Effect Of Inflation Pressure Research Articles

Racing bicycle tyres – Influence on mechanical characteristics of internal pressure, vertical force, speed and temperature

The paper describes how internal pressure, vertical force, speed and rolling surface temperature may affect the mechanical characteristics of a road racing bicycle tyre. The results were obtained from an experimental test campaign performed with VeTyT, a test-rig specifically designed for measuring the mechanical characteristics of bicycle tyres.The static deflection of tyre for different inflation pressures and vertical loads was measured to determine the static tyre vertical stiffness. Results for tyre rolling on flat track or on a drum were compared. Dynamic analyses were focused on evaluating the effect of inflation pressure and vertical load, for two rims featured by different lateral stiffness. Then, the respective effects of speed and of temperature of the rolling surface on the lateral force were considered.Stiffer rims can ensure higher values of cornering stiffness. In addition, higher inflation pressure is recommended only for heavy vertical loads. For low vertical loads, too inflated tyre results to be less performant, i.e. to show lower values of cornering stiffness. The speed can affect the mechanical characteristics of bicycle tyres mainly for slip angles less than 1.5°, while the temperature of the rolling surface is the most affecting parameter for slip angles larger than 3°.

Effect of inflation pressure on tyre forces under combined-slip conditions based on the UniTire model

Effect of inflation pressure on tyre forces under combined-slip conditions based on the UniTire model

Effect of inflation pressure on tyre forces under combined-slip conditions based on the UniTire model

Effect of inflation pressure on tyre forces under combined-slip conditions based on the UniTire model

The Vertical Force Estimation Algorithm Based on Smart Tire Technology

The real-time monitoring of the vertical force of the tire is the basis for ensuring the driving safety, handling stability, fuel economy and the riding comfort of the vehicle. An algorithm for the vertical force of the tire estimation based on the combination of intelligent tire technology and neural network theory is herein proposed. Firstly, the finite element model of the 205/55/R16 radial tire was established by ABAQUS and the validity of the finite element model was verified through static experiment and dynamic experiment. Secondly, the effects of inflation pressure, speed, load and tread wear on the tire contact patch length and the radial displacement at the virtual acceleration sensor were analyzed based on the finite element analysis method and control variable method. Finally, three kinds of the vertical force prediction algorithms based on the GA-BP neural network algorithm were established, and the network performance of each prediction model was tested. The results show that the vertical force prediction model with inflation pressure and the peak value of radial displacement as the characteristic input parameters has the highest prediction accuracy and the shortest calculation time. At the same time, the mathematical formula of the Model 3 was built.

Effects of Inflation Pressure and Wall Thickness on Gripping Force of Semi-Cylindrical Shaped Soft Actuator: Numerical Investigation

Soft robotics using Pneumatic Network actuators (Pneu-Net) is a developing field that has a promising future for variety of applications involving delicate operations such as biomedical assistance. The interaction between geometry and the performance of the actuator is an important topic which has been studied by many researchers in this field. However, there is a lack of investigation on the relationship between gripping capability and geometrical parameters of soft actuators. Especially, there is a need to shed more light on the effects of wall thicknesses on the gripping force developed. In the present study, a semi-cylindrical chambered PneuNet soft actuator is numerically investigated to evaluate the effects of pressure and wall thickness variations on its performance characteristics. The results revealed that increasing the restraining layer thickness (RLT) aids the bending capability of the actuator whereas increasing the chamber wall thickness reduces it. Therefore, maximum bending of the actuator is achieved at the combinations of minimum wall thickness and maximum RLT. At these geometrical configurations of maximum bending, the deformation-pressure relationships followed a sigmoidal function and tended towards linearity with increasing wall thickness and decreasing RLT. The gripping force showed an exponential increase with increasing working pressures and wall thicknesses. The maximum gripping force increased cubically with increasing wall thicknesses at their respective maximum working pressures, which was modeled using a polynomial regression model (R2=99.79%).

Experimental and Numerical Studies on the Inflatable Recyclable Anchor in the Tube Piece Type Based on the Soil-Anchor Interaction Mechanism

This paper deeply studies the characteristics and “uplift bearing capacity” of a novel type of inflatable recyclable anchor in the tube piece. The proposed novel inflatable recyclable anchor in the tube piece type comprises a metallic rod, an inflatable anchorage device, and a recovery device. Fifteen field uplift tests are conducted to investigate the effects of inflation pressure, thickness of the steel disc, embedment length, and time lapse between anchor inflation and pullout on “the uplift bearing capacity.” The results show that “the uplift bearing capacity” of the novel inflatable anchor in the tube piece type increases with the increase of inflation pressure, thickness of the steel disc, and embedment length. With the increase of inflation time, “the uplift bearing capacity” of the novel inflatable anchor experiences an increase after first experiencing a decrease. The finite element analysis method is used to establish a numerical analysis model of the inflatable anchor, and the distribution law of the tensile stress of the surrounding soil during the pullout of the anchor is analysed. Compared with the traditional grouted anchor, the proposed anchor has an obvious superiority in recyclability, reusability, and swifter formation of anchorage force and thus is a resource-saving and environmentally friendly anchor technology.

Impact of a pressurised membrane: Contact time

Pressurised membranes are used in various situations involving humans (protections, sports, etc). In this context, impacts mechanics of membranes is critical since under or over inflated membranes may create injuries. The effect of inflation pressure on contact time is investigated on a model experiment using a spherical membrane. Both gas pressure and impact speed decrease contact time. Direct measurements of gas pressure and temperature variations indicate an adiabatic compression in strong interaction with the membrane. The contact time of an inflated membrane is described by three dimensionless numbers, (i) the relative inflation P˜, (ii) the presso-elactic number PE that considers the gas-membrane interaction and (iii) the presso-inertial number IP that scales membrane inertia to pressure forces. A model of pressurised membrane impact is provided and compared with experiments. It shows that contact time depends mainly on IP with corrections on PE and P˜.

Illustrating Membrane-Dominated Regimes in Pressurized Thin Shells

Pressurized thin-wall structures cover a broad range of applications, including storage tanks, pressurized rubber flood barriers, and large span enclosures. To accurately model such structures, the analyst must select the appropriate mechanical formulation (e.g.membrane vs shell). Membranes are assumed to have negligible bending stiffness and respond to compression by wrinkling; shells resist axial compression (before buckling) and bending efficiently. While theoretical research on these differences is vast, this study aims to explicitly clarify the consequences of this choice and permit a comparison of error between membrane and shell formulations. Therefore, this paper presents a parametric study of canonical pressurized thin-wall structural geometries (i.e.semi-cylinder, hemisphere) to illustrate the transitions between membrane and bending dominant behavior. The mathematical models of a pneumatic 5-parameter shell and membrane are presented and employed to quantify the effects of variables such as thickness and geometry on the amount of membrane, bending, and shear energy. The effects of inflation pressure, self-weight, and hydrostatic loads are also considered. The graphical results, presented in terms of dimensionless quantities in the design space, are general and should be of interest to the theorist and practitioner alike.

Numerical Investigation into the Natural Convection of Cryogenic Supercritical Helium in a Spherical Enclosure

As an ideal pressurized gas, helium, especially supercritical helium, has been widely used in the pressurization system of various launch vehicles and spacecraft. This work mainly focuses on the natural convection of cryogenic supercritical helium in a spherical enclosure. Firstly, a three-dimensional numerical model is established and verified with experimental data. Then, the effects of inflation pressure and heating power on the flow and heat transfer characteristics are simulated. At the same time, the relationship between the Rayleigh number and Nusselt number is studied in detail. Finally, an improved natural convection heat transfer correlation modified by introducing the density ratio is obtained. The results show that the increase of the inflation pressure in the cavity is helpful to enhance the natural convection heat transfer of the cryogenic supercritical helium, and the temperature distribution in the cavity tends to be more uniform when the inflation pressure in the cavity increases. As to the improved natural convection heat transfer correlation, the average error between the simulation results and the calculated values is approximately 8%, which can better describe the natural convection heat transfer of cryogenic supercritical helium in the spherical enclosure.

Analysis of the Effect of Inflation Pressure on Vehicle Handling and Stability under Combined Slip Conditions Based on the UniTire Model

Analysis of the Effect of Inflation Pressure on Vehicle Handling and Stability under Combined Slip Conditions Based on the UniTire Model

Numerical analysis of rubber tire/rail contact behavior in road cum rail vehicle under different inflation pressure values using finite element method

With the advent of Rail cum road motors there are great demanding situations earlier than Indian railways. Railway Engineers had been for all time interested by the metal wheel-Rail and Rubber tire-Rail contacts. These tiny interfaces govern the dynamic overall performance of avenue cum rail motors via the masses it transmits and, like every high-strain attention sector, it's far subjected to severe damage phenomena. The paper deals with modelling and simulation of the static behaviour of a radial mini truck tire of a proposed road cum rail automobile in touch with rails. The Finite element technique via the ANSYS software program is used to obtain the static behaviour of the rubber tire in contact with rail underneath inflation stress values. The primary goal is to carry out a finite detail analysis and computationally compare the overall performance of a stationary rubber tire along with rim on rails with the aid of changing the inflation stress so that corresponding overall performance parameters like equivalent strain in rubber tire and rims, deformation and call patch of rubber tire are expected and the effect of inflation pressure on these parameters can be understood.

Tyre inflation pressure effects on the transient handling performance of a multipurpose protected vehicle

Tyre inflation pressure effects on the transient handling performance of a multipurpose protected vehicle

Tyre inflation pressure effects on the transient handling performance of a multipurpose protected vehicle

Tyre inflation pressure effects on the transient handling performance of a multipurpose protected vehicle

Ascertainment of driving lead of tractor front wheels as loaded by draft force

• Driving lead of tractor front wheels was ascertained as loaded by draft force. • The driving lead nonlinearly augmented when draft force augmented. • To manage driving lead, inflation pressure adjustment of tires is emphatically suggested. • Ballast weight application can be considered as another managing suggestion. Preceding researches proved that improper driving lead of tractor front wheels results in power circulation in transmission system, excessive wear of tires, premature rough ride, lower braking performance, and higher fuel consumption for mechanical front wheel drive (MFWD) tractor in rectilinear motion. For the first time, this study attempts to ascertain the driving lead dependency on draft force for the MFWD tractor which has not been yet addressed in the state of the art. To eliminate the effect of inflation pressure of high-lug radial tires on the driving lead, it was kept constant at 204 and 136 kPa for the front and rear wheels, respectively. The tractor was loaded by draft force required for fully mounted plow implement. It was found that the driving lead nonlinearly augmented from 1.86 to 8.08% as draft force augmented from 7.88 to 37.81 kN. Possible explanations and interpretations for this result have been completely documented in the paper. Overall, in order to manage the driving lead in admissible range in the loading operations, inflation pressure adjustment of the tires by means of commercial central tire inflation system is emphatically suggested as the first priority rather than ballast weight application.

Performance study of RTV-2 Silicone Rubber Material For Soft Actuator by Experimental and Numerical methods: The Effect of Inflation Pressure and Wall Thickness

The expensive nature of currently used materials in the soft robotic industry demands the consideration of alternative materials for fabrication. This work investigates the performance of RTV-2 grade silicone rubber for fabrication of a soft actuator. Initially, a cylindrical actuator is fabricated using this material and its performance is experimentally assessed for different pressures. Further, parametric variations of the effect of wall thickness and inflation pressure are studied by numerical methods. Results show that, both wall thickness and inflation pressure are influential parameters which affect the elongation behaviour of the actuator. Thin (1.5 mm) sectioned actuators produced 76.97% more elongation compared to thick sectioned, but the stress induced is 89.61 % higher. Whereas, the thick sectioned actuator (6 mm) showed a higher load transmitting capability. With change in wall thickness from 1.5 mm to 6 mm, the elongation is reduced by 76.97 %, 38.35 %, 21.05 % and 11.43 % at pressure 100 kPa, 75 kPa, 50 kPa and 25 kPa respectively. The induced stress is also found reduced by 89.61 %, 86.66 %, 84.46 % and 68.68 % at these pressures. The average load carrying capacity of the actuator is found to be directly proportional to its wall thickness and inflation pressure.

Analysis and Prediction of Tire Cornering Properties for Different Inflation Pressures Based on Deflection Control

ABSTRACT The variation of inflation pressure has an important effect on the mechanical characteristics of tires that can affect vehicle performance, so the influence of inflation pressure should be taken into account in high-precision tire models. Much research has focused on tire mechanical characteristics under different inflation pressures and modeling methods, such as the Improved Magic Formula/Swift Tire model developed by Schmeitz et al. that takes inflation pressure into account. Based on a large number of tire testing data under different inflation pressures, an empirical model can be obtained, but numerous tire tests are expensive and cannot reveal the mechanism. In previous studies, most tire tests were based on load control, wherein the load is constant while the footprint, carcass, and belt stiffness can change with the variation of inflation pressure, making the cornering characteristics much more complicated. Herein, a method of deflection control is used and the contact patch is well maintained. The effect of tire inflation pressure is simplified to be the change of structure stiffness and averaged contact pressure. The effect of inflation pressure on cornering properties under deflection control is systematically observed under different tire deflection values. In addition, a prediction model extended from the Magic Formula model is proposed. The model of Schmeitz et al. [1,2] needs test data from at least three inflation pressures; the model proposed herein requires tests at only two inflation pressures. The validation shows that this prediction method has good accuracy, almost the same as that of the model of Schmeitz et al. The error index of the lateral force is at most 2%, and the error index of the self-aligning torque is 4% at the maximum.

UniTire Model under Combined Slip Conditions with the Coupling Effect of Inflation Pressure and Vertical Load

UniTire Model under Combined Slip Conditions with the Coupling Effect of Inflation Pressure and Vertical Load

Experimental Characterization of Tensairity Beams

Tensairity is a new structural concept towards a sustainable architecture, combined from struts, cables, and an airbeam. In Tensairity, each bearing component is working in the most favorable conditions: struts are only compressed, cables are only tensioned and the airbeam stabilizes the system. Thus, Tensairity beam will be much lighter than a conventional beam. The bearing capacity of this type of beam depends not only on the material property but also on the inflation pressure in the airbeam and the tension in the cable. And this tension strongly depends on the cable anchoring method. This paper presents an experimental investigation aimed to the bending of a Tensairity beam submitted to a homogeneous distributed load. Prototypes in full-scale tests of Tensairity beams will be manufactured. Effect of inflation pressure, airbeam size, and cable anchoring method to structural stiffness will be studied experimentally. The obtained experimental results are in high agreement with those of an independent theory.

Structural behaviour of inflatable PVC fabric cylindrical tubes

Inflatable structures are light weight structures that have often been proposed for aerospace applications. They are light in weight, easily manufacturable and foldable. Thus, they can be easily transported and deployed in space. However, the proper characterization for their properties of these structures is still missing.The work done in this paper aims at studying the structural properties of inflatable cylindrical tubes, manufactured from PVC fabric. The cylindrical tubes are fixed as cantilever beams and subjected to a load at the beam tip. Samples of different sizes are tested under different inflation pressures and loads. Load-deflection curves are recorded for each test. Results show that the beam stiffness increases with the increase of inflation pressure and beam cross sectional area. The inflatable beams show linear behaviour up to a certain critical load at which wrinkling occurs. Beyond this load the behaviour of the beam becomes nonlinear and can be unstable. Hysteresis phenomenon is also observed during the unloading of the beam. In addition, Free vibration analysis was conducted to study the effect of inflation pressure on the beam natural frequency. This work is a part of project aiming to design and manufacture an inflatable wind turbine blade to overcome the drawbacks of conventional blades.

Development of a flexible belt on an elastic multi-stiffness foundation tire model for a heavy load radial tire with a large section ratio

Abstract The study investigates the planar vibration characteristics of a radial tire with a large section ratio for a heavy load vehicle. A proposed tire model with a flexible belt on an elastic multi-stiffness foundation is investigated via theoretical modeling and an experimental modal analysis. Additionally, the parametric identification of the proposed tire model is discussed. When compared with the conventional sidewall stiffness model for general car tires, the analytical multi-stiffness function of a large section ratio sidewall is derived by combining the membrane feature caused by inflation pressure and the structural deformation caused by sidewall curvature. The Euler beam model specifically assesses the circumferential vibration of the flexible belt. Additionally, we combine the sidewall multi-stiffness function of the membrane pre-tension stiffness, and the structural deformation stiffness is integrated into the flexible belt model. The effect of inflation pressure on the circumferential vibration of the flexible belt is investigated via the experimental modal method and theoretical Euler beam model. The stretching, bending, shearing deformations, and stiffness characteristics of the curved sidewall arc are derived via the virtual work principle. The nonlinear stiffness characteristic of the tire sidewall is calculated relative to the radial deformation of the sidewall segment. The effect of the inhomogeneous section area on the multi-stiffness function is discussed. The experimental and theoretical results indicate the following: (1) The multi-stiffness function of the curved sidewall assesses the pre-tension membrane feature and structural deformation, which is related to the inflation pressure, structural curvature, and material properties; (2) the multi-stiffness function of the curved sidewall is nonlinear relative to the radial deformation of the sidewall arc, and the nonlinear characteristic is highlighted with high inflation pressure; (3) the inhomogeneous feature of the section area affects the multi-stiffness of the curved sidewall. Given the combined sidewall multi-stiffness function of the membrane feature and structural deformation, the elastic foundation model acts as an independent module to enrich the flexible belt beam model. Additionally, a flexible belt on an elastic multi-stiffness foundation tire model is suitable for a radial tire with a large section ratio of a heavy load vehicle or tires under impulsive loads and large deformations.