Research Of Mechanical Characteristics Of Feeding Roller Of Forest Combine Harvester Based On Flexible Honeycomb Structure

Aiming at the problem of serious damage of the logs caused by the small contact area between the feeding roller and logs,during the operation process of forest combine harvester.A new type of feeding roller based on the flexible honeycomb structure with V-winged was proposed to change the stiffness of the feeding roller,improve its elasticity in the vertical direction and increase the effective contact area between the feeding roller and the log,thereby reducing the damage to the log.According to the structural parameters of the feeding roller,the cell of flexible honeycomb structure and the structural form of feeding roller were designed,By analyzing the stress condition of honeycomb structure in the cutting operation,the mechanical stress and deformation of the long wall and the short wall of the cell was discussed respectively.Based on the displacement method,a theoretical model of in-plane elastic constant was established to evaluate the mechanical properties of the cell.The solid models with different structural parameters wrere constructed,the cell experimental components of the structure were prepared.the effects of thickness t?lower angle?₁?upper angle?₂ and cell half-width L on the in-plane elastic constants of the structure were studied by finite element simulation and experiment,and the correctness of the theoretical model was verified.The results show that E_y,the y-direction equivalent modulus of elasticity about the flexible honeycomb structure,increases with the cell thickness of honeycomb walls,and decreases with the lower angle and half width of honeycomb,and the upper angle has less influence on it.E_x,the x-direction equivalent modulus of elasticity about the flexible honeycomb structure,increases with the lower angle?upper angle and cell thickness of honeycomb walls,and decreases with the half width of honeycomb,While,the Poisson's ratio?_xy and?_yx are only affected by lower angle and upper angle,but the same parameter has opposite effect on?_xy and?_yx.By setting the actual working condition of feeding roller during cutting operation,The dynamic compression process of the whole flexible honeycomb structure under the impact load was simulated by ANSYS LS-DYNA.By analyzing the characteristics of the structure in the three stages of compression,it was concluded that the structure can effectively increase the contact surface between the feeding roller and the logs and reduce the damage to the logs when it is applied to the feeding roller in the elastic range of 10%-30%compression.And the maximum displacement of the flexible honeycomb structure in z-direction caused by the working load is within the acceptable range,the strength of the structure in z-direction meets the requirements of logging conditions.The theoretical model can approximately represent the in-plane mechanical properties of the structure,which has certain guiding significance for the selection of parameters when the feeding roller adopts the flexible honeycomb structure with V-winged.