ABSTRAKRekayasa struktur honeycomb sandwich dalam pengembangan material banyak telah dimanfaatkan karena memiliki kekuatan struktur yang relatif tinggi dengan bobot material yang ringan. Material dengan rekayasa struktur honeycomb cocok digunakan pada mobil hemat energi, untuk meningkatkan efesiensi energi. Dalam penelitian ini dibuat panel honeycomb sandwich berbahan komposit serat kaca (fibreglass) dan matirks resin. Panel ini nantinya akan diterapkan pada rangka kendaraan hemat energi. Tiga panel honeycomb sandwich dibuat dengan variasi pada ketebalan dinding sel terutama ditujukan untuk mengetahui pengaruh ketebalan dinding sel terhadap kekuatan dan kekakuan panel honeycomb sandwich. Variasi ketebalan dinding sel didapatkan dari variasi penerapan jumlah lapisan fiberglass pada dinding sel honeycomb, yaitu 2 lapis, 4 lapis dan 6 lapis fibreglass. Hasil pengujian bending menunjukkan bahwa panel honeycomb sandwich dengan ketebalan dinding sel terbesar, yaitu dengan 6 lapisan fibreglass, memberikan kekuatan lentur terbesar yaitu 3,774 kg/mm2, dan kekakuan tertinggi, yaitu 21,48 kg/mm.Kata kunci: honeycomb sandwich, komposit fibreglass, kekuatan lentur, kekakuan.  ABSTRACTEngineering of honeycomb sandwich structure in the materials development has been highly utilized because of its high structural strength with lightweight material. Honeycomb structure material is suitable for use in energy-efficient cars, to increase energy efficiency. In this research, sandwich honeycomb panel were made from fibreglass composite with resin as matrices. This panel will be applied to the frame of energy-efficient vehicle. Three sandwich honeycomb panels were made with variations in cell wall thickness. These variations are primarily intended to determine the effect of cell wall thickness to the flexural strength and stiffness of the honeycomb sandwich panel. Variations in cell wall thickness were obtained from variations in the application of fibreglass layers on honeycomb cell walls, which are 2 layers, 4 layers and 6 layers of fibreglass. The bending test results show that the honeycomb sandwich panel with the largest cell wall thickness, which has 6 layers of fibreglass, provides the greatest flexural strength of 3.774 kg/mm2, and the highest stiffness of 21.48 kg/mm.Keywords: honeycomb sandwich,fibreglass composite , flexurall strength, stiffness.