Modal Analysis of Functionally Oriented Fabric Laminate with 10 mm Wide Carbon Strips and a 20 mm Circular Notch

Functionally oriented fabric (FOF) is a woven textile featuring irregularly but not randomly integrated functional material strips in both warp and weft directions, designed to locally improve the mechanical properties of laminates. Low-cost material such as glass fiber is combined with high mechanical properties material such as carbon fiber. The subject of this work is to analyze the effect of two FOF laminate layups on natural frequencies of the laminate with a notch using finite element method and experimental evaluation. The layups of analyzed laminate panels are [0/45]s and [0/30/60]s. The width of the strips is 10 mm, the span of the strips is 20 mm and there is a 20 mm circular notch in the center of the panel right among the strips. The FEA is focused on a comparison of pure glass laminate and FOF laminate with the same plies’ orientation. The results show approximately 20% increase of FOF laminate natural frequencies for [0/45]s layup and about 5 % increase in twisting modes and 13 % increase of natural frequencies in bending modes for [0/30/60]s layup. The experiments focus on verifying the actual values of frequencies and subsequent comparison with numerical values determined by simulation. Experimental results show 1-10 % deviation for [0/45]s layup and 10-16 % deviation for [0/30/60]s layup. These enhancements help to prevent resonance in standard operating frequencies of mechanisms and machines, thus extending their operational lifespan. Additionally, the strategic placement of functional material strips around structural openings provides increased stiffness without the need for extra layers, effectively reducing the laminate's overall mass. This study highlights the potential of FOF to improve the dynamic performance and lifespan of laminated composite structures used in various engineering applications.