Influence of Mechanical Properties on Modal Analysis of Natural Fiber Reinforced Laminated Composite Trapezoidal Plates

ABSTRACT

Present work concentrates on modal parameters of laminated composite plates composed of natural fibers reinforced with unsaturated polyester resin. The selected jute and ramie fibers underwent alkaline treatment to improve mechanical properties. Upon compression molding, the laminated composite plates such as ramie/polyester (R plate), jute/polyester (J plate) and combination of ramie and jute (RJ plate) are fabricated. The physical, mechanical and elastic properties are calculated as per ASTM standards. Using obtained elastic properties, the free undamped vibration analysis of composite plates are computed using finite element software ANSYS 18.1 for trapezoidal plates, with respect to a/b = 1 and 2, c/b = 0.25 to 1 and a/h = 50. The natural frequency and mode shape of the plates are obtained for various boundary conditions such as CFFF, CFCF, CCCC, SFSF and SSSS (C-Clamped, F-Free and S-Simply supported). The dimensionless frequency and mode shapes of R, J and RJ plates are compared with literatures which are in good agreement.

摘要

研究了不饱和聚酯树脂增强天然纤维复合材料层合板的模态参数. 选用黄麻和苎麻纤维进行碱处理，以提高力学性能. 采用模压成型的方法，制备了苎麻/聚酯（R板）、黄麻/聚酯（J板）和苎麻/黄麻组合（RJ板）等复合材料层合板. 物理、机械和弹性性能按ASTM标准计算. 利用获得的弹性特性，利用有限元软件ANSYS 18.1对梯形板进行了a/b=1&2，c/b=0.25～1，a/h=50的自由无阻尼振动分析. 在不同的边界条件下，得到了板的固有频率和振型，如CFFF、CFI、CCCC、SFSF和SSSS（C-固支、F-自由和S-简支）。将R、J、RJ板的无量纲频率和振型与文献进行了比较，结果吻合较好.

KEYWORDS:

• Composites
• modal analysis
• mode shape
• natural fiber
• non dimensional frequency parameter
• finite element method
• vibration analysis

关键词:

• 复合材料
• 模态分析
• 振型
• 天然纤维
• 无量纲频率参数
• 有限元法
• 振动分析