Hashin Failure Theory Based Damage Assessment Methodology of Composite Tidal Turbine Blades and Implications for the Blade Design

A damage assessment methodology based on the Hashin failure theory for glass fiber reinforced polymer (GFRP) composite blade is proposed. The typical failure mechanisms including the fiber tension/compression and matrix tension/compression are considered to describe the damage behaviors. To give the flapwise and edgewise loading along the blade span, the Blade Element Momentum Theory (BEMT) is adopted. In conjunction with the hydrodynamic analysis, the structural analysis of the composite blade is cooperatively performed with the Hashin damage model. The damage characteristics of the composite blade, under normal and extreme operational conditions, are comparatively analyzed. Numerical results demonstrate that the matrix tension damage is the most significant failure mode which occurs in the mid-span of the blade. The blade internal configurations including the box-beam, I-beam, left-C beam and right-C beam are compared and analyzed. The GFRP and carbon fiber reinforced polymer (CFRP) are considered and combined. Numerical results show that the I-beam is the best structural type. The structural performance of composite tidal turbine blades could be improved by combining the GFRP and CFRP structure considering the damage and cost-effectiveness synthetically.     

海洋纤维增强柔性管压溃失效特性研究及参数敏感性分析

以一种黏结型的纤维增强柔性管作为研究对象,基于ABAQUS建立纤维增强柔性管的实体单元模型。根据二维 Hashin失效判据判断柔性管失效情况,充分考虑管道内外护套层塑性及纤维增强层复合材料渐进失效,建立纤维增强柔性管的压溃数值模型。将特征值法与弧长法相结合,计算得到了较为精准的纤维增强柔性管临界压溃压力及对应的外压—椭圆度曲线;并对影响柔性管临界压溃压力的几个敏感性参数如椭圆度、纤维缠绕角度、直线度进行分析。研究结果表明椭圆度和直线度偏差的增大及纤维缠绕角度的降低均会使柔性管的临界压溃压力下降,该结果对纤维增强柔性管的设计与使用均具有一定的参考意义。