摘要
叶片作为风力发电机的捕风部件,其重要性是不言而喻的。研究如何保证叶片的结构可靠性,提高气动效率,同时又尽量减少叶片的成本,显然具有十分现实的工程价值和学术意义。
目前,国内外研究主要是将铺层结构强度作为评定叶片结构可靠性的一个指标,而没有深入研究风载荷作用下叶片铺层结构的应力场分布特性及其对叶片不同结构区域强度的影响。研究表明,基于欧拉伯努利梁理论初步铺层设计方法获得的铺层结构在叶根严重不满足实际强度的要求。正是基于此,本文研究了叶片复合材料铺层结构的强度特性,不同铺层纤维角度对铺层结构强度的影响,最后基于试验设计法,实现了铺层结构优化设计,从而为铺层结构优化设计方法研究提供基础,其主要研究内容和结论如下:
(1)基于复合材料有限法和Tsai-Wu强度失效准则,开展了叶片有限元几何建模方法的研究,研究了铺层结构定义和复合材料Tsai-Wu强度失效准则在有限元方法中的实现。
(2)设计了包含多种纤维角度的铺层方案,研究了各种铺层方案下在多个截面节点处沿铺层厚度分布的Tsai-Wu强度指标分布规律,进一步研究了铺层纤维角度对叶片三个不同结构特征区域强度的影响。结果表明,铺层纤维角度对叶片各个区域的强度的影响具有明显的差异性,铺层纤维角度的优化设计应考虑叶片不同结构特征区域。
(3)进行了多种风速下叶片结构的静态应力响应分析,重点研究了叶根截面节点处沿铺层厚度分布的应力和位移分布规律,结合复合材料Tsai-Wu失效准则,研究了叶根铺层强度特性,详细剖析了基于欧拉伯努利梁理论进行铺层初步设计在叶根不适用的原因。分析表明,叶根不满足平面假设,面内其它应力分量(面内横向正应力和切应力)是影响叶根强度的主要因素,铺层结构设计方法必须考虑面内其它应力分量。
(4)针对基于欧拉伯努利梁理论初步铺层设计方法获得的叶根强度严重不满足的叶片,基于试验设计法,设计了多种铺层方案,以Tsai-Wu强度指标值为评定指标,对该叶片进行了多次有限元模拟试验,以铺层数量最少为设计目标,实现了叶片铺层结构优化设计。同时,基于极差分析法,探讨了0°铺层和±45°铺层对叶片结构强度的影响,结果表明0°和±45°两类铺层对叶片结构强度的影响存在耦合作用;±45°铺层对叶片结构强度影响较大。
The importance of Wind turbine blades as components for catching the wind power is self-evident. And it obviously has the significance of the engineering practice and scientific value to solve the problem, how to minimize the blade’s cost on the basis of structural integrity and high aerodynamic efficiency, while it is necessary for figure out this problem to have better knowledge and understanding of strength properties of the blade composite ply structure. Present research situation of home and abroad mainly treat the strength of ply structure as the measure of the structural integrity of a blade and there is no further study about the stress distribution between internal ply of the blade and the influence by the stress components on the strength of the ply structure, the influence by ply angle on the different structural regions. Moreover, the current preliminary design method of the ply structure based on Bernoulli-Euler beam theory proposed by some scholars does not meet the actual strength requirements. Consequently, this paper analyzes the structural strength of composite ply properties, the influence on the strength of ply structure by ply angles and finally the ply structure is optimized based on the method of experimental design, so as to provide research-based optimization method for lay structure. The main contents of this paper and conclusions are as follows:
(1) As the contents of this study is expanded by the basis of composite strength of law and the Tsai-Wu failure criteria, thus, we firstly give the method of the geometric modeling for the blade and how to define ply structure and Tsai-Wu failure criterion of strength.
(2) In order to study the influence on the strength for three regions with different structural characteristics of the blade by the ply angle, the blade of finite element model is established, a variety of ply angle is designed, the Tsai-Wu strength index values of the nodes, under different ply schedules, along the ply thickness at several sections is extracted. The result shows that ply angle of the blades has specific affect on each region of blade, optimization of ply angle need to consider the existence of different structural features of the whole blade.
(3) In order to research and analyze, for the blade root, the strength properties and the reason of the fact, that the preliminary design method of the ply structure based on Bernoulli-Euler beam theory proposed by some scholars does not meet the actual strength requirements, the blade of finite element model is modeled, static structural response of the blade is simulated at various wind speed, the stress and displacement components of the nodes along the ply thickness at several sections of the root is extracted. The result, with the use of Tsai-Wu failure criterion, shows that the sections of the root do not meet the plane hypothesis, in-plane stress components (In-plane transverse normal stress and shear stress) are the main factor affecting the root strength, and that the method of ply structure design should consider the in-plane stress components.
(4) Through Design of Experiment with the design objective to minimize the amount of the plies, Various ply schedules is made and many finite element models of the blades is simulated, finally, the ply structure, designed by the ply preliminary design method based on Bernoulli-Euler beam theory, of the blade with the strength not meeting the acquirement at the root is optimized. Moreover, the influence by 0°plies and±45°plies on the blade structural strength is discussed, the result shows the coupling is existed between the influence by 0°plies and±45°plies on the strength, and that±45°ply is the main factor affecting the blade structural strength.
引文
[1]张坤民,潘家华,崔大鹏.低碳经济论[M].北京:中国环境科学出版社, 2008.
[2]牛山泉,刘薇,李岩.风能技术[M].北京:科学出版社, 2009.
[3]国际电力网. 2011风电行业全球市场准入技术研讨会在京召开[EB/OL]. http://power.in-en.com/html/power-09070907761162578.html.
[4]中国经济网.中国风力发电装机容量首次超美国全球遥遥领先[EB/OL]. http://ny.china.com.cn/2011-01/25/content_4263238.htm.
[5] Tony B,武鑫.风能技术[M].北京:科学出版社有限责任公司, 2011.
[6] James F.M, Jon G.M, Anthony L.R. Wind energy explained-theory, design and application[M]. West Sussex: John Wiley & Sons Ltd, 2010.
[7] Derek S.Berry, Tom Ashwill. CX-100 Manufacturing Final Project Report [R]. Sandia National Laboratories: 2007.
[8] Derek S.Berry, Tom Ashwill. TX-100 Manufacturing Final Project Report [R]. Sandia National Laboratories: 2007.
[9]张锦南. 300kW大型风力机叶片设计[J].材料导报, 2001, 15(2): 59-60.
[10] Bechly M.E, Clansen P.D. Structural design of a composite wind turbine blade using Finite element analysis[J]. Computers&Structures, 1997, 63(3): 639-646.
[11]黄争鸣.大型复合材料风力机叶片及其制备方法[P].中国: 200510023488, 2005-10-23.
[12] Mark E.T. Structural analysis of polymeric composite materials[M]. New York: CRC Press, 2003.
[13]沈观林,胡更开.复合材料力学[M].北京:清华大学出版社, 2006.
[14] Mark E.T. Structural analysis of polymeric composite materials[M]. New York: CRC Press, 2003.
[15] Mansour H. Mohamed, Kyle K. Wetzel. 3D Woven Carbon/Glass Hybrid Spar Cap for Wind Turbine Rotor Blade[J]. American Society of Mechanical Engineers, 2006, 128: 562-573.
[16] Hai C.Lin. Layup Analyzing of a Carbon/Glass Hybrid Composite Wind Turbine Blade Using Finite Element Analysis[J]. Applied Mechanics and Materials, 2011, 87: (49-54).
[17] Daniel D. Samborsky, Timothy J. Wilson, John F. Mandell. Comparison of Tensile Fatigue Resistance and Constant life diagrams for several potential wind turbine blade laminates[J]. Journal of Solar Energy Engineering, 2009, 131(1): 1-18.
[18] Herbert J. Sutherland, John F. Mandell. Optimized constant life diagram for the analysis of fiberglass composites used in wind turbine blades[J]. Journal of Solar Energy Engineering: 2005, 127: 563-569.
[19] Rajadurai J. Selwin1; Thanigaiyarasu G. Failure envelope generation using modified failure criteria for wind turbine blade and validation for FRP laminates[J]. Mechanics of Advanced Materials and Structures, 2009, 16(4): 275-292.
[20] Christoph W. Kensche. Fatigue of composites for wind turbines[J]. International Journal of Fatigue, 2006, 28, 1363-1374.
[21]张畅,秦泽云,李慧,张彦飞,杜瑞奎,刘亚青.风机叶片用玻璃纤维的渗透性研究[J].工程塑料应力, 2011, 39(6): 64-67.
[22]秦泽云,张彦飞,赵贵哲,杜瑞奎.风机叶片用环氧树脂体系流变性能研究[J].玻璃钢/复合材料, 2011, (3): 34-37.
[23]齐大伟,宁荣昌,凌辉.风机叶片真空吸塑成型(VRAM)工艺的研究[J].中国胶粘剂, 2008, 17(6): 50-56.
[24] Kam T.Y., Su H.M. Wang B.W. Development of glass-fabric composite wind turbine blade[J]. Advanced Materials Research[J]. 2011, 308-310: 2482-2485.
[25] Habali S.M; Saleh I.A. Local design, testing and manufacturing of small mixed airfoil wind turbine blades of glass fiber reinforced plastics. Part II: manufacturing of the blade and rotor[J]. Energy Conversion and Management, 2000, 41(3): 281-298.
[26] Jureczko M., Pawlak M., Mezyk A.. Optimisation of wind turbine blades[J]. Journal of Materials Processing Technology, 2005, 167(2-3): 463-471.
[27] Akira T, Yuki K. Structural design for CF/GF hybrid wind turbine blade using multi objiective genetic algorithm and kriging model RSM[J]. American Institute of Aeronautics and Astronautics, 2007, 2890-2896.
[28] Wu Wen-Hsiang; Young Wen-Bin. Structural Analysis and Design of the Composite Wind Turbine Blade[J]. Applied Composite Materials, 2011, 1-11.
[29] Bir G.S, Migliore P.G. Computerized method for preliminary structural design of composite wind turbine blades[J]. Journal of solar energy engineering, 2001, 123(4): 372–381.
[30] Tom Ashwill. Blade Technology Innovations for Utility-Scale Turbines[R]. Sandia National Laboratories: 2006.
[31] Ki-Hak Lee, Kyu-Hong Kim, Dong-Ho Lee, Kyung-Tae Lee, Kyung-Tae Lee, Jong-Po Park. Two Step optimization for Wind turbine blade with probability approach[J]. Journal of Solar Energy Engineering, 2010, 132(3): 0345031-0345035.
[32] Wangyu L., Jiaxing G., Xifeng L., Xin Z.. A kind of innovative design methodology of wind turbine blade based on natural structure[J]. 2009 2nd International Conference on Information and Computing Science, ICIC 2009, 2009, 4: 350-354.
[33] C. Beggreen, K. Banner, J. F. Jensen, J. P. Schultz. Application and Analysis of Sandwich Elements in the Primary Structure of Large Wind Turbine Blades[J]. Journal of Sandwich Structures and Materials, 2007, 525-552.
[34] Hahn F., Kensche C.W.; Paynter R.J.H., Dutton A.G., Kildegaard C., Kosgaard J. Design, fatigue test and NDE of a sectional wind turbine rotor blade[J]. Journal of Thermoplastic Composite Materials, 2002, 15(3): 267-277.
[35] Kong C., Bang J., Sugiyama Y. Structural investigation of composite wind turbine blade considering various load cases and fatigue life[J]. Energy, 2005, 30(11-12): 2101-2114.
[36] IEC 61400-1, Wind turbine generator system—Part I: safety requirements[S]. 2005
[37] Amano R.S., Malloy Ryan J. Aerodynamic comparison of straight edge and swept edge wind turbine blade[J]. ASME International Mechanical Engineering Congress and Exposition, Proceedings, 2009, 5: 193-197.
[38] Cai C. Liao, Wang J. Li, Shi K. Zhong, Xu J. Zhong. Optimization design on wind turbine blade sectional stiffness[J]. Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics, 2010, 37(7): 1127-1130.
[39] L.C.T. Overgaard, E. Lund, O.T. Thomsen. Structural collapse of wind turbine blade PART A static test and equivalent single layered models[J]. Composites Part A: Applied Science and Manufacturing, 2010, 41(2): 257-270.
[40] Ishida Yukio, Inoue Tsuyoshi; Nakamura Kohei. Vibration of a wind turbine blade ( theoretical analysis and experiment using a single rigid blade model)[J]. Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C, 2008, 74(5): 1056-1064.
[41] Tingrui L., Yongsheng R.. Aeroelastic stability analysis of wind turbine blade sections[J]. 1st International Conference on Sustainable Power Generation and Supply, SUPERGEN '09. 2009.
[42] Liu Xiong, Chen Yan, Ye Zhiquan. Research on the aerodynamic performance prediction model forhorizontal axis wind turbine[J]. 1 Institute of Energy Science, Shantou University, Shantou 515063, China. 2005, 26(6): 792-800.
[43] Jiacong Yin, Yu Xie, Pu Chen. Modal Analysis Comparison of Beam and Shell model for composite blades[J]. 2009 Asia-Pacific Power and Energy Engineering Conference, APPEEC 2009– Proceedings, 2009.
[44] Yan X., Wenlei S., Jianping Z.. Dynamic analysis of wind turbine blade based on reverse engineering[J]. Key Engineering Materials, 2011, 462-463: 1075-1079.
[45] de W.C. Goeij , van M.J.L. Tooren, Beukers A.. Implementation of bending-torsion coupling in design of wind turbine blade[J]. Applied Energy, 1999, 63(3): 191-207.
[46] Yinhu Q., Jiang H., Chunyan Z., Chen, Jie ping. Modeling Smart Structure of Wind Turbine Blade[J]. Applied Composite Materials, 2011, 1-8.
[47] Wangyu L., Yong Z. Bend-Twist Coupling Design and Evaluation of Spar Cap of Wind Turbine Compliance Blade[J]. Advanced Materials Research, 2010, 139-141, 1400-1405.
[48] Alejandro D. Otero, Fernando L. Ponta. Structural analysis of wind turbine blades by a generalizaed Timoshenko beam model[J]. Journal of Solar Energy Engineering, 2010, 132: 0110151- 011015-8.
[49] Hodges, D.H., Atilgan, A.R., Cesnik, C.E.S., Fulton, M.V. On a Simplified Strain Energy Function for Geometrically Nonlinear Behaviour of Anisotropic Beams[J]. Composites Engineering, 1992, 2(5-7): 513-536.
[50] Yu W., Hodges D.H., Volovoi V, Cesnik C.E.S. On Timoshenko-Like Modeling of Initially Curved and Twisted Composite Beams[J]. International Journal of Solids and Structures, 2002, 39(19): 5101-5121.
[51] J Wang, D Qin, Q Zhang. Mathematical model for predicting the blade behaviour of horizontal axis wind turbine[J]. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2008, 222(9): 1661-1694.
[52] Hoogedoorn Eelco, Jacobs Gustaaf B. Beyene Asfaw. Aero-elastic behavior of a flexible blade for wind turbine application: A 2D computational study[J]. Energy, 2010, 35(2): 778-785.
[53]李成良,王继辉,薛忠民,李军向.基于ANSYS的大型风机叶片建模研究[J].玻璃钢/复合材料, 2009, (2): 52-55.
[54]李德源,叶枝全,陈严,包能胜.风力机玻璃钢叶片疲劳寿命分析[J].太阳能学报, 2004, 25(5): 592-598.
[55] Daniel L.L, Felicia C.M. Finite Element Modeling of Wind Turbine Blades[J]. 43rd AIAA Aerospace Sciences Meeting and Exhibit, 2005, (6): 10-13.
[56]宗楠楠,董湘怀.小型风力机叶片强度的有限元分析[J].太阳能学报, 2010, 31(6): 764-768.
[57] Daniel R. Pardo, Kim B.. Finite element analysis of the cross-section of wind turbine blades: A comparison between shell and 2D-solid models[J]. Wind Engineering, 2005, 29(1): 25-32.
[58] Diego. C, Alejandro A. Escárpita, Hugo E., Juan J. Aguirre, Ahuett Horacio, Marzocca Piergiovanni, Probst Oliver. Numerical validation of a finite element thin-walled beam model of a composite wind turbine blade[J]. Wind Energy, 2011.
[59] Mandell John F., Cairns Douglas S., Samborsky Daniel D., Morehead Robert B., Haugen Darrin H. Prediction of delamination in wind turbine blade structural details[J]. ASME 2003 Wind Energy Symposium, WIND2003, 202-213.
[60]毛火军,石可重,汪仲夏.基于CFD和BEM方法的风电叶片强度分析比较[J].太阳能学报, 2009, 30(9): 1276-1279.
[61] Resor, Brian, Paquette Joshua, Laird Daniel, Griffith D. Todd. An evaluation of wind turbine blade cross section analysis techniques[J]. 51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, 2010.
[62] Liu Wei, Ma Yuli, Su Xianyue, Huang Kefu. Buckling analysis of wind turbine blade using pressuredistributions obtained from CFD[J]. 2009 Asia-Pacific Power and Energy Engineering Conference, APPEEC 2009– Proceedings.
[63]刘旺玉,张海全,曾琳.基于响应面法的仿生风力机叶片可靠性分析[J].太阳能学报, 2010, 31(9): 1204-1208.
[64] Henrik Stensgaard Toft, Kim Branner, Peter Berring, John Dalsgaard S?rensen. Defect distribution and reliability assessment of wind turbine blades[J]. Engineering Structures, 2011, 33(1): 171-180.
[65] Marin J. C., Barroso A., Paris F., Canas J.. Study of damage and repair of blades of a 300 kW wind turbine[J]. Energy: 2008, 33: 1068-1083.
[66] Wang X., Yuxiu X., Chuang M.. Large wind turbine blade layer design and dynamics characteristics analysis[J]. Applied Mechanics and Materials, 2010, 29-32: 1615-1621.
[67] Duan Wei, Zhao Feng. Loading analysis and strength cacluation of wind turbine blade based on blade element momentum theory and finite element method[J]. 2010 Asia-Pacific Power and Energy Engineering Conference, APPEEC 2010– Proceedings.
[68] Ladean R M, Douglas S C, et al. Analysis of a Composite Blade Design for the AOC 15/50 Wind Turbine Using a Finite Element Model [R]. Sandia National Laboratories: 2001.
[69] Sodena P D, Kaddourb A S, Hinton M J. Recommendations for designers and researchers resulting from the world-wide failure exercise [J]. Composites Science and Technology, 2004, (64): 589–604.
[70] Selwin Rajadurai J, Christopher T, et al. Finite element analysis with an improved failure criterion for composite wind turbine blades [J]. Forsch Ingenieurwes, 2008, (72): 193–207.
[71] Soden P.D, Hinton M.J, Kaddour A.S. Recommendations for designers and researchers resulting from the world-wide failure exercise[J]. Composites Science and Technology, 2004, 64(3-4): 589-604.
[72]陶梅贞,赵美英.国防科工委"十五"规划教材?复合材料结构力学与结构设计[M].陕西:西北工业大学, 2007.
[73]杨乃宾,梁伟.大飞机复合材料结构设计导论[M].北京:航空工业出版社, 2009.
[74]仝立勇,莫里茨,班尼斯特,黄涛,矫桂琼. 3D纤维增强聚合物基复合材料[M].北京:科学出版社, 2008.
[75] Michael W. Lai, David R., Erhard K.. Introduction to Continuum Mechanics[M]. Netherlands: Elsevier, 2009.
[76]冯云桢,葛东云,陆明万.连续介质力学初级教程[M].北京:清华大学出版社, 2009.
[77]刘鸿文.材料力学[M].北京:高等教育出版社, 2011.
[78]孙训方.材料力学[M].北京:高等教育出版社, 2002.
[79] Ansys Inc. ANSYS 13.0 help document.
[80] Mandell J.F, Samborsky D.D. DOE/MSU composite material fatigue database: test methods, materials, and analysis[R]. New Mexico: Sandia National Laboratories, 1997.
[81]袁志发,周静芋.试验设计与分析[M].北京:高等教育出版社, 2001.
[82]田胜元,萧曰嵘.实验设计与数据处理[M].北京:中国建筑工业出版社, 1988.