Abstract: This article delves into the application of bionic design methodology in enhancing the performance of bucket teeth in excavators. By taking inspiration from the claw toes of the Oriental Mole Cricket, a bionic model for the bucket teeth of the R108-9 excavator is developed. Through simulation analysis, the mechanical properties and deformation patterns of the bionic bucket teeth are studied. The results indicate significant improvements in stress distribution, stiffness, and deformation resistance, ultimately enhancing the excavation performance of the equipment. Keywords: mechanical design, bucket teeth, bionic design, simulation analysis.
1. Introduction
Bionics, as an emerging discipline, encompasses the entire biological world and integrates multiple disciplinary systems such as mechanics, biology, materials science, and electronic information science. It organically connects profound physical principles with the organic life world, aiming to imitate or replicate the body structures and functions of organisms that adapt to the real world and endure environmental changes. By applying engineering principles, bionics guides engineering practice, aiming to improve existing technological engineering equipment and create new technological methods and structural devices.
In recent years, mechanical engineering design has achieved significant advancements through the application of bionic principles. Systematic research has been conducted in mechanical functional structures, mechanical motion mechanisms, mechanical materials, and mechanical control, yielding numerous innovative results and deriving many products based on structural bionics. For example, combining bionic principles and laser additive manufacturing methods has optimized mechanical components in the aerospace field to improve wing stiffness and strength. Imitating the lightweight and high-strength characteristics of bird bones, lightweight composite structural materials have been designed for mechanical equipment, applied to mechanical structural arms and crane arms.
Based on the widespread application and huge potential of bionics in the field of mechanical design, the study of bionic principles and biomechanical principles in mechanical design has increasingly garnered attention. This article combines engineering machinery design, using the claw toes of the Oriental Mole Cricket as a reference, to conduct bionic mechanical property calculations and analyses on the bucket teeth of the R108-9 excavator, studying its mechanical properties and deformation patterns. The research findings can be applied to the performance optimization and equipment retrofitting of existing excavator boom arms and bucket teeth.
2. Theoretical Analysis of Mechanical Structure Bionics
Bionic theory involves the cross-integration of multiple disciplines, encompassing the basic theories of biology, physics, mechanical engineering, and materials science. It is both scientifically profound and practically useful. When applied in the field of mechanical engineering, the bionic theories involved primarily include biological theory, similarity theory, and system and optimization theory.
2.1 Biological Theory
In biological theory, mechanical structure design is based on biological experiments, utilizing principles such as bio-structural self-adaptation, the minimum energy consumption hypothesis, and biological evolution theory to extract biophysical and mechanical characteristics, adapting to more complex mechanical working environments. Compared to metallic materials in mechanical structures, the strength of biological structures, whether at the macroscopic or microscopic scale, is relatively low. However, they can withstand significant loads over a long period, possessing strong toughness and self-repair functions. Additionally, the materials, movement forms, body structures, and energy exchange methods of biological structures conform to the principle of minimum energy consumption, demonstrating divergence and convergence in historical evolution to highly adapt to the environment.
Table 1: Comparison of Mechanical and Biological Structural Properties
| Property | Mechanical Structure | Biological Structure |
|---|---|---|
| Strength | Relatively high | Relatively low (but resilient) |
| Toughness | Moderate | High |
| Self-repair ability | Limited | High |
| Energy consumption | Higher | Lower (optimized) |
| Adaptability | Moderate to high | High (evolutionary) |
2.2 Similarity Theory
Similarity theory emphasizes considering the individuality and commonality, specificity and generality, relationships between mechanical systems/components and biological individuals. By sharing the same physical essence and adhering to similarity theorems, this theory allows for an in-depth study and understanding of the structural characteristics and mechanical properties of biological individuals. By exploring the underlying physical essence and laws behind them, we can imitate the mechanical characteristics of biological structures, enhancing structural efficiency, adaptability, and robustness, achieving the purpose of optimizing and innovating mechanical structure design.
2.3 System and Optimization Theory
In system and optimization theory, organisms are viewed as complex systems that have continually evolved and adapted to their environments over time. These systems have gradually developed structures and functions that are adapted to their surroundings through constant evolution and optimization. Their structural, physiological, and behavioral characteristics reflect optimal solutions in specific environments, enabling efficient resource acquisition from the environment. Introducing biological optimization and adaptability into mechanical structure design through optimization theory allows for the creation of more intelligent, flexible, and reliable mechanical systems. This not only enhances the scientific and practical nature of the design but also drives innovation and development in the field of mechanical engineering.
In mechanical structure engineering design, to improve the mechanical properties of existing equipment or identify deficiencies in existing material designs, one can utilize the abundant principles of biomechanics and take the natural structures of organisms as reference objects. By analyzing the structural characteristics of organisms at different scales, and through systematic and holistic design, one can balance the conflicting relationships between mechanical performance, material properties, and structural dimensions. This enhances the efficiency, stability, and reliability of machinery.
3. Application of Bionic Design Methods in Excavator Tooth Design
3.1 Analysis of Excavator Structural Characteristics
Excavators are widely used mechanical equipment in engineering, characterized by complex structures and operating conditions. They play a crucial role in open-pit mining, tunnel excavation, and earthwork excavation in mountains. The structural complexity of excavators is mainly reflected in the precise calculation and design of each component, such as the working device, traveling mechanism, slewing platform, and power system. The working device of the excavator is the main load-bearing part and the main component for direct excavation operations. It is responsible for quickly and efficiently completing tasks such as earthwork excavation, loading, and transportation. The system composition includes the boom, arm, bucket, and various hydraulic cylinders.
3.2 Design of Bucket Tooth Bionic Model Based on Oriental Mole Cricket Claws
The excavating teeth of the bucket directly contact the soil and rock mass, serving as the direct tool for crushing rock and shoveling soil. Therefore, this paper employs bionic design methods, taking the claws of the Oriental Mole Cricket as a reference object, and establishes an analytical model for the R108-9 excavator to conduct simulation analysis on the mechanical properties of the arm, aiming to improve the excavation efficiency of the excavator.
The Oriental Mole Cricket is an insect with exceptional digging abilities. Observations of the forefoot claw toes of the Oriental Mole Cricket through scanning electron microscopy reveal that a crucial condition for its good adaptation to life in soil is its ability to efficiently dig burrows with its feet. Its forefeet are particularly large, and the claw toes are the most critical soil-contacting parts. This creature possesses formidable digging abilities, capable of excavating distances of 2000~3000mm within eight hours through the coupled and coordinated action of various parts.
The shape of its claw toes resembles a shovel, with both the front and side presenting a 30° wedge angle, effectively reducing friction during soil excavation, avoiding stress concentration on the claw toes, and enhancing their cutting performance and mechanical strength. Based on the bionic design method, this paper obtains the contour curves of the inner and outer sides of the Oriental Mole Cricket’s claw toes, fits the curves, replaces the upper and lower contour lines of the bucket teeth, and designs a bionic model of the excavator’s bucket teeth.