Current Issue : January-March Volume : 2023 Issue Number : 1 Articles : 5 Articles
In order to increase the structural performance of rotary tillage knife, a badger claw toe was selected as the bionic prototype of the rotary tillage knife, and the bionic optimization design of the rotary tillage knife was carried out. The structural similarity between the badger’s claw toe and the rotary tiller is 0.7073 by the fuzzy algorithm, and the shape goodness of fit between the final mole’s claw toe and the digging shovel is 0.9556 by MATLAB. Using 3D modeling software NX10.0, we established a three-dimensional model of the rotary tillage knife. Furthermore, we use Workbench to carry out static analysis on the three rotary tillage knives and obtain their stress and deformation. Similarly, we also obtain their vibration frequency through modal analysis, summarize, and compare the experimental data.The outcomes indicate that compared with the ordinary rotary tillage knife, the strain and stress of the bionic rotary tillage knife with sawtooth tangent blade arrangement are reduced by 5.20% and 2.84%, respectively. Moreover, the specific strength and specific stiffness are increased by 3.99% and 6.49%, respectively. The structural efficiency is improved by 11.36%. However, the stress of the bionic rotary tiller with full serration is reduced by 7.38%. We also observed that the specific strength and specific stiffness were improved by 11.97% and 2.37%, correspondingly. Overall, structural efficiency has increased by 14.64%. The rotary tiller has also attained noble optimization outcomes in terms of stability, strength, and stiffness....
The toughening mechanism of the nacre was widely investigated in recent decades, which presents a great prospect for designing high performance composite materials and engineering structures with bioinspired structures. To further elucidate which structural parameters and which kinds of morphology of the nacre-inspired structure are the best for improving tensile strength without sacrificing too much toughness is extremely significant for composite materials and engineering structures. The “brick-and-mortar” structure is a classical nacre-inspired bionic structure. Three characteristic structural parameters, including the aspect ratio ρ of the brick length and width, the thickness ratio β between the thickness of brick and mortar, and the spacing ratio τ between the width of brick and mortar, were used as variables to study their effect on tensile strength and toughness. It was found that ρ was the most prominent factor in determining the strength and toughness, and τ could improve the strength and toughness almost simultaneously. Racked and wedged morphology of the structural unit were established based on the structural parameters of the regular staggered unit, and were used to compare tensile behavior. It was found that the model with the wedged unit possessed the highest strength and toughness, and could absorb more strain energy during fracture crack growing. The crack propagation path further illustrated that the crack resisting ability of the wedged unit was the best. Our simulation results presented the connection between three characteristic structural parameters with the strength and toughness, and proved that the wedged staggered unit was the best in improving the strength and toughness....
Heavy metal soil remediation is an important component in mitigating environmental problems, and microbial remediation has good treatment effect, good environmental affinity, and high treatment cost treatment efficiency. Numerical simulations of soil remediation effects enable the selection of suitable remediation methods and the determination of the optimal remediation input ratio. However, the current numerical simulation mainly relies on a single mathematical model, and the simulation error is large when applied to the microbial remediation with large variability. Numerical simulation methods of microbial remediation impacts of heavy metal contaminated soils will be investigated to overcome the foregoing problems. By researching the migratory law of heavy metal contaminated soil components, the process of microbial remediation of heavy metal contaminated soil will be examined, and a microbial proliferation model will be constructed. The numerical simulation of microbial remediation effect is realized by using HYDRUS to inverse solve the data of small laboratory tests and obtain the relevant parameters for numerical simulation. The maximum simulation error of the method studied at the time of testing was 2.1%, the simulation trend was consistent with the real remediation effect, and the simulation results were reliable. Although the simulation results of the numerical simulation method of the microbial remediation effect of heavy metal polluted soil proposed in this paper differ from actual values of the microbial remediation of heavy metals in soil, the overall trend of changes in soil heavy metal content is similar. It reveals that the outcomes of the approach investigated in this work are somewhat trustworthy when numerically modeling the effect of microbial remediation of heavy metals in soils. In other words, the numerical modeling approach utilized in this work to examine the impact of microbial remediation of heavy metalcontaminated soil is highly precise and effective....
Aiming at the problems that tomatoes are fragile and the traditional end-effector design is not suitable for tomato picking, a combination of the bionic principle of FRE structure and finger design was proposed. Based on the physical properties of tomatoes, a flexible underactuated end-effector for tomato picking and sorting was designed. The optimal structural parameters of fingers were determined by finite element analysis, and the tomato grasping experiment was carried out. The results show that the flexible end can grasp and transport tomatoes with diameters ranging from 65 to 95mm without damage, which can withstand 7N tensile force, the load is more than 2 times of its own weight, the tomato coverage rate is greater than 23.6%, and the effective grab rate is 100% and has the advantages of the strong stability, universality, and protection. The research provides a novel solution for the design and application of the tomato picking and sorting robot end-effector....
In nature, live fish has various deformable fins which are capable to promote the swimming speed, efficiency, stability, and thrust generation. However, this feature is rarely possessed by current man-made biomimetic robotic fishes. In this paper, a novel deformable caudal fin platform is proposed to improve thrust generation of biomimetic robotic fish. First, the design of the deformable caudal fin is given, which includes a servo motor, a gear-based transmission mechanism, fin bones, and silica membrane. Second, an improved Central Pattern Generator (CPG) model was developed to coordinately control the flapping of the tail and the deformation of the caudal fin. More specifically, three deformation patterns, i.e., conventional nondeformable mode, sinusoidal-based mode, instant mode, of the caudal fin are investigated. Third, extensive experiments are conducted to explore the effects of deformation of the caudal fin on the thrust generation of the biomimetic robotic fish. It was found that the instant mode of the caudal fin has the largest thrust, which sees a 27.5% improvement compared to the conventional nondeformable mode, followed by the sinusoidal-based mode, which also sees an 18.2% improvement. This work provides a novel way to design and control the deformation of the caudal fin, which sheds light on the development of high-performance biomimetic robotic fish....
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