Prediction of damage characteristics of apple fruit based on test and finite element method

Abstract

Apples are highly nutritious, however, their thin peel and high crispness make them susceptible to various forms of damage during harvesting, transportation, storage, and grading. Mechanical damage significantly impacts both their edibility and commercial value. Therefore, it is crucial to predict and evaluate potential damage in fruit production and logistics. In this study, the effects of compressive damage on apple fruits were investigated. A multi-scale finite element analysis (FEA) model, incorporating both the peel and flesh, was developed to analyze the impact of compression distance and storage time (1, 3, 5 days) on internal stress variations within the fruit. The results indicate that, when compressed at displacements of 2 mm, 4 mm, and 6 mm, the maximum equivalent stress in the flesh and peel reached 0.31, 0.52, 0.68 MPa, and 0.19, 0.30, 0.49 MPa, respectively. The force-displacement curves from both experimental data and finite element method (FEM) simulations for apples stored over different durations showed high correlation coefficients of 0.9911, 0.9931, and 0.9955, respectively, confirming the model's ability to accurately simulate real compression scenarios. The integration of experimental results with finite element methods provides a more comprehensive understanding of the mechanical properties and damage relationships in apples, offering significant insights for predicting internal damage and developing new systems to prevent fruit damage.