Physical property of watermelon. Compressive characteristics of flesh of watermelon at static loading
More details
Hide details
Faculty of Agriculture, Kobe University, Rokkodai-cho 1-1, Nada-ku, Kobe 657, Japan
Publication date: 2021-08-19
Int. Agrophys. 1994, 8(3): 415–419
It is difficult to measure the physical properties of agricultural products precisely. In this study, two displacements of the axial and the radial directions of cylindrical specimens of the flesh of watermelon were measured with non-contact displacement sensors at static loading. The two displacement sensors are of the optical-reflective type with a light emitting diode and a semiconductor laser diode. The outputs are analogue voltages in proportion to each displacement measured in units of 1 µrn. The approximate dimensions of the specimens were 40 mm in diameter and 34mm in height, and the actual dimensions were measured automatically by the experimental device. The experiments were done by setting the axis of the cylindrical specimens vertically and by altering the static load on the specimens at 0.0098 N (equal to the stress about 7.8 Pa ), 0.0196 N (15.6 Pa ), 0.049 N (39 Pa), 0.098 N (78 Pa), 0.196 N (156 Pa), 0.490 N (390 Pa), 0.98 N (780 Pa) and 1.18 N (936 Pa) as the distributed loads, and 0.490 N, 0.98 N and 1.18 N as the concentrated loads. The results show that the two displacements are generated by the static-distributed load, and that the displacements return to the original condition when the load is in the range of under about 0.05 N and when it is removed. When the load value increases, the permanent strain remains.