Biomechanical modeling and numerical analysis of strain-rate-dependent constitutive equations for sugarcane cutting

Sugarcane is a versatile crop used in food, energy, and industry. Improper harvesting can damage the cut surface, affecting regrowth. Sugarcane’s shear strength increases with strain rate during cutting, making a constitutive equation that considers this effect important. This study tested sugarcane epidermis under different strain rates using a universal material testing machine and conducted shear tests on stalks. Abaqus CAE simulations verified that sugarcane epidermis can be treated as an isotropic material. Using the Mises yield criterion and differential-domain variational method, key fracture parameters were determined, and a constitutive equation was built based on the Johnson-Cook model. Comparisons of model calculations, simulations, and physical tests showed the model accurately predicts maximum shear stress, with average errors of 4.273 % (experiments vs. simulations), 4.6435 % (simulations vs. model), and 5.5731 % (experiments vs. model), and a maximum error of 6.925 %. The model effectively describes sugarcane deformation at different cutting speeds, supporting numerical simulations and guiding the design of sugarcane harvester blades. • A Johnson-Cook based constitutive model was developed to describe the strain-rate-dependent mechanical behavior of sugarcane. • A Johnson-Cook model was developed to characterize the strain-rate-dependent mechanical response of sugarcane. • This biomechanical model provides a theoretical basis for numerical simulations and guides the design of sugarcane harvester blades. • The study confirmed that sugarcane epidermis can be treated as an isotropic material, simplifying the modeling process.