Drag reduction and wear resistance mechanisms of a bionic shovel by discrete element method simulation

Zhang³

et al. 2020

Energies

Self Cite

Four kinds of feet with typical structures, referred to as the hemispherical foot, the semicylindrical foot, the rectangular foot and the circular foot, respectively, were designed and manufactured to study the foot–terrain interaction mechanics for legged robots. Three kinds of quartz sand were selected to study how particle size, shape and compactness affected the physical properties of the substrate and the intrusion performance of mechanical feet. The media with smaller particle sizes had higher bulk densities and lower angles of stability, but no obvious rule was found for particle shapes of quartz sand with different sizes. The intrusion resistive forces and pressures of the hemispherical foot on these three kinds of quartz sand were all less compared with the other three mechanical feet. The particle disturbance areas and motion trends were compared under these four kinds of mechanical feet using discrete element method simulations. The intrusion resistive forces of these mechanical feet first increased and then decreased with the increasing particle sizes of the quartz sand. Moreover, the intrusion resistive forces of these mechanical feet on spherical particles were smaller compared with irregular particles. The corresponding resistive forces of the mechanical feet were characterized based on the compactness of the quartz sand. According to the intrusion test data, the classic pressure–sinkage model was modified, and the relationships between intrusion resistive force and mechanical foot depth were obtained.

Section: Discrete Element Simulation Of Mechanical Feet Intruding Intmentioning

confidence: 98%

Mechanical Performances of Typical Robot Feet Intruding into Sands

Han

Zhang³

et al. 2020

Energies

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“…tip [14]. Correspondingly, due to the abrasive resistance, the element velocity of the scales seems to undergo a nonuniform change.…”

Section: Appl Sci 2020 10 X For Peer Reviewmentioning

confidence: 98%

“…With the pangolin scale moving forward, some particles of abrasive sand are propelled forward, and some others are forced to move up or down due to the resistance of the frontal sand abrasives. The vortex flow of the abrasive sand caused by the moving scale emerges near the scale tip [14]. Correspondingly, due to the abrasive resistance, the element velocity of the scales seems to undergo a nonuniform change.…”

Section: Appl Sci 2020 10 X For Peer Reviewmentioning

confidence: 98%

Analysis of Wear-Resistant Surface with Pangolin Scale Morphology by DEM Simulation

Pang

et al. 2020

Applied Sciences

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Based on the Discrete Element Method (DEM), an abrasive wear system composed of pangolin scale models and abrasive sand was established. The wear morphology of pangolin scale models under different velocities were simulated by PFC2D®. Their wear behaviors were discussed with regard to the contact bond fields, the contact force chains, the velocity fields and the displacement fields of the abrasive wear system. Moreover, the resistance of the pangolin scale models under different velocities were analyzed. In the DEM simulation, the fracture and debris locomotion on the scale model were observed at a meso-microscopic scale. The results show that the geometrical shape of the pangolin scale is helpful for decreasing the boundary stress, with the wear rate decreasing when the velocity is higher than 0.62 m·s−1. The wear rate is no more than 0.006 g/m under the abrasive sand, with a radius of 0.11–0.20 mm. The wear rates of the pangolin scale model agree with the experimental results, and the DEM provides a new way to study the abrasive wear behavior of this non-smooth biological surface.

“…In order to represent the structural forces in the continuum, a clamping device is used to represent the inherent constraints in the material. When the external force is greater than the normal or tangential constraint of the particle, the constraint will be broken [9][10] .…”

Section: Discrete Element Simulation Analysis Of Wearing Behavior Of ...mentioning

confidence: 99%

DEM Simulation in Wear Performance of Four Typical Bionic Structures

Yang²,

Zhao

et al. 2022

J. Phys.: Conf. Ser.

Self Cite

In order to resist the abrasion of sand and gravel, shellfish such as arca subcrenala lischke and arca inflata reeve have evolved non-smooth surface morphology with high wear resistance. In this paper, four biomimetic structures of prismatic, conical, ball crown and stripd were designed to study the abrasive wear behavior of different biomimetic structures. Built on the Discrete Element Method (DEM), the DEM model and its abrasive wear calculation model are established. By analyzing the changes of the contact bond field of the abrasive wear system, the non-uniform evolution process and wear law of the abrasive wear process of the four bionic structures are obtained. The research in this paper provides a new research method and means for the numerical simulation of wear behavior of biomimetic structures and the optimal design of biomimetic structures based on the surface morphology of biological non-smooth wear-resistant bodies.