum penetration depth are in a positive correlation.But the porosity has little influence on the peak dragging force.With the increase of the dragging velocity,peak dragging force increases while the maximum penetration depth does not change obviously.In addition,the numerical model is verified by comparing the simulation values of maximum penetration depth with both experimental and analytical results reported in literature.The simulation results can serve as a reference for the design and safety assessment of submarine cable protection programs.
引文
[1]张国光.海底电缆安全及其施工埋设技术研究[J].海洋技术,1992,(1):64-73.Zhang Guoguang.Research on safety and construction technology of submarine cable[J].Ocean Technology,1992,(1):64-73.
[2]王彦多.法向承力锚的初始入土深度研究[D].天津:天津大学,2008.Wang Yanduo.Study on initial embedment depth of normal bearing anchor[D].Tianjin:Tianjin University,2008.
[3]马红旗.鱼雷锚初始贯入海床深度的研究[D].天津:天津大学,2010.Ma Hongqi.Study on the initial penetration depth of torpedo anchor[D].Tianjin:Tianjin University,2010.
[4]张磊.基于船舶应急抛锚的海底管道埋深及保护研究[D].武汉:武汉理工大学,2013.Zhang Lei.Study on buried depth and protection of submarine pipeline based on ship emergency anchoring[D].Wuhan:Wuhan University of Technology,2013.
[5]张鹏杨,王瑛剑,柯超,等.基于ABAQUS的船舶抛锚贯入深度的分析[J].光纤与电缆及其应用技术,2016,(4):32-35.Zhang Pengyang,Wang Yingjian,Ke Chao,et al.Analysis of anchoring penetration depth based on ABAQUS[J].Optical Fiber&Electric Cable and Their Applications,2016,(4):32-35.
[6]中华人民共和国国家质量监督检验检疫总局,中国国家标准化管理委员会.GB/T546-1997霍尔锚[S].北京:中国标准出版社,1997.General Administration of Quality Supervision,Inspection and Quarantine of the People’s Republic of China,Standardization Administration of the People’s Republic of China.GB/T546-1997 Hall Anchor[S].Beijing:Standards Press of China,1997.
[7]Johnson G R,Stryk R A,Beissel S R.SPH for high velocity impact computations[J].Comput Methods Appl Mech Engrg,1996,(139):347-373.
[8]Trautmann C H,Kulhawy F H.A computer program for compress and uplift foundation analysis and design[R].Electrical Power and Research Institute,1987.
[9]Abbo A J,Sloan S W.A smooth hyperbolic approximation to the Mohr-Coulomb yield criterion[J].Computers and Structures,1995,54(3):427-551.
[10]Klisinski M.Degradation and plastic deformation of concrete[D].Polish:Polish Academy of Sciences,1984.
[11]Klisinski M,Mroz Z.Description of inelastic deformation and degradation of concrete[J].International Journal of Solids and Structures,1988,24(4):391-416.
[12]Ju J W.Energy-based coupled elastoplastic damage models at finite strains[J].Journal of Engineering Mechanics,1989,115(11):2507-2525.
[13]宣凯.抛锚作业对海底管线损害研究[D].大连:大连海事大学,2012.Xuan Kai.The study on anchoring damage to subsea pipelines[D].Dalian:Dalian Maritime University,2012.
[2]王彦多.法向承力锚的初始入土深度研究[D].天津:天津大学,2008.Wang Yanduo.Study on initial embedment depth of normal bearing anchor[D].Tianjin:Tianjin University,2008.
[3]马红旗.鱼雷锚初始贯入海床深度的研究[D].天津:天津大学,2010.Ma Hongqi.Study on the initial penetration depth of torpedo anchor[D].Tianjin:Tianjin University,2010.
[4]张磊.基于船舶应急抛锚的海底管道埋深及保护研究[D].武汉:武汉理工大学,2013.Zhang Lei.Study on buried depth and protection of submarine pipeline based on ship emergency anchoring[D].Wuhan:Wuhan University of Technology,2013.
[5]张鹏杨,王瑛剑,柯超,等.基于ABAQUS的船舶抛锚贯入深度的分析[J].光纤与电缆及其应用技术,2016,(4):32-35.Zhang Pengyang,Wang Yingjian,Ke Chao,et al.Analysis of anchoring penetration depth based on ABAQUS[J].Optical Fiber&Electric Cable and Their Applications,2016,(4):32-35.
[6]中华人民共和国国家质量监督检验检疫总局,中国国家标准化管理委员会.GB/T546-1997霍尔锚[S].北京:中国标准出版社,1997.General Administration of Quality Supervision,Inspection and Quarantine of the People’s Republic of China,Standardization Administration of the People’s Republic of China.GB/T546-1997 Hall Anchor[S].Beijing:Standards Press of China,1997.
[7]Johnson G R,Stryk R A,Beissel S R.SPH for high velocity impact computations[J].Comput Methods Appl Mech Engrg,1996,(139):347-373.
[8]Trautmann C H,Kulhawy F H.A computer program for compress and uplift foundation analysis and design[R].Electrical Power and Research Institute,1987.
[9]Abbo A J,Sloan S W.A smooth hyperbolic approximation to the Mohr-Coulomb yield criterion[J].Computers and Structures,1995,54(3):427-551.
[10]Klisinski M.Degradation and plastic deformation of concrete[D].Polish:Polish Academy of Sciences,1984.
[11]Klisinski M,Mroz Z.Description of inelastic deformation and degradation of concrete[J].International Journal of Solids and Structures,1988,24(4):391-416.
[12]Ju J W.Energy-based coupled elastoplastic damage models at finite strains[J].Journal of Engineering Mechanics,1989,115(11):2507-2525.
[13]宣凯.抛锚作业对海底管线损害研究[D].大连:大连海事大学,2012.Xuan Kai.The study on anchoring damage to subsea pipelines[D].Dalian:Dalian Maritime University,2012.