Radial compression response of honeycomb rollers with multi dense degrees for forest harvester

  Objective   The radial compression response of honeycomb rollers with multi dense degrees for forest harvester was studied under simulated working conditions, that is, clamping and overturning process during logging.

  Method  15 kinds of rollers were divided into three grades according to different dense degrees. In order to obtain the quantitative exploration of mechanical and energy absorption characteristics, a combined theoretical and numerical study was designed. Then 3 of them was selected for manufacturing, and radial compression tests in linear elasticity phase were carried out. After monitoring with digital image correlation technology, the node deformation at the plastic hinge was compared. By comparing the results of simulation and test, the deformation mode of roller of double V-wing honeycomb (RDVH) with multi dense degrees was studied.

  Result  The simulation results in the platform stage showed that, with the increase of dense degree by about 10%, the increase of equivalent stress of honeycomb roll was within 2 MPa, but the energy absorption increased by nearly 6 times. The test results in the linear elastic stage showed that the same increase in dense degree acted as a trigger for a mass increase of 59.78%, while it had largely led to the promotion of contact force to about 3.4 times. The V mode deformation pattern was proposed in this work, which could be verified when the dispersion coefficient was less than 6%.

  Conclusion  The compression response of RDVH with dense degrees in the range of 25%−40% could be shown as follows: to begin with, the dense degree, which is significantly induced by wall thickness and number of layers, has a remarkable nonlinear positive correlation with equivalent stress and energy absorption. Furthermore, under approximate dense degrees, the increase of wall thickness could be capable to meet higher compressive strength, while the decrease of the number of layers would contribute to the improvement of energy absorption. Finally, the deformation mechanism of RDVH in circumferential directions shows uneven auxeticity.