Kruszelnicka Weronika
Department of Machines and Technical Systems, Faculty of Mechanical Engineering, University of Science and Technology in Bydgoszcz, 85-796 Bydgoszcz, Poland.
Materials (Basel). 2021 Mar 17;14(6):1467. doi: 10.3390/ma14061467.
Mechanical properties of corn grains are of key importance in a design of processing machines whose energy demand depends on these properties. The aim of this study is to determine the selected mechanical properties of corn grains and the rupture energy. The research problem was formulated as questions: (1) How much force and energy is needed to induce a rupture of corn grain maintaining good quality of the product of processing (mixing, grinding transport)? (2) Can empirical distributions of the studied physical-mechanical properties be described by means of probability distributions provided by the literature? (3) Is there a relationship between the corn grain size and the selected mechanical properties, as well as rupture energy? In order to achieve the goals, the selected physical properties (size, volume) of corn grains have been distinguished and a static compression test has been carried out on an Instron 5966 testing machine. The results indicate a significant scatter of the results in terms of size, grain shape, forces, energy, and deformation corresponding to the point of inflection, bioyiled point, and rupture point. It has also been indicated that empirical distributions of the analyzed properties can be described by means of distributions known from the literature, e.g., gamma, Weibull or lognormal distributions. It has been confirmed that mechanical properties such as force, energy, and stress that cause rupture depend on the grain size, more precisely, the grain thickness-there are negative relations between thickness and force, energy and stress in relation to the point of inflection, bioyiled point, and rupture point.
玉米粒的机械性能对于加工机器的设计至关重要，这些机器的能源需求取决于这些性能。本研究的目的是确定玉米粒的选定机械性能和破裂能量。研究问题被表述为以下几个问题：（1）在保持加工产品（混合、研磨、运输）质量良好的情况下，使玉米粒破裂需要多大的力和能量？（2）所研究的物理机械性能的经验分布能否用文献中提供的概率分布来描述？（3）玉米粒大小与选定的机械性能以及破裂能量之间是否存在关系？为了实现这些目标，区分了玉米粒的选定物理性能（尺寸、体积），并在Instron 5966试验机上进行了静态压缩试验。结果表明，在尺寸、颗粒形状、力、能量以及对应于拐点、生物屈服点和破裂点的变形方面，结果存在显著分散。还表明，所分析性能的经验分布可以用文献中已知的分布来描述，例如伽马分布、威布尔分布或对数正态分布。已经证实，导致破裂的力、能量和应力等机械性能取决于颗粒大小，更确切地说，取决于颗粒厚度——在厚度与相对于拐点、生物屈服点和破裂点的力、能量和应力之间存在负相关关系。
