Perbandingan Ketangguhan Retak Silkworm Fiber Reinforced Composites (FRC) Antara Posisi Neutral dan Compression

Background: Fiber Reinforced Composites (FRC) is composites material combined with fiber which fequently used as fixed denture material since it has good aesthetics, easily attached to teeth and not easily separathed. Fiber on FRC is used as an amplifier and increase the mechanical strength. Fracture thoughness one of the mechanical sthrength that determine the sthrength of FRC. Some of the factors that effect the mechanical strength of fiber are fiber position. Aim: to find out the difference in position of silkworm fiber has an effect on the fracture thoughness of FRC and to find out in neutral side or compression side that has higher fracture thoughness on silkworm fiber reinforced composites. Methods: This study was a pure laboratory experimental. The sampel used was Rectangle with length 25mm, width 2mm, height 2mm, and there are notch in the mid of tension side with depth 0.9mm its amounts 32 which were divided into 2 groups: neutral side and compression side. Fracture thoughness tested with three point bending using Universal Testing Machine. Result: The result showed the difference of the average value on 2 groups of samples.Neutral side (185,111 MPa.m1/2) is higher fracture thoughtness than compression side (132,770 MPa.m1/2).sample t test showed a significant difference of both position that was p=0 (p