Finite element simulation of mechanical properties of Rosa roxburghii under compression loading

Macroscopic and microscopic investigations of determining elasto-mechanical properties of limequat fruit

Given the paramount importance of agricultural products in global health and food security, and the increasing consumer demand, understanding the mechanical behavior of these materials under various conditions is necessary yet challenging. Due to their heterogeneous and non-uniform nature, determining their mechanical behavior is complex. This study employs atomic force microscopy (AFM) to determine the modulus of elasticity of limequat fruit at the microscopic scale and compares it with macroscopic methods. The analyses revealed a statistically significant difference (at the 1% level) in the mechanical behavior determined at the macroscopic scale. The highest modulus of elasticity, 0.752 MPa, was observed using Hertz's theory under complete placement between two parallel planes. The lowest, 0.059 MPa, was noted when a spherical probe compressed a rectangular sample. The average modulus of elasticity of the limequat peel was 2.007 MPa. At the microscopic scale, the modulus of elasticity of the fruit tissue ranged from 0.370 to 0.365 MPa, and for the peel, it was 0.246 MPa. RESEARCH HIGHLIGHTS: Working principles of this innovative technique were elaborated. The AFM technique used provide elasto-mechanical properties determination of cell walls of single living cells extracted from biological materials on the nanoscale. By combining AFM topographical image and nano-indentation of living fruit cells it will be possible to investigate cells' elasto-mechanical properties. Atomic force microscopy holds great potential for monitoring fruit mechanical properties of biological materials.

Study of the mechanical compression properties of Rosa sterilis S.D. Shi based on FEM

Understanding the mechanical properties of Rosa sterilis S.D. Shi is important for the design and improvement of related mechanical equipment for planting, picking, processing, and transporting Rosa sterilis S.D. Shi. Compression damage is a common form of mechanical damage in agricultural products, especially during automated mechanical production. Therefore, this study establishes a three-dimensional model of seedless prickly pear fruit based on image processing technology and analyzes the compressive mechanical properties of seedless prickly pear under different directions through experiments combined with finite element method simulation. In both simulation and actual results, the average correlation coefficients were found to be 0.99 and 0.98 for the vertical compression direction and the horizontal compression direction, respectively. The above results show that our finite element compression model can provide a comprehensive understanding of the mechanical properties of Rosa sterilis S.D. Shi fruits under different directional loads. There is significant directional sensitivity in the compression resistance of Rosa sterilis S.D. Shi fruits have horizontal compression resistance greater than vertical compression resistance. The results of this study are of great significance for the development of mechanized automation in the Rosa sterilis S.D. Shi industry and for ensuring the quality of Rosa sterilis S.D. Shi fruits.

Image processing based modeling for Rosa roxburghii fruits mass and volume estimation

The mass and volume of Rosa roxburghii fruits are essential for fruit grading and consumer selection. Physical characteristics such as dimension, projected area, mass, and volume are interrelated. Image-based mass and volume estimation facilitates the automation of fruit grading, which can replace time-consuming and laborious manual grading. In this study, image processing techniques were used to extract fruit dimensions and projected areas, and univariate (linear, quadratic, exponential, and power) and multivariate regression models were used to estimate the mass and volume of Rosa roxburghii fruits. The results showed that the quadratic model based on the criterion projected area (CPA) estimated the best mass (R2 = 0.981) with an accuracy of 99.27%, and the equation is M = 0.280 + 0.940CPA + 0.071CPA2. The multivariate regression model based on three projected areas (PA1, PA2, and PA3) estimated the best volume (R2 = 0.898) with an accuracy of 98.24%, and the equation is V = - 8.467 + 0.657PA1 + 1.294PA2 + 0.628PA3. In practical applications, cost savings can be realized by having only one camera position. Therefore, when the required accuracy is low, estimating mass and volume simultaneously from only the dimensional information of the side view or the projected area information of the top view is recommended.

Multiscale Static Compressive Damage Characteristics of Kiwifruit Based on the Finite Element Method

In the handling or processing process, fruits are easily crushed by external loads. This type of damage in fruit often leads to the internal pulp browning and rotting, with the severity largely dependent on the fruit tissue's geometric and mechanical properties. In kiwifruits, with their thin skin and dark-colored flesh, it is particularly challenging to observe and analyze the damage caused by extrusion through traditional experimental methods. The objective of this research is to construct a multi-scale finite element model encompassing the skin, flesh, and core by measuring the geometric and mechanical properties of kiwifruit, to assess and predict the damage characteristics under compression, and to verify the accuracy of the finite element model through experiments. The results indicated that kiwifruits demonstrated different compressive strengths in different directions during compression. The compressive strength in the axial direction was higher than that in the radial direction, and there was little difference between the long and short radial directions. The flesh tissue is the most vulnerable to mechanical damage under external compression, followed by the core. At strain levels below 5%, there was no noticeable damage in the axial or radial directions of the kiwifruit. However, when strain exceeded 5%, damage began to manifest in some of the flesh tissue. To maintain fruit quality during storage and transportation, the stacking height should not exceed 77 fruits in the axial direction, 48 in the long direction, and 53 in the short direction. The finite element analysis showed that the established model can effectively simulate and predict the internal damage behavior of kiwifruits under compression loads, which is helpful for a deeper understanding of the mechanical properties of fruits and provides a theoretical basis and technical guidance for minimizing mechanical damage during fruit handling.