基于复合材料铺层的兆瓦级风力机叶片结构性能分析

Performance Analysis of Megawatt Wind Turbine Blade Structure based on Composite Material Layers

采用参数化建模,建立多种复合材料叶片三维有限元壳体模型,并对叶片进行模态分析。进一步采用流固耦合方法,实现叶片表面气动载荷加载,对额定工况下的叶片进行屈曲分析。以初步设计的5MW风力机叶片为例,研究结果表明:复合材料具有明显的各向异性;铺层纤维角度影响叶片整体固有频率,合理的铺层结构可使叶片低阶固有频率远离激振频率,防止叶片发生共振破坏;复合材料铺层叶片在额定工况下不会发生整体屈曲破坏,但因复合材料抗拉抗压性能不同,在压缩载荷作用下叶片背风面几何突变区出现局部屈曲,在叶片设计制造时应该充分加以考虑,以防止局部屈曲破坏。

Parametric modeling technique is developed to build the three-dimensional finite element shell model of a preliminarily designed large scale wind turbine composite blade.The aerodynamic load on the blade surface was calculated by fluid-structure coupling method,and the buckling of composite blades under the rated condition was carried out.Taking the blade of 5 MW wind turbine for example,the results show that proper composite ply structure has the obvious anisotropy.The angle of the ply fibers affects the inherent frequency of the whole blade.The reasonable ply structure can keep the inherent frequency of blades far away from the excitation frequency and prevent the resonance of blades.Composite blades cannot fail by buckling at the rated condition.However,under the compressive load,local buckling appears in the geometric mutation area of blades,because of the difference between tensile and compressive properties of the composite materials.In blade design and manufacture,local buckling should be taken into consideration to prevent local buckling failure.