Mechanical Elastic Wheel Research Articles

Integrated yaw and rollover stability control of an off-road vehicle with mechanical elastic wheel

An integrated control algorithm of the differential braking and the active suspension to improve yaw and rollover stability of vehicles with mechanical elastic wheel (ME-Wheel) is developed. By simplifying the structure of ME-Wheel, a fitting tire model named brush model is constructed. Then, a nonlinear 8-DOF vehicle model with ME-Wheel is built up for rollover prevention, which utilizes a predictive load transfer ratio (PLTR) as the rollover index and a Kalman filter is used to eliminate the measurement noise. In order to design an integrated control algorithm, fuzzy proportional-integral-derivative (PID) methodology is adopted by simultaneous control of the yaw and roll motions. The proposed algorithm, based on the idea that makes yaw stability controller and roll stability controller work independently first, then unifies by way of weight according to fuzz control, after that, brake force distributor selects single efficient braking wheel to achieve yaw moment and one of the front braking wheels with varying brake pressure to achieve the desired brake torque and the wheel slip regulator is designed with sliding mode control technique to prevent the wheels from locking; and the active suspension system alters the stiffness of the active suspension to prevent rollover. Simulation results show that the integrated yaw and rollover stability control system could improve the handing stability of vehicle under the limit driving conditions, and prevent rollover happening.

The multi-objective optimization of a non-pneumatic wheel based on its life prediction

PurposeA novel non-pneumatic safety tire, namely mechanical elastic wheel (ME-Wheel), has been developed recently to solve problems, including tire bursting and flat tire, of typical pneumatic tires. This paper aims to predict the life of the ME-Wheel accurately and settle the problem of lower lifespan.Design/methodology/approachThis study proposes a new method to establish a novel model of virtual proving ground based on finite element analysis, and by combining with the random vibration damage analysis method, the life of an ME-Wheel is predicted precisely. Next, the weak parts and infinite life parts of the ME-Wheel are investigated from the perspective of constant life design, and an approximate response surface model is developed, which is suitable for the ME-Wheel. Then, the optimal results of the ME-Wheel are obtained, including tire modal, mass and its lifetime.FindingsIt is found that the proposed methods can provide a reliable theoretical basis for further improving the structural design and material selection of ME-Wheel parts. The results show that the improved ME-Wheel can reduce the weight and greatly improve the ability of anti-resonance, and the lifetime of ME-Wheel has significantly improved.Originality/valueA new type of non-pneumatic tire (ME-Wheel) has been developed to avoid problems with traditional tires, such as tire leaking or puncture. A new method to establish a novel model of virtual proving ground based on finite element analysis has been proposed. The weakest key component of the ME-Wheel is determined. The life, mass and modal of the ME-Wheel are optimized.

Finite element modeling of interaction between non-pneumatic mechanical elastic wheel and soil

The tire/soil interaction is an important and complex research topic in vehicle-terrain mechanics, which has a great influence on vehicle mobility and soil compaction. The purpose of this work was to develop a detailed nonlinear finite element model for parametric analysis of the interaction between mechanical elastic wheel and the soil. The three-dimensional finite element model of the mechanical elastic wheel, which considers material nonlinearity, geometric nonlinearity, as well as large contact deformation between the mechanical elastic wheel and soil, was developed based on the physical model. The reliability and accuracy of the finite element model were validated by comparing the predicted wheel static loading characteristics in rigid plane with those of experiments. The finite element model of the soil is modeled as a two-layer system and the Extended Drucker–Prager model was used to describe the nature soil properties. The deformation and stress of the soil and mechanical elastic wheel under the static loading condition were studied in detail. Moreover, the effects of the axial load on mechanical elastic wheel/soil interaction were also analyzed. The research results could offer reference for an optimum structural design of a mechanical elastic wheel and a prediction of soil compaction caused by non-pneumatic tires.

Research Progress on Kind of Non-pneumatic Mechanical Elastic Safety Wheel

Research Progress on Kind of Non-pneumatic Mechanical Elastic Safety Wheel

Thermo-mechanical coupled modeling for numerical analyzing the influence of thermal and frictional factors on the cornering behaviors of non-pneumatic mechanical elastic wheel

In this paper, we developed an advanced thermo-mechanical coupled finite element analysis (FEA) model to numerical investigate the cornering behaviors of a novel non-pneumatic mechanical elastic wheel (MEW). To construct this thermo-mechanical coupled model, first, the theoretical models of MEW involving cornering characteristics model, heat transfer model and frictional model were proposed successively. By incorporating the heat transfer and frictional model into a three-dimensional (3D) nonlinear FEA model of MEW, we established thermo-mechanical coupled FEA model consequently. By comparing the simulation results with the experimental data (tyre dynamics testing), the model was found to perform high reliability and accuracy, demonstrating the great capability in precisely predicting the cornering characteristics of MEW under practical working environments.

Multi-objective optimization for ride comfort of hydro-pneumatic suspension vehicles with mechanical elastic wheel

The new mechanical elastic wheel has the following advantages: non-pneumatic, anti-puncture, and explosion-proof. However, the larger radial stiffness is detrimental to vehicle ride comfort. To solve this problem, an integrated design method of hydro-pneumatic suspension matching mechanical elastic wheel is proposed in this paper. First, the nonlinear radial stiffness of mechanical elastic wheel is fitted by static loading experiment. Next, the mathematical model of hydro-pneumatic suspension is derived. Then, a half-car model, integrating hydro-pneumatic suspension and mechanical elastic wheel, is established. Finally, the top two optimization objectives, including vertical centroid acceleration root mean square and pitch acceleration root mean square, are optimized simultaneously, based on the Pareto multi-objective artificial fish swarm algorithm. The obtained results show that the optimization effect of multi-objective artificial fish swarm algorithm is obvious; the two optimization objectives have been optimized significantly. The proposed method that hydro-pneumatic suspension integrated with mechanical elastic wheel gains critical reference value for the design and optimization of vehicle chassis in theory and practice.

Influence Analysis of Machining and Installation Errors on the Radial Stiffness of a Non-Pneumatic Mechanical Elastic Wheel

Machining and installation errors are unavoidable in mechanical structures. However, the effect of errors on radial stiffness of the mechanical elastic wheel (ME-Wheel) is not considered in previous studies. To this end, the interval mathematical model and interval finite element model of the ME-Wheel were both established and compared with bench test results. The intercomparison of the influence of the machining and installation errors on the ME-Wheel radial stiffness revealed good consistency among the interval mathematical analysis, interval finite element simulation, and bench test results. Within the interval range of the ME-Wheel machining and installation errors, parametric analysis of the combined elastic rings was performed at different initial radial rigidity values. The results showed that the initial radial stiffness of the flexible tire body significantly influenced the ME-Wheel radial stiffness, and the inverse relationship between the hinge unit length or suspension hub and the radial stiffness was nonlinear. The radial stiffness of the ME-Wheel is predicted by using the interval algorithm for the first time, and the regularity of the radial stiffness between the error and the load on the ME-Wheel is studied, which will lay the foundation for the exact study of the ME-Wheel dynamic characteristics in the future.

Surface temperature prediction of novel non-pneumatic mechanical elastic wheel based on theory analysis and experimental verification

A theory analysis procedure has been developed here to predict the steady-state surface temperature of the mechanical elastic wheel (ME-Wheel), operating under different driving conditions. Due to the unique structure of ME-Wheel, the heat generation and heat dissipation mechanisms of ME-Wheel are discussed first. Then, the mechanical model of ME-Wheel is established to obtain the heat generation energy per unit time, while the heat dissipation energy is obtained using the theory thermal analysis of ME-Wheel. Two separate sets of testing are conducted to obtain the essential parameters of the contact patch and collect the data of the steady-state surface temperature of ME-Wheel, respectively. Then the proposed theory model has been verified. The obtained results indicate that the proposed theory model is feasible, showing the great potential to be applied in predicting the thermal conditions of ME-Wheel working under practical environment.

Simulation of steady-state rolling non-pneumatic mechanical elastic wheel using finite element method

A three-dimensional (3D) nonlinear finite element (FE) model was established for the numerical investigation of a novel non-pneumatic mechanical elastic wheel (MEW) under the steady-state rolling conditions. The reliability and accuracy of this FE model of an MEW were validated through a comparison of the numerical simulation and experimentally measured data with regard to the radial stiffness, footprint and longitudinal slipping characteristics. The validated FE model was applied to study the dynamic characteristics of the MEW under various steady-state rolling conditions using steady-state transport technology in Abaqus/Standard. The contact pressure and friction stress distribution of an MEW were studied in detail. In addition, the stress states of the key components of an MEW, such as the elastic ring and hinge group, were also analysed based on the simulation results. The main innovation of this work is the application of steady-state transport technology to a parametric analysis of the steady-state rolling of a non-pneumatic tire, the simulation results of which can provide guidance for an optimization of an MEW and other non-pneumatic tire structures.

Transient Dynamic Characteristics of a Non-Pneumatic Mechanical Elastic Wheel Rolling Over a Ditch

The transient dynamic characteristic of a tire, which has a significant effect on vehicle handling stability and ride comfort, is difficult to study in detail because of its highly non-linear behavior. In this study, the transient dynamic characteristics of a non-pneumatic wheel, called the mechanical elastic wheel (MEW), which was rolling over a ditch were investigated by the explicit dynamic finite element (FE) method. A three-dimensional FE model of MEW considering geometric nonlinearity, material nonlinearity and large contact deformation between the wheel and the road, was established. For the validation of the accuracy and reliability of the FE model of MEW, the simulation and the experimental results of the radial stiffness and footprint of MEW were compared and analyzed. A dynamic simulation of the validated FE model of MEW rolling over a ditch was conducted using the ABAQUS/Explicit program. The equivalent stress and the contact stress generated during the process of the rolling MEW impacting the ditch were studied in detail. The effect of the rolling speed on the transient dynamic characteristics was also analyzed based on the simulation results. The simulation results could provide guidance for the optimization of the MEW structure and vehicle dynamics.

Nonlinear dynamics modeling and rollover control of an off-road vehicle with mechanical elastic wheel

Nonlinear dynamics modeling and rollover stability control are the indispensable parts of automotive active safety research, especially for the military off-road vehicle with some special demands. The nonlinearity of the vehicle model refers to the nonlinear tire characteristics. By simplifying the structure of non-pneumatic mechanical elastic wheel (ME-Wheel),the change of half long grounding mark, lateral distribution stiffness along with vertical load is studied, and the corresponding fitting model is established. Then, a corrected tire brush model is constructed and a longitudinal and lateral force expression is set up. Finally, a nonlinear 8-DOF vehicle model for an off-road vehicle with ME-Wheel was built up and an active suspension control system based on rollover prediction and Fuzzy proportional-integral-derivative (PID) is designed for rollover prevention, which utilizes a predictive load transfer ratio (PLTR) as the rollover index and the Fuzzy PID controller activates only when the potential for rollover is significant as measured by the PLTR. The effectiveness of proposed tire model and vehicle model are verified by virtual simulations and experiments. Simulation results during single lane-change and fishhook maneuvers show that the PLTR index can provide a time-advanced measure of rollover propensity and Fuzzy PID anti-rollover control algorithm based on PLTR index has better stability of roll than load transfer ratio index.

Studying the Fatigue Life of a Non-pneumatic Wheel by Using Finite-Life Design for Life Prediction

To avoid pneumatic tire puncture, blow-out and other problems, a new type of non-pneumatic safety wheel called the mechanical elastic wheel (ME-Wheel) has been developed and investigated. The durability of the ME-Wheel is studied to improve its life; at the same time, the best preventive maintenance period can also be provided for the users, to ensure the safety and reliability of the ME-Wheel in operating conditions. The finite-life design method is proposed to predict the ME-Wheel life; the weakest component of ME-Wheel is ascertained by analysing its structure static strength, and the predicted model of pin for lifetime theory is established by using finite-life design method. Furthermore, the ME-Wheel durability is simulated using the finite element method (FEM) on the basis of the established virtual proving ground, and the enhancement coefficient is combined to calculate ME-Wheel lifespan. Finally, the results of theoretical calculation and simulation are verified using endurable road testing. The results show that the methods of theoretical calculation and simulation, which are applied in our paper to predict the lifespan of ME-Wheel, are highly congruent with the experimental results. Therefore, the proposed method is also entirely suitable for other mechanical structures in the durability research field.

Thermal modal analysis of novel non-pneumatic mechanical elastic wheel based on FEM and EMA

A combination of Finite Element Method (FEM) and Experiment Modal Analysis (EMA) have been employed here to characterize the structural dynamic response of mechanical elastic wheel (ME-Wheel) operating under a specific thermal environment. The influence of high thermal condition on the structural dynamic response of ME-Wheel is investigated. The obtained results indicate that the EMA results are in accordance with those obtained using the proposed Finite Element (FE) model, indicting the high reliability of this FE model applied in analyzing the modal of ME-Wheel working under practical thermal environment. It demonstrates that the structural dynamic response of ME-Wheel operating under a specific thermal condition can be predicted and evaluated using the proposed analysis method, which is beneficial for the dynamic optimization design of the wheel structure to avoid tire temperature related vibration failure and improve safety of tire.

Parameters Determination of Mooney-Rivlin Model for Rubber Material of Mechanical Elastic Wheel

In order to improve the driving safety of vehicles, a non-pneumatic safety tire named mechanical elastic wheel was developed, and the structural components of mechanical elastic wheel and the method of determining the rubber material parameters of Mooney-Rivlin model were introduced. Uniaxial tensile tests of the rubber in different parts of mechanical elastic wheel were carried out with a stretch test machine and the material parameters and of the Mooney-Rivlin model were determined by fitting the experimental data. Finite element method (FEM) was used to validate the stability of the fitted data. The results show that the obtained material parameters have high accuracy and can be a reference for the subsequent finite element simulation of mechanical elastic wheel.

Numerical and experimental investigation on the camber performance of a non-pneumatic mechanical elastic wheel

Tire safety is a pretty important performance for the vehicle. To overcome some disadvantages of the conventional pneumatic tire, a new non-pneumatic mechanical elastic wheel (ME-Wheel) is developed, and the camber performance of ME-Wheel is studied with numerical and experimental methods. A nonlinear three-dimensional finite element model of the ME-Wheel, which includes material nonlinearities, large deformation and the anisotropy of rubber–cord composites, is established. The rubber components of the ME-Wheel are analyzed by Moony–Rivlin model. With a vertical test rig, static loading tests are performed to validate the accuracy and reliability of the finite element model. Experiments and simulations under the static and rolling conditions are conducted to study the influence of different camber angles on the vertical stiffness, wheel deformation, contact pressure distribution and wheel force at the interface. The simulation results and the test results are compared and discussed in detail. The results show that the proposed method is useful for the investigation of mechanical characteristics of ME-Wheel and the later optimal design.

Research on the Structural Transfer Path of New Mechanical Elastic Wheel Vibration

To explore the double buffer damping performance of a new mechanical elastic wheel vibration (MEW), the structural transfer path of MEW vibration was studied using the evaluation method of path transfer ratio and insertion loss. According to the transmission path of the wheel's exciting force, the model of wheel vibration transfer path system was established. Combined with the analysis results of modal test, the response of the each vibration transfer path system was analyzed quantitatively, and the contribution of each transfer path of the wheel vibration was qualitatively evaluated. The analysis results indicate that the two paths have higher transfer ratio in each order natural frequency, the transfer ratio and insertion loss of path 2 are greater than the path 1 in low frequency, the transfer ratio and insertion loss of path 1 are little with the path 2 in high frequency. The analysis results reflect the objective law of the actual vibration transfer characteristics of the MEW, and provide a reference for the MEW structure optimization.

Research on vibration characteristics and its key influencing factors of new mechanical elastic wheel

This paper presents the vibration characteristics and its key influencing factors of a new mechanical elastic wheel (MEW). The MEW was modeled as a ring on elastic foundations (REF) with distributed spring stiffness in the radial and tangential directions. The general forced solutions of inextensible vibration were derived by the use of a modal expansion technique and Arnoldi method, and the accuracy of the solutions had been validated by FEM simulation and modal test under free suspension and various loading situations. The natural frequencies and mode shapes of the rotating MEW could be obtained under free suspension and various loading situations. Moreover, the effects of various rotational speed, loading and different number of hinges on natural frequencies were investigated. Finally, the effect of different number of hinges on the damping ratio of the MEW radial modes was also analyzed. The analysis results reflect the objective law of the actual vibration characteristics of the MEW, and provide a reference for the MEW structure optimization and the vibration characteristics of the whole vehicle.

Numerical analysis of the dynamic interaction between a non-pneumatic mechanical elastic wheel and soil containing an obstacle

An innovative non-pneumatic tyre called the mechanical elastic wheel is introduced; significant challenges exist in the prediction of the dynamic interaction between this mechanical elastic wheel and soil containing an obstacle owing to its highly non-linear properties. To explore the mechanical properties of the mechanical elastic wheel and the soil, the finite element method is used, and a non-linear three-dimensional finite element wheel–soil interaction model is also established. Hyperelastic incompressible rubber, which is one of the main materials of the mechanical elastic wheel, is analysed using the Mooney–Rivlin model. The modified Drucker–Prager cap plasticity constitutive law is utilized to describe the behaviour of the soil, and the obstacle is represented as an elastic body. Simulations with different rotational speeds of the mechanical elastic wheel were conducted. The stress distribution and the displacement of the mechanical elastic wheel and the soil were obtained, and the effects of different rotational speeds on the displacement, the velocity and the acceleration of the hub centre are presented and discussed in detail. These results can provide useful information for optimization of the mechanical elastic wheel.

Vibration performance analysis of vehicle with the non-pneumatic new mechanical elastic wheel in the impulse input experiment

A non-pneumatic tire appears to have advantages over the conventional pneumatic tire in terms of flat proof and maintenance free. A mechanical elastic wheel (MEW) with a non-pneumatic elastic outer ring which functions as the air of the pneumatic tire was presented. The structure of MEW is non-inflatable integrated configuration and the effect of hinges is accounted for only in tension. To establish finite element model of MEW, various nonlinear factors, such as the geometrical nonlinearity, material nonlinearity and contact nonlinearity, were considered. Load characteristic test was conducted by tyre dynamic test-bed to obtain force-deflection curves. And the validity of the finite element model was validated through load characteristic test. The vehicle vibration performance respectively based on the MEW and the radial tire was compatative studied under pulse input experiment conditions. The result showed that the vehicle concluding the new mechanical elastic wheel met the vibration performance requirements and vibration performance regularity of pneumatic tire. The results could be used as the thesis reference for the improvement of new mechanical elastic wheel.

Non-pneumatic mechanical elastic wheel natural dynamic characteristics and influencing factors

Non-pneumatic tire appears to have advantages over traditional pneumatic tire in terms of flat proof and maintenance free. A mechanical elastic wheel (MEW) with a non-pneumatic elastic outer ring which functions as air of pneumatic tire was presented. The structure of MEW was non-inflatable integrated configuration and the effect of hinges was accounted for only in tension. To establish finite element model of MEW, various nonlinear factors, such as geometrical nonlinearity, material nonlinearity and contact nonlinearity, were considered. Load characteristic test was conducted by tyre dynamic test-bed to obtain force-deflection curve. And the finite element model was validated through load characteristic test. Natural dynamic characteristics of the MEW and its influencing factors were investigated based on the finite element model. Simulation results show that the finite element model closely matched experimental wheel. The results also show that natural frequency is related to ground constraints, material properties, loads and torques. Influencing factors as above obviously affect the amplitude of mode of vibration, but have little effect on mode of vibration shape. The results can provide guidance for experiment research, structural optimization of MEW.