Analisis Lentur Pada Komposit Serat Rumput Payung (Cyperus Alternifolius) Matriks Epoxy Di Bawah Kondisi Deformasi Layan

Abstract

The rapid development of material technology has accelerated the use of natural fibers in composite fabrication. The application of natural fiber composites in industry and construction has increased because natural fibers offer several advantages, such as sustainability, lightweight properties, and good mechanical performance. One factor affecting the strength of natural fiber composites is fiber length, which influences mechanical properties and fiber performance in composite applications. This study conducted a flexural analysis of umbrella grass (Cyperus alternifolius) fiber composite with epoxy matrix under service deformation conditions using three fiber length variations: 3 mm, 6 mm, and 9 mm. A total of four specimens were prepared for each variation for flexural testing. The specimen dimensions and setup followed ASTM D7264/D7264M-07, with a length of 153.6 mm, width of 13 mm, and thickness of 4 mm. During testing, a 10 mm deflection limit was used to determine the maximum flexural stress occurring in each specimen. The flexural performance analyzed included specimen shape before and after testing, maximum flexural load, and maximum flexural stress in relation to fiber length. The test results showed that more uniform fiber deformation could affect the maximum load response. This condition made the maximum load reading less optimal. In addition, the fiber composite exhibited elastic behavior, so a deflection of 10 mm was used as the reference point for maximum load. The maximum loads for 3 mm, 6 mm, and 9 mm fiber lengths were 9.53 N, 3.45 N, and 10.34 N, respectively. In specimen B, nonuniform fiber deformation occurred at the midspan, resulting in lower load and stress values. The maximum load showed an increasing trend as fiber length increased. The maximum flexural stress values for fiber lengths of 3 mm, 6 mm, and 9 mm were 8.80 N/mm², 3.19 N/mm², and 9.54 N/mm², respectively. Likewise, flexural stress also showed an increasing trend with increasing fiber length