Research On The Bionic Mechanism And Coupled Bionic Design Method Of Green Tire Pattern Structure

Based on the "Green Tire Technical Specifications" in China,it clearly stated that our country's tire products should develop in the direction of low driving noise,low fuel consumption,excellent handling stability,shorter braking distance,and better wear resistance,aiming to comprehensive develop from energy saving,environmental protection and safety.However,in the design process of tire products,it was often at the expense of other performances in order to pre-enhance a certain performance.There were contradictory characteristics among the performances of tires that were not yet clear.Even if it tried to improve the ratio of rubber materials and the structure of the tire carcass,it also was difficult to effectively solve the contradictory characteristics between the performances of tires.With the integration of the bionic concept in the design of tire tread pattern structure,exploring suitable bionic sources and using bionics methods to design the tire tread pattern structure was expected to become a method to achieve synergistic improvement of many performances of tires.Hence,on the one hand,this paper selected the tire noise and grip performances as research objects to explore the mechanism of the contradictory characteristics between them;On the other hand,the biological function characteristics such as good vibration reduction,quietness,and strong grip displayed by the domestic cat's paw pad were selected as the bionic source,and the AU01 205/55R16 tire was selected as the bionic application object,and through the coupled bionic design of its tire tread pattern structure in order to achieve the purpose of synergistic improvement of its noise and grip performance.Firstly,in order to clarify the mechanism of the contradictory characteristics between the tire noise and grip performances,based on the VIC-3D full-field non-contact deformation test system,the deformation characteristic parameters of the tread grounding area of 10 tires under the rated working conditions were obtained;The correlation analysis method was used to screen out the deformation characteristic parameters that were highly correlated with tire noise and grip performances,and with the help of Isight software,a first-order linear regression equation for characterizing tire noise and grip performances was constructed to facilitate qualitative and quantitative analysis.On this basis,the deformation characteristic parameters that were highly correlated with tire noise and grip performances were used to clarify the mechanism of the contradictory characteristics between the two performances,and at the same time revealed that the transition area outside the tread was the main contradiction area between tire noise and grip performances.In addition,the DOE(Design of Experiments)method was used to analyze the contribution of different sub-regions of the tread to tire noise and grip performance.The numerical value indicated that the grounding sub-areas with the largest contribution to the tire noise and grip performances were the tread center area and the outer shoulder area respectively.Secondly,in order to reveal the realization mechanism of the biological function characteristics displayed by the domestic cat paw pad,the in-depth researches were carried out from the two aspects of histology and kinematics of the domestic cat's paw pads.On the one hand,through the tissue staining observation,scanning electron microscope observation and quasi-static compression test of the paw pads,the microstructure and mechanical characteristics of the paw pads were revealed.The research results showed that the microstructure of domestic cat's paw pads present a three-layer coupling structure,and each had different material mechanical properties,such as the rigidity and elasticity of the stratified epithelial layer,the viscoelasticity of the dermis layer,and the superelasticity of the subcutaneous tissue layer;At the same time,the coupling structure of the domestic cat's paw pad made it characterized as a variable stiffness mechanical property under the action of external force.On the other hand,with the help of the Tekscan pressure distribution measurement system and the VIC-2D non-contact deformation test system,the grounding mechanical characteristics of domestic cat's paw pads during they were moving at different gaits were tested,analyzed and compared.By comparing the differences in the grounding geometry,grounding pressure,grounding deformation distribution and other grounding mechanical characteristics of the domestic cat's paw pads in the different gaits,the adaptive adjustment law and biological characteristics of the domestic cat's paw pads in terms of form,structure and mechanical effects were analyzed.Furthermore,from the perspective of grounding pressure,the realization mechanism of the biological function characteristics of good vibration damping of the domestic cat's paw pad was revealed,and the realization mechanism of the biological function characteristics of the domestic cat's paw pad strong gripping was revealed from the perspective of grounding geometry and ground deformation distribution.Thirdly,the realization of biological functional characteristics was the result of a number of dependent and mutually influencing biological coupling elements following an appropriate realization mechanism.On the basis of clarifying the biological coupling elements that existed in the biological function of the domestic cat's paw pads,the biological coupling elements suitable for tire products were selected as the bionic source to conduct bionic design on the tire tread pattern structure to realize the equivalent transplantation of the functional characteristics of biological coupling elements.The bionic application of the swing deformation characteristics of the domestic cat's paw pad during the grounding process was realized by the asymmetric layout design of the imitated honeycomb hexagon structure in the central area of the tread that had the greatest contribution to the tire noise performance,and verified by the finite element simulation analysis that the bionic design helped the tire achieve the biological function characteristics of good vibration reduction and quietness similar to that of the domestic cat's paw pads.Finally,the AU01 205/55R16 tire was selected as the bionic application object,in order to transplant the realization mechanism of the biological function of the domestic cat's paw pads into the tire product.By using the optimal structure through coupled the mechanism bionic approach,the design had completed the bionic modification of tread pattern structure.Through the finite element simulation analysis,it found that,compared with the original tire,the coupled bionic tire improved the radial excitation force during the rolling contact between the tread and the road surface,increased the strain distribution in the X direction in the tread area,and achieved a noise reduction of1.16 d B and an increase in grip of 53.21 N.At the same time,in order to improve the bionic design theory method of green tire pattern structure,this paper proposed a simulation performance evaluation method suitable for coupled bionic tire products based on the concept of coupling simulation performance.The evaluation results showed that the imitation performance of the coupled bionic tire was increased by 12.2%compared with the original tire.