Abstract:

The investigation of the crack propagation behaviour associating with the delamination in the interface of the laminate of the fibre acrylic laminates (FALs) composite is carried out by subjecting the composite to cyclic loads. The cyclic load is controlled by the displacement provided by a fatigue testing machine. The cyclic load was carried out with various displacement ratios, R, values, these are, 0, –1, –3, and –5 in which the displacement amplitude was also varied as high as 0.15, 0.20, 0.30 mm, for every value of R. In the present study, the investigation to the crack propagation behaviour is focused on the negative cyclic of R leading to the composite to be cycled under compressive load. The results obtained in the present study shows that in these cases of the lower value of the displacement ratio of –3 and –5, the fatigue life and the crack length of the FALs increase, and the increasing of the displacement amplitude to 0.30 mm causes both the fatigue life and the crack length to be shorter. The delamination propagation rate is higher in the R=0 case than those in the negative value of R. In addition, the lateral contraction of material to outward over the crack region may contribute to the development of the delamination when the ratio of the displacement cycles is negative, and the lateral contraction is higher when the displacement ratio is more negative. Moreover, the delamination may take place in front of the crack tip when the maximum displacement is 0.20 mm or higher, and it causes the crack propagation to be accelerated Author Biographies Anindito Purnowidodo, Brawijaya University Malang Jalan. Mayjend Haryono, 167, Malang, Indonesia, 65145 Doctor of Technical Sciences, Associate Professor Department of Mechanical Engineering

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