Experimental Study on the Mechanical Properties of Friction, Collision and Compression of Tiger Nut Tubers

Abstract

The mechanical properties of agricultural materials can provide the basis for the design and optimisation of agricultural machinery. There are currently very few studies on the mechanical properties of tiger nut tubers, which is not conducive to the design and development of machinery for their harvesting and processing. To obtain the mechanical parameters of tiger nut tubers, this study investigated the effects of variety (Zhong Yousha 1 and Zhong Yousha 2), moisture content (8%, 16%, 24%, 32% and 40%), contact material (steel, aluminium, plexiglass and polyurethane), release height (170 mm, 220 mm, 270 mm and 320 mm), loading speed (5 mm/min, 10 mm/min, 15 mm/min and 20 mm/min), compression direction (vertical and horizontal) on the friction, collision and compression mechanical properties of the tubers. The results were as follows: Both moisture content and contact material had a significant effect (p < 0.01) on the sliding friction coefficient (0.405–0.652) of the tubers; both variety and moisture content had a significant effect (p < 0.01) on the angle of repose (27.96–36.09°); contact material, moisture content, release height and variety all had a significant effect (p < 0.01) on the collision recovery coefficient (0.376–0.672) of tubers; variety, loading speed, moisture content and compression direction all had significant effects (p < 0.01) on the damage force (87.54–214.48 N), deformation (1.25–6.12 mm) and damage energy (82.38–351.08 mJ) of the tubers; only moisture content and compression direction had significant effects (p < 0.01) on the apparent elastic modulus (12.17–120.88 MPa) of the tubers. The results of this study can provide a reference for the design and optimisation of machinery for the harvesting and processing of tiger nut tubers.

Effect of Moisture Content on Frictional Properties of Some Selected Grains in Indonesia

“…The same phenomenon could also be observed where the values of θ increased with moisture contents. The same phenomenon was also reported by other researchers (Dauda et al, 2019;Inekwe, 2019;Jan et al, 2019;Larsson, 2019;Mohite et al, 2019;Etim et al, 2021;Kopeć-Jarosz & Wójcik, 2021;Wang et al, 2022;Zhang et al, 2022). As can be observed, all the linear regression lines of the grains showed positive increments but differed in steepness, indicating that θ of the tested grains increased with moisture content.…”

“…The opposite condition occurred in rough rice, as there was a husk layer on the grain. The sliding friction coefficient of tiger nut on steel, aluminum, plexiglass, and polyurethane was reported to have a linear increase in moisture content (Zhang et al, 2022). The same phenomenon was reported for mucuna beans on plywood, aluminum, glass, galvanized steel, and rough wood (Etim et al, 2021).…”

Design and Test of a Crawler-Type Tiger-Nut Combine Harvester

“…The contact parameters between tiger-nut tubers and steel plates and those between tiger-nut tubers were obtained by calibration [30,31]. Other parameters were determined by referring to published literature [32][33][34]. On the basis of research by the research group, the contact parameters and mechanical of the selected materials are shown in Tables 4 and 5.…”

Compressive mechanical properties of cottonseed

“…These studies can be conducted using the experimental methods of other plant seeds for reference. Many scholars studied the compression characteristics of hazelnut (Cristiana et al, 2015), sorghum grain (Feng et al, 2022), naked oat seed (Zhang et al, 2019;Qiu et al, 2021), almond (Shi et al, 2021), millet (Yang et al, 2015;Sun et al, 2017), and other seeds. The results showed that moisture content, compression direction, and variety affect the destructive force, deformation, and destructive energy of grains.…”