根据分形理论设计一种分形防护装置,基于非线性动力学理论,采用ANSYS/LS-DYNA模拟5000 t船舶与设有不同阶数防护装置的4 MW海上风力机碰撞过程,分析研究不同阶数防护装置的防护效果。结果表明：较橡胶材料实心防护装置,分形防护装置可有效降低接触力,延长接触时间;分形结构可提高防护装置内能转化能力,促进外层钢壳吸能,并提升橡胶内能耗散;分形防护装置应力峰值更低,高应力区域更广,可使更大面积材料发挥防护作用,有效降低撞深。不同阶数分形结构的抗撞性能与分形孔受撞后变形状况有关,其中一阶分形结构提升防护装置抗撞性能最优。
Abstract
With the increasing number of offshore wind farms construction and most of them are in the busy channel, the probability of collision of wind turbines by ships increased extensively. A fractal protection device was designed using the fractal theory in this paper. Based on the nonlinear dynamics theory, ANSYS/LS-DYNA was used to simulate the collision process between a 5000 t ship and a 4 MW offshore wind turbine with different fractal order protection devices. The contact force, energy conversion, stress and collision depth were analyzed. The results show that the first, fractal protective devices can reduce the contact force by 3.93%, and can effectively extend the contact time compared with solid protective devices. In addition, the fractal structure can improve the internal energy conversion ability of the protective device, promote the energy absorption of the outer steel shell, and enhance the internal energy dissipation of rubber. Comparing with the solid one, the fractal protection device has a lower stress peak and a wider high stress zones, which can make more material play a protective role and effectively reduce the impact depth. The anti-collision performance of fractal structure of different order is related to the deformation of fractal hole after collision, and the first order fractal structure has the best protective performance.
关键词
海上风力机 /
分形 /
碰撞 /
防护装置
Key words
offshore wind turbines /
fractal /
collision /
protective device
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参考文献
[1] YUSTA J M, LACAL-ARÁNTEGUI R. Measuring the internationalization of the wind energy industry[J]. Renewable energy, 2020, 157: 593-604.
[2] 国家能源局. 2019年风电并网运行情况[EB/OL].(2020-02-28)http://www.nea.gov.cn/2020-02/28/c_138827910.htm.
National energy administration. integrated wind power in2019[EB/OL]. (2020-02-28)http://www.nea.gov.cn/2020-02/28/c_138827910.htm.
[3] 韩志伟, 李春, 周红杰, 等. 海上风力机基础防护装置在船舶碰撞下的动态响应研究[J]. 机械强度, 2020, 42(1): 21-28.
HAN Z W, LI C, ZHOU H J, et al.Research on dynamic response with crashworthy devices of offshore wind turbine fundation to ship impact[J]. Journal of mechanical strength, 2020, 42(1): 21-28.
[4] SHARPLES M, SHARPLES B J.Damage and critical analysis of accidents to assist in avoiding accidents on offshore wind farm on the OCS[R]. Report Prepared for Minerls Management Service, Department of the Interior, US. Project, 2010, 633.
[5] Caithness windfarm information forum. Wind turbine acctident compilation[EB/OL]. http://www.caithnesswindfarms.co.uk.html, 2010: 4-18.
[6] DERUCHER K N.Analysis of concrete bridge piers for vessel impact[J]. Civil engineering for practicing and design engineers, 1982, 1(4): 393-420.
[7] LIU B, GARBATOV Y, ZHU L, et al.Numerical assessment of the structural crashworthiness of corroded ship hulls in stranding[J]. Ocean engineering, 2018, 170: 276-285.
[8] VAUGHAN H.Bending and tearing of plate with application to ship bottom damage[J]. Naval architects, 1978, 3: 97-99.
[9] WANG J J, SONG Y C, WANG W, et al.Evaluation of flexible floating anti-collision device subjected to ship impact using finite-element method[J]. Ocean engineering, 2019, 178: 321-330.
[10] LEE K.Effects on the various rubber fenders of a tripod offshore wind turbine substructure collision strength due to boat[J]. Ocean engineering, 2013, 72: 188-194.
[11] 郝二通, 柳英洲, 柳春光.单桩基础海上风机受船撞击损伤和动力响应分析[J]. 大连理工大学学报, 2014, 54(5): 551-557.
HAO E T, LIU Y Z, LIU C G.Damage and dynamic response analyses of offshore wind turbine with monopile foundation subj ected to ship impact[J]. Journal of Dalian University of Technology, 2014, 54(5): 551-557.
[12] 韩志伟, 李春, 周红杰, 等. 海上风力机多层材料防护装置在船舶碰撞下动力响应分析[J]. 热能动力工程, 2019, 34(9): 148-155.
HAN Z W, LI C, ZHOU H J, et al.Dynamic response with Multi-layer material crashworthy devices of offshore wind turbine under ship collision[J]. Journal of engineering for thermal energy and power, 2019, 34(9): 148-155.
[13] WANG J, ZHANG Y, HE N, et al.Crashworthiness behavior of Koch fractal structures[J]. Materials and design, 2018, 144: 229-244.
[14] ZHANG Y, HE N, SONG X Y, et al.On impacting mechanical behaviors of side fractal structures[J]. Thin-walled structures, 2020, 146: 106490.
[15] GLADMAN B.LS-DYNA keyword user’s manual[M]. California: Livermore Software Technology Corporation, 2007: 108-110.
[16] LIM H K, LEE J S.On the structural behavior of ship’s shell structures due to impact loading[J]. International journal of naval architecture and ocean engineering, 2018, 10(1): 103-118.
[17] OGDEN R W.Nearly isotropic elastic deformations: application to rubberlike solids[J]. Journal of the mechanics and physics solids, 1978, 26(1): 37-57.
[18] 许腾飞, 王新峰, 郭树祥. 高弹性橡胶夹层结构封严板分析方法[J]. 南京航空航天大学学报, 2020, 52(3): 394-400.
XU T F, WANG X F, GUO S X, et al.Analytical method of sealed plate with hyperelastic rubber sandwich structure[J]. Journal of Nanjing University of Aeronautics & Astronautics, 2020, 52(3): 394-400.
[19] WU S.A variational principle for dynamic contact with large deformation[J]. Computer methods in applied mechanics and engineering, 2009, 198(21-26): 2009-2015.
[20] HE J H.Fractal calculus and its geometrical explanation[J]. Results in physics, 2018, 10: 272-276.
[21] BARNSLEY M F, DEMKO S.Iterated function systems and the global construction of fractals[C]//Proceedings of the Royal Society of London A: mathematical, physical and engineering sciences, London, UK, 1985: 243-275.
[22] HAO E T, LIU C G.Evaluation and comparison of anti-impact performance to offshore wind turbine foundations: monopile, tripod, and jacket[J]. Ocean engineering, 2017, 130: 218-227.
[23] 王自力, 蒋志勇, 顾永宁. 船舶碰撞数值仿真的附加质量模型[J]. 爆炸与冲击, 2002, 22(4): 321-326.
WANG Z L, JIANG Z Y, GU Y N.Additional mass model for numerical simulation of ship collision[J]. Explosin and shock waves, 2002, 22(4): 321-326.
[24] GLADMAN B.LS-DYNA keyword user’s manual[M]. California: Livermore Software Technology Corporation, 2007: 1307-1312.
漆安慎, 杜婵英. 力学[M]. 北京: 高等教育出版社,1997: 86-87.
25 QI A S, DU C Y.Dynamics[M]. Beijing: Higher Education Press, 1997: 86-87.
基金
国家自然科学基金（51976131; 52006148）; 上海市“科技创新行动计划”地方院校能力建设项目（19060502200）
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