Qiushi Zhang

This study aimed to investigate the relationship between the static stiffness of non-pneumatic tires (NPTs) and the design parameters of composites spokes and shear bands using the finite element (FE) method. The stress–strain curve of the rubber material was fitted using the neo-Hookean constitutive model. Subsequently, key design parameters, including the reinforcement plate thickness and constitutive parameters of the spoke and shear band materials, were selected based on the NPT structure. FE simulations were performed on multiple sets of different parameter design schemes for the NPTs, and polynomial models for the vertical, lateral, and longitudinal stiffnesses were established using response surface analysis. The sensitivity analysis results indicated that the thickness of the reinforcement plate significantly influenced the three-dimensional stiffness, whereas the constitutive parameters of the spoke and shear band materials had a relatively minor impact. Finally, multi-objective optimization was employed to determine a design scheme with maximum longitudinal stiffness while ensuring vertical load-bearing capacity. Under the premise of ensuring the vertical load-bearing capacity, the longitudinal stiffness increased by 39.1% and 32.9% in the forward and backward directions, respectively. This method can be used to predict the three-dimensional stiffness of NPTs under different design parameter schemes or to optimize the setting parameters of NPTs based on the desired target stiffness, facilitating the rapid design of the three-dimensional stiffness of NPTs.

This study aims to analyze the load-bearing characteristics of non-pneumatic tires with composite spokes using experimental and finite element simulation methods and to establish a mechanical analysis model based on the Timoshenko beam theory. Subsequently, experiments were conducted on carbon fiber-reinforced plastics and rubbers to establish the corresponding constitutive model. A finite element model of the non-pneumatic tires with composite spokes was also developed. The main structural and material parameters were selected, and their correlation with the vertical stiffness of the non-pneumatic tires with composite spokes was studied using response surface methodology. The stiffness characteristics of the composite spokes were simplified, and a load-bearing characteristic analysis model was established. The results indicated that among the parameters of the reinforcement plate structure and rubber, the constitutive parameter C₁₀ of the rubber in the spokes had the greatest impact, with a comprehensive influence value of 319.83 N/mm. Under a load of 5000 N, the load-bearing characteristic analysis model results were consistent with those of the finite element simulation, with a maximum relative error of 7.49%. The proposed load-bearing characteristic analysis model can assist in the rapid design and performance prediction of non-pneumatic tires with composite spokes.

Solid polymer electrolytes (SPEs) encounter the challenge of balancing high ionic conductivity and mechanical strength. Ionic liquids, which are among the contenders to be used in high-performance supercapacitors, have difficulty infiltrating commercial polyolefin separators for combined applications. In this study, a novel SPE involving uniform infiltration in the micropores of commercial polyolefin separators with polyethylene oxide (PEO), lithium salt, and different proportions of added ionic liquid was developed. The composite membranes combining ionic liquid-filled SPE with polypropylene (PP) microporous separators simultaneously achieve excellent mechanical strength and high-ionic conductivity. The low wettability of pure ionic liquids and commercial polyolefin-based separators is addressed. The 70 wt% IL-filled solid electrolyte composite membrane (PLI(70)@PP) exhibits a high ionic conductivity (2.9 × 10⁻³ S cm⁻¹), low resistance at the electrolyte–electrode interface and excellent mechanical strength (128 MPa) at 25 °C. The all-solid-state supercapacitor using PLI(70)@PP exhibits a specific capacitance of 158 F g⁻¹ at 0.1 A g⁻¹ and stable cycle performance. The proposed method can be performed via high-volume roll-to-roll processing to obtain high-performance all-solid-state supercapacitors (ASSCs) for engineering applications.

Rolling resistance (RR) is key research content for developing low-carbon energy-saving tires, and the resultant change in the tire temperature field exerts a crucial impact on tire performance. Currently, there is no accurate and systematic analysis method for solving the steady-state temperature field (SSTF) and RR of tires with complex patterns and non-pneumatic tires (NPTs), which are characterized by discontinuous structure in the circumferential direction. A solution strategy that entails SSTF and RR based on explicit transient rolling analysis and thermal-mechanical coupling is proposed and its accuracy is verified using the SSTF test pertaining to the low-speed and low-load capacity non-pneumatic tire (LSL-tire), which exhibits a 7.56% and 6.94% average temperature deviation for the outer surface center of the tread and for the outer surface center of spokes, respectively. Uniaxial tensile mechanical property tests and dynamic mechanical analysis (DMA) of the utilized rubber and polyurethane (PU) materials were conducted, and their specific heat capacity, thermal conductivity, and density were tested. Based on three-dimensional nonlinear finite element simulation and considering the characteristics pertaining to the loss factor of viscoelastic materials changing with temperature, the SSTF and RR of the LSL-tire under different loads and velocities were analyzed. The results indicate that the influence of load and speed on the SSTF of LSL-tire is quite significant, whereas the influence of speed on the RR is not apparent. For all conditions, the highest steady-state temperature points of the tread are located in its center, and in the spokes they are located in the joint between spokes and the outer ring; the spokes contribute the most to the RR, followed by the tread.

A high load capacity non-pneumatic tire (HC tire) was designed and manufactured to solve the problems of air leakage, puncture, blowout, shoulder void, and delamination, which occur in traditional high load capacity tires, as well as significantly increase the unit load of tires. Experiments and numerical simulations were conducted to investigate the static stiffness properties of the HC tire. Additionally, the manufacturing process of the tire was highlighted. The tire mainly comprised polyurethane and silicon manganese steel, and a ‘π’-shaped support substructure was adopted. The tread structure was made up of a built-in spiral steel ring and a non-steel ring. The uniaxial tensile mechanical properties of the used metal and elastomer materials were tested, and the linear elastic constitutive model and Marlow constitutive model, respectively, were used to describe their mechanical characteristics. The stiffness properties of the HC tire, including torsional, longitudinal, vertical, and lateral stiffnesses, were evaluated using a tire comprehensive stiffness tester. Nonlinear finite element models of the HC tire were established, and their accuracies were verified through vertical stiffness tests. The stiffness properties of the HC tire in other directions were simulated as well. An in-depth comparative analysis of the simulation and experimental data was performed. The results demonstrated that the unit load of the unreinforced HC tire was 2.972 times and 1.615 times higher than that of the solid tire and pneumatic tire, respectively. The spiral steel ring embedded in the tread increased the vertical and longitudinal stiffness but reduced the torsional stiffness of the HC tire, thus reversing the variation trend of the lateral stiffness at the 0° and 5° test points. The findings can serve as a reference for theoretical research on, and the structural optimization of, non-pneumatic tires with a high load capacity.

This article deals with initial material selection and design method of long fibre-reinforced thermoplastic (LFT) based on impact resistance requirements. In this study, effects of material properties and impact condition, including total fibre thickness, fibre aspect ratio and impactor diameter, on the minimum penetration energy of LFT plates are analysed based on experiments and validated numerical models. Mathematical expression is established between them. Applicability of the original model for LFT plate with different fibre aspect ratios subjected to different impactors is discussed. The minimum penetration energy is used as the bridge between energy absorption characteristics and material parameters, impact condition. Finally, an updated theoretical model for energy absorption analysis is proposed. We conclude that the updated semi-empirical model is a valuable tool for a first stage material selection and design.