Kołodziej Paweł, Stropek Zbigniew, Gołacki Krzysztof
Department of Mechanical Engineering and Automation, Faculty of Production Engineering, University of Life Sciences in Lublin, 20-612 Lublin, Poland.
Materials (Basel). 2023 Feb 2;16(3):1281. doi: 10.3390/ma16031281.
Root damages due to mechanical impacts result in deterioration in commercial sugar beet quality. In order to determine the mechanical characteristics of roots, a stand equipped with a pendulum enabling impact investigations of whole beets was used. The roots were stored in a monitored environment for up to 5 days (temperature 15 ± 2 °C, 40 ± 2%). During the tests, the beets were struck against a flat steel resistant surface with the velocities = 0.5, 1.0 and 1.5 m·s. The measurements of local root curvatures in three chosen impact areas and the deformation () allowed modelling of the volume of contact () by means of the ellipsoid cap. These investigations enabled the determination of the relations between the maximal impact force, , the impact energy, , and the absorbed energy, , as well as the contact volume and impact velocity, taking into account the root storage time, . It was found that the maximal impact force increased with increasing impact velocity and decreased with the storage time for each group of roots. With increasing velocity, there were also increases in the following: impact energy, absorbed energy, contact volume and maximal deformation, as well as absorbed energy, referred to as the mass from . The mean values of the stresses (), being the quotients of the impact force () and the surface area of the ellipsoid cap base (), were 0.81-1.17 MPa, 1.064-1.59 MPa and 1.45-1.77 MPa for the velocities of 0.5, 1.0 and 1.5 m·s, respectively. It was confirmed that the statistical significance of the mentioned parameters changes depending on the impact velocity.
机械冲击造成的根部损伤会导致商业甜菜品质下降。为了确定根部的机械特性，使用了一个配备摆锤的试验台，以便对整个甜菜进行冲击研究。根部在监测环境中储存长达5天（温度15±2°C，湿度40±2%）。在测试过程中，甜菜以0.5、1.0和1.5 m·s的速度撞击平坦的抗钢表面。对三个选定冲击区域的局部根部曲率和变形（）进行测量，从而通过椭球帽对接触体积（）进行建模。这些研究能够确定最大冲击力、、冲击能量、和吸收能量、之间的关系，以及接触体积和冲击速度之间的关系，同时考虑根部储存时间。研究发现，每组根部的最大冲击力随冲击速度的增加而增大，随储存时间的延长而减小。随着速度的增加，以下各项也会增加：冲击能量、吸收能量、接触体积和最大变形，以及吸收能量，即从得到的质量。应力（）的平均值，即冲击力（）与椭球帽底部表面积（）的商，对于0.5、1.0和1.5 m·s的速度分别为0.81 - 1.17 MPa、1.064 - 1.59 MPa和1.45 - 1.77 MPa。已证实上述参数的统计显著性会因冲击速度而异。
