V. G. Zhukov, N. S. Lukina, E. N. Maleeva
All-Russian Research Institute of Starch Products – the branch of the V. M. Gorbatov Federal Science Center of Food Systems of the RAS, ul. Nekrasova, 11, pos. Kraskovo, Lyuberetskii r-n, Moskovskaya obl., 140051, Russian Federation
Abstract. Mechanical characteristics of potato pulp are most often studied, using a technique of uniaxial compression of cylindrical samples, cut out from tubers. As a result, charts were obtained in the coordinates of the tension – relative deformation. Depending on experimental conditions, the charts can be rectilinear, have an S-shaped form or other appearance. The aim of the research was to study the influence of a ratio of the sample length to its diameter and conditions of samples fastening in supports on the chart shape. The experiments were carried out by a laboratory unit with a mechanical drive for examination of weak materials in samples having various ratios of length to a diameter within the range of 0.357–1.786. The samples were divided into two groups. One group of samples was put between simple rigid flat and smooth metal supports. To identify the impact of the support roughness on the chart, the samples of the other group was put in supports, which were covered by a 4-mm gasket with a thin emery covering. A check of the dependence of gasket deformation from longitudinal loading revealed the linear relation and, consequently, their deformation could not influence chart curvilinearity in experiments. All samples showed axial compression charts with S-shaped curves regardless of the length and conditions of fastening in supports. In each group there was a tendency according to which with decreasing sample length its relative deformation increases. The main reason for steadily larger relative deformations in short samples compared with the longer ones is a small dominator for these samples. It is suggested also that this fact is affected by the edge effect from supports.
Keywords: potato tuber; cylindrical sample; axial compression; S-shaped chart; tension; deformation.
Author Details: V. G. Zhukov, D. Sc. (Tech.), chief research fellow (е-mail: Этот адрес электронной почты защищён от спам-ботов. У вас должен быть включен JavaScript для просмотра.); N. S. Lukina, senior research fellow; E. N. Maleeva, senior research fellow.
For citation: Zhukov V. G., Lukina N. S., Maleeva E. N. Shape of a Compression Chart of Cylindrical Samples of Various Length from Potato Tubers. Dostizheniya nauki i tekhniki APK. 2018. Vol. 32. No. 10. Pp. 87–89 (in Russ.). DOI: 10.24411/0235-2451-2018-11020.