Karakteristik laju perambatan retak fatik bahan komposit berpenguat serat kenaf dengan matrik polyester

Oleh :
Hafis Syafrudin Anshari - I1405005 - Fak. Teknik

Intisari Aplikasi komposit serat alam di bidang otomotif berkembang sangat pesat. Sebagai contoh, komposit serat kenaf telah digunakan oleh Toyota untuk panel-panel interior pada mobil kelas premium. Sesungguhnya, panel-panel itu menerima beban dinamis dan kegagalannya dapat disebabkan oleh fatik. Material utama yang digunakan adalah serat kenaf (acak, kontinyu, anyam) unsaturated polyester, methyl ethyl keton peroxide (MEKPO). Komposit dibuat dengan metode cetak tekan untuk fraksi volume serat 40%. Laminat divariasi untuk serat acak, anyam, kontinyu, acak-anyam-acak, dan kontinyu-anyam-kontinyu. Pengujian fatik dilakukan pada stress rasio (R) = 0. Persamaan perambatan retak komposit yang diperkuat serat acak, anyam, acak-anyam-acak, dan kontinyu-anyam-kontinyu secara berurutan adalah da/dN = 8.10-14(ΔK)4,810, da/dN = 7.10-15(ΔK)4,918, da/dN=1.10-14(ΔK)5,500 dan da/dN = 7.10-9(ΔK)2,254. ABSTRACT Natural fiber composite materials have been applied in automotive. For example, kenaf fiber composite have been used by Toyota for interior panels as premium car class. Certainly, the panels receive dynamic load and its failure can be caused by fatigue. The main materials used were kenaf fibers (random, continue and woven), unsaturated polyester and methyl ethyl keton peroxide (MEKPO) hardener. The composite was produced by using a press mold method for about 40% of fiber volume fraction. The laminates was varied for random, woven, continue and random-woven-random and continue-woven-continue fibers. For fatigue test, the specimens were loaded by tension fatigue load for stress ratio (R) = 0. The equation of fatigue crack growth on composite reinforced by random, woven, random-woven-random and continue-woven-continue fibers were continuous sequence respectively da/dN = 8.10-14(ΔK)4,810, da/dN = 7.10-15(ΔK)4,918, da/dN=1.10-14(ΔK)5,500 dan da/dN = 7.10-9(ΔK)2,254.