Effect Of Inflation Pressure Research Articles

Durability prediction of an ultra-large mining truck tire using an enhanced finite element method

Ultra-class mining trucks used for material haulage in rugged surface mining terrains experience premature tire fatigue failure in operation. Typical failures include belt edge separation, ply turn-up separation, and tread base and sidewall cracking. The use of reinforcing fillers and processing aids in tire compounds result in the formation of microstructural in-homogeneities in the compounds. This article presents an application of the critical plane analysis technique for predicting the fatigue life of the belt package of an ultra-large mining truck (CAT 795F) tire of size 56/80R63 in a surface coal mine. Experimental data obtained from extracted specimens (sidewall, tread, and belt edge region) of the tire are used to characterize the stress–strain and fatigue behavior of the modeled tire. The tire’s duty cycle stresses and strains were obtained from finite element analysis of the rolling tire in Abaqus. Fatigue life calculations were performed in the rubber fatigue solver Endurica CL. Effects of inflation pressure, tire speed, and axle load on the fatigue life of the belt package under strain-crystallizing and non-crystallizing conditions of the belt compound are discussed. Specifically, the results show the belt edges to be critical regarding crack nucleation.

Do Changes in Temperature and Inflation Pressure Affect Rolling Resistance During Road and Track Testing for Fuel Economy of Class 8 Tractor-Trailers?

Data from air cavity thermistors, tire pressure monitoring systems (TPMS), and SAE J1269 rolling resistance tests were analyzed to evaluate the significance of changes in tire pressure on rolling resistance during fuel economy tests of class 8 tractor trailers. Thermistor data show that air cavity temperatures vary, with the main increase happening during the warm-up run, and measurable cooling during the fuel measurement breaks between runs. Inflation pressure also increases by 50 - 70 kPa during the warm-up run, but once the tire has warmed up, the pressure is more stable, rarely varying by more than 20 kPa during a test run. Results of SAE J1269 rolling resistance tests allow estimation of rolling resistance force for any specified load and inflation pressure. Using the test weight of the truck, rolling resistance force was estimated for inflation pressures ranging from 550 to 860 kPa. The relationship between the inflation pressure and rolling resistance was roughly linear. The relationship was then used to estimate changes in fuel consumption due to changes in inflation pressure normalized to the cold inflation pressure. For each change of relative inflation pressure of 5%, rolling resistance would change by about 1%. Using a common return factor of a 1% change in fuel consumption for every 5% change in rolling resistance, a change in relative inflation pressure of 5% would result in a change of fuel consumption of about 0.2%. The precision of the J1321 fuel economy tests was measured to be plus or minus about 1%. This suggests that the warm-up run provided for in the test method stabilizes the tire pressure and rolling resistance, and that interference due to changes in rolling resistance during a test run or between runs is a concern only for tests that measure small changes in fuel consumption. While the results obtained here are used to assess the effect of inflation pressure on the SAE J1321 test and only apply to the particular tires tested, the method of analysis may be useful in the assessment of the effect of over- or underinflated tires on fuel consumption in the wider long-haul trucking fleet.

DC dynamic pull-in instability of a dielectric elastomer balloon: an energy-based approach.

This paper reports an energy-based method for the dynamic pull-in instability analysis of a spherical dielectric elastomer (DE) balloon subjected to a quasi-statically applied inflation pressure and a Heaviside step voltage across the balloon wall. The proposed technique relies on establishing the energy balance at the point of maximum stretch in an oscillation cycle, followed by the imposition of an instability condition for extracting the threshold parameters. The material models of the Ogden family are employed for describing the hyperelasticity of the balloon. The accuracy of the critical dynamic pull-in parameters is established by examining the saddle-node bifurcation in the transient response of the balloon obtained by integrating numerically the equation of motion, derived using the Euler-Lagrange equation. The parametric study brings out the effect of inflation pressure on the onset of the pull-in instability in the DE balloon. A quantitative comparison between the static and dynamic pull-in parameters at four different levels of the inflation pressure is presented. The results indicate that the dynamic pull-in instability gets triggered at electric fields that are lower than those corresponding to the static instability. The results of the present investigation can find potential use in the design and development of the balloon actuators subjected to transient loading. The method developed is versatile and can be used in the dynamic instability analysis of other conservative systems of interest.

Comparison of different tyre models for tyre/road noise applications

In terms of safety and environment, the reduction of noise generated by tire vibrations on roads has a significant importance. In order to study the vibration properties of a tire, various models have been presented in the literature. The main purpose of the current study is a brief review of the characteristics of some models. It is supposed that the tire is subjected to an excitation caused by the contact between the tire and the road. Subsequently, the dynamic behaviour of these models are studied and compared with each other. The effects of inflation pressure and the tread patterns on the dynamic behaviour of the mentioned models are examined. For verification, the dynamical behaviour of the tire is studied experimentally. Application of the present study can be contemplated in the prediction of rolling noise and rolling resistance.

Expansion of ologic™ Technology for Eco-Friendly Vehicles

ABSTRACT To realize a substantially eco-friendly tire that simultaneously offers appreciable drivability and traction performance, the authors have developed and proposed a large and narrow tire technology called “ologic” considering size and inflation pressure effects as one of the next-generation tire technologies. In this study, exclusive technologies in terms of tread pattern and belt construction considering a synergetic effect with compound and separation of lateral/longitudinal stiffness have been developed and evaluated through both numerical simulations and experimental analysis. As a result, appreciable improvements in terms of ologic's advantages have been observed. By using the exclusive technologies, an intermediate size of ologic tires is proposed as well for assisting adoption of ologic tires in the next generation of eco-friendly vehicles with a hope of developing a combined package of tire-suspension system and an ologic tire for making full use of ologic's advantages.

Structural testing and analysis of a braided, inflatable fabric torus structure

Inflatable structural members have military, disaster relief, aerospace and other important applications as they possess low mass, can be stored in a relatively small volume and have significant load-carrying capacity once pressurized. Of particular interest to the present research is the Hypersonic Inflatable Aerodynamic Decelerator (HIAD) structure under development by NASA. In order to make predictions about the structural response of the HIAD system, it is necessary to understand the response of individual inflatable tori composing the HIAD structure. These inflatable members present unique challenges to structural testing and modeling due to their internal inflation pressure and relative compliance. Structural testing was performed on a braided, inflatable, toroidal structural member with axial reinforcing cords. The internal inflation pressure, magnitude of enforced displacement and loading methodology were varied. In-plane and out-of-plane experimental results were compared to model predictions using a three dimensional, corotational, flexibility-based fiber-beam finite element model including geometric and material nonlinearities, as well as the effects of inflation pressure. It was found that in order to approximate the load-deformation response observed in experimentation it is necessary to carefully control the test and model boundary conditions and loading scheme.

Effect of Inflation Pressure on Tire Rolling Resistance and Vehicle Fuel Economy

Effect of Inflation Pressure on Tire Rolling Resistance and Vehicle Fuel Economy

Sensitivity analysis of truck tyre hydroplaning speed using FEA-SPH model

The hydroplaning phenomenon is a complex multi-physics problem that may affect any vehicle under wet road conditions. It is crucial to understand hydroplaning phenomenon to improve passenger safety on highways. This paper focuses on studying the hydroplaning of different truck tyres. The study includes the effect of inflation pressure, load, tread depth and water film thickness on hydroplaning speed. The tyres used in this study are the Goodyear's off-road RHD 315/80R22.5 tyre and the UOIT FEA Michelin XOne line energy T 445/50R22.5 tyre. The analysis is performed using an FEA code named Pam-Crash from ESI Group. Water is modelled using Murnaghan equation of state and smooth particle hydrodynamics (SPH) method. The simulation results are validated against Horne's equation for truck tyres. An empirical equation is developed to include various tyre parameters.

A Novel Technique to Measure the Rolling Resistance of Tyres Using Force Transducer

A novel laboratory technique has been used to measure the rolling resistance of tyres using a force transducer. The effect of inflation pressure, normal load and speed has been studied for two different bias-ply tyres—with and without treads. As anticipated, the results indicate that a treaded tyre has higher value of the rolling resistance as compared with a tyre with treads removed.

Finite Inflation Analysis of Two Circumferentially Bonded Hyperelastic Circular Flat Membranes

A finite inflation analysis of two circumferentially bonded hyperelastic circular flat membranes with uniform internal pressure is presented. The governing equations of equilibrium are obtained using the variational formulation. By making a suitable change in the field variables, the problem is formulated as a set of two coupled nonlinear two point boundary value problem (TPBVP) and is solved using the shooting method. Membranes of identical and dissimilar material properties are considered in the analysis. For dissimilar membranes, asymmetric inflation, and remarkably, deflation (after an initial phase of inflation) in one of the membranes in certain cases, has been observed. The effect of inflation pressure and material properties on the geometry of inflated configuration, state of stress, and the impending wrinkling condition of the membranes are also studied. This work has relevance to tunable inflated reflectors and lenses among other applications.

Identification of the mechanical properties of bicycle tyres for modelling of bicycle dynamics

Advanced simulation of the stability and handling properties of bicycles requires detailed road–tyre contact models. In order to develop these models, in this study, four bicycle tyres are tested by means of a rotating disc machine with the aim of measuring the components of tyre forces and torques that influence the safety and handling of bicycles. The effect of inflation pressure and tyre load is analysed. The measured properties of bicycle tyres are compared with those of motorcycle tyres.

EFFECT OF TIRES INFLATION PRESSURE , TILLAGE DEPTH AND FORWARD SPEED ON SOME FIELD PERFORMANCE CRITERIA OF TRACTOR

The research was conducted to investigate the effect of two inflation pressures for the rear tires of tractor 80 and 130 kpa with two plowing depths by using the moldboard plow 15 - 20 and 20 – 25 cm and three different speeds 2.22 , 3.22 and 5.85 km/hr on vertical vibration of driver seat , drawbar power , consumed energy , slippage percentage , tractive efficiency and power lost due to slippage . Split split plot design and randomized complete block design with three replications was used in this experiment . Results showed that the effect of inflation pressure was significant in all studied characteristics except the tractive efficiency , and the relation between the inflation pressure and every one of vertical vibration of driver seat , consumed energy , slippage percentage and power lost due to slippage was extrusive whereas the relation was inversely with drawbar power and tractive efficiency . The effect of plowing depth and forward speed was significant in all studied characteristics .

The Effect of Tire Inflation Pressure on Fuel Consumption of an Agricultural Tractor Operating on Paved Roads

Low-correct tire inflation pressure has been recommended for use in agricultural fields to improve the tractive performance and fuel economy of a tractor. However, on paved roads, higher inflation pressure appears to result in better performance. To determine the effect of inflation pressure on fuel consumption during transport operations, extensive tests were conducted using a John Deere 7810 MFWD tractor equipped with Infinitely Variable Transmission (IVT), single front 600/65R28 tires, and single rear 710/70R38 tires and operating at 40 km h-1 (25 mph) on pavement. Three different inflation pressures (62, 110, and 158 kPa, or 9, 16, and 23 psi) and four different levels of trailer mass were used during these tests. The experimental plan included three replications. During each test, drawbar load, wheel angular velocity, forward speed, total fuel consumption, and CAN bus-reported fuel consumption rate were obtained using sensors and data acquisition systems. Results clearly indicated that fuel consumption rate decreased linearly as inflation pressure increased at all load levels used in this study. On average, fuel economy in terms of distance traveled per unit fuel consumed increased by 7.3% and 11.4% at 110 kPa (16 psi) and 158 kPa (23 psi) inflation pressures, respectively, when compared to a low inflation pressure of 62 kPa (9 psi).

An improved Magic Formula/Swift tyre model that can handle inflation pressure changes

This paper describes extensions to the widely used TNO MF-Tyre 5.2 Magic Formula tyre model. The Magic Formula itself has been adapted to cope with large camber angles and inflation pressure changes. In addition, the description of the rolling resistance has been improved. Modelling of the tyre dynamics has been changed to allow a seamless and consistent switch from simple first-order relaxation behaviour to rigid ring dynamics. Finally, the effect of inflation pressure on the loaded radius and the tyre enveloping properties is discussed and some results are given to illustrate the capabilities of the model.

Assessing the thermo-mechanical TaMeTirE model in offline vehicle simulation and driving simulator tests

This paper presents the experiences using Michelin's thermo-mechanical TaMeTirE tyre model for real-time handling applications in the field of advanced passenger car simulation. Passenger car handling simulations were performed using the tyre model in a full-vehicle real-time environment in order to assess TaMeTirE's level of consistency with real on-track handling behaviour. To achieve this goal, a first offline comparison with a state-of-the-art handling tyre model was carried out on three handling manoeuvres. Then, online real-time simulations of steering wheel steps and slaloms in straight line were run on Daimler's driving simulator by skilled and unskilled drivers. Two analytical tyre temperature effects and two inflation pressure effects were carried out in order to feel their impact on the handling behaviour of the vehicle. This paper underlines the realism of the handling simulation results performed with TaMeTirE, and shows the significant impact of a pressure or a temperature effect on the handling behaviour of a car.

Effect of inflation pressure on the constitutive response of coated woven fabrics used in airbeams

Textile fabrics have gained considerable attention as reinforcement for inflatable structures. A natural challenge arising from their implementation is the proper characterization of their constitutive behavior, which involves complex inter-tow contact interactions under different loading conditions, and the effect of inflation pressure on the fabric stiffness. This paper presents an experimental investigation aimed to independently quantify the effective constitutive properties of coated, woven textile fabrics used as reinforcement for pressurized fabric tubes. When used as structural members, these tubes are commonly known as airbeams. To investigate the influence of inflation pressure on the effective fabric properties, tension/torsion experiments of airbeams were performed at various inflation pressures and under various applied axial and torsional load conditions. Good test repeatability was achieved and the results showed that the effective fabric moduli increase with internal pressure. Effective constitutive properties obtained from these experiments were used as material inputs for beam finite element models to predict the load–deflection response of woven airbeams loaded in four-point bending. The FE model results correlated well with the experimental data over the full range of loading, thus demonstrating that the test method presented is well-suited to determine independent material-level fabric properties which account for the effect of inflation pressure. Additionally, tension/torsion results of braided fabric tubes tests are presented, where good repeatability of the material properties was obtained, highlighting that the test procedure can be extended to different fabric architectures.

Experimental analysis of tyre-enveloping characteristics at low speed

In this study, experiments are conducted to investigate tyre-enveloping characteristics. Four different types of tyres are tested. Parameters such as different tyre inflation pressures, vertical loads and types of obstacles (cleats) are considered. In addition to vertical stiffnesses of all tyres, vertical and horizontal force variations while traversing different obstacles at low speed are studied. The effects of inflation pressure and vertical load on variations of force and moment are investigated. Static test results showed that after a certain vertical displacement, all curves in force–deflection diagrams plotted with and without cleat intersect regardless of cleat and tyre types, depending on the inflation pressure of the tyre, which can be called typical static tyre-enveloping characteristics. Test results at low speed show that there is a considerable influence of the vertical load on vertical and lateral force responses of a tyre.

Experimental characterization and finite element analysis of inflated fabric beams

An airbeam is a high-strength fabric sleeve with a highly flexible internal bladder that can be used as a load-bearing beam or arch when inflated. Due to their fabric construction, airbeams are inherently thin-walled structures that are prone to local buckling. In this study, airbeams were tested in bending at different inflation pressures to quantify their load–deformation response and the effect of inflation pressure on response. Tension–torsion tests of the airbeam fabric were conducted to estimate the fabric shear modulus, and the bend test results were used in conjunction with Timoshenko beam theory to estimate the fabric elastic modulus. Three-dimensional membrane finite element (FE) models were then used to predict the beam load–deformation response given these moduli. The FE models successfully predicted localized fabric buckling and softening of load–deflection response. Comparison of FE model-predicted load–deflection response with beam theory shows that conventional beam theory is accurate prior to local buckling of the airbeam fabric. The FE model and test results indicate that the consideration of work done by pressure under deformation-induced volume changes may increase beam capacity beyond previously derived theoretical limiting values.

Soil stress as affected by wheel load and tyre inflation pressure

The relative importance of wheel load and tyre inflation pressure on topsoil and subsoil stresses has long been disputed in soil compaction research. The objectives of the experiment presented here were to (1) measure maximum soil stresses and stress distribution in the topsoil for different wheel loads at the same recommended tyre inflation pressure; (2) measure soil stresses at different inflation pressures for the given wheel loads; and (3) measure subsoil stresses and compare measured and simulated values. Measurements were made with the wheel loads 11, 15 and 33 kN at inflation pressures of 70, 100 and 150 kPa. Topsoil stresses were measured at 10 cm depth with five stress sensors installed in disturbed soil, perpendicular to driving direction. Contact area was measured on a hard surface. Subsoil stresses were measured at 30, 50 and 70 cm depth with sensors installed in undisturbed soil. The mean ground contact pressure could be approximated by the tyre inflation pressure (only) when the recommended inflation pressure was used. The maximum stress at 10 cm depth was considerably higher than the inflation pressure (39% on average) and also increased with increasing wheel load. While tyre inflation pressure had a large influence on soil stresses measured at 10 cm depth, it had very little influence in the subsoil (30 cm and deeper). In contrast, wheel load had a very large influence on subsoil stresses. Measured and simulated values agreed reasonably well in terms of relative differences between treatments, but the effect of inflation pressure on subsoil stresses was overestimated in the simulations. To reduce soil stresses exerted by tyres in agriculture, the results show the need to further study the distribution of stresses under tyres. For calculation of subsoil stresses, further validations of commonly used models for stress propagation are needed.

Effect of inflation pressure on motion resistance ratio of a high-lug agricultural tyre

A single wheel tyre facility at University Putra Malaysia (UPM) was used to check the validity of Wismer–Luth and Brixius equations in predicting the motion resistance ratio of a high-lug agricultural tyre and to investigate the effect of inflation pressure. A Bridgestone 5-12, 4 ply, lug M was tested on sandy-clay-loam soil. The experiments were conducted by running the tyre in towing mode. Three inflation pressures (i.e., 166, 193 and 221 kPa) were investigated and wheel numerics ranging between 0 and 70. The analysis of covariance (ANCOVA) revealed that both inflation pressure and wheel numeric have significant effects on tyre motion resistance ratio. Regression analysis was also conducted to determine the closeness of fit for Wismer–Luth’s and Brixius’ equations in predicting the motion resistance ratio of the tested tyre. Finally, three new logarithmic models for tyre motion resistance were formulated. The advantage of reducing tyre inflation pressure from 221 (nominal pressure) to 193 kPa on the motion resistance ratio of the high-lug agricultural tyre was pronounced. However, the tyre’s motion resistance ratio deteriorated with further reduction in tyre inflation pressure from 221 (nominal pressure) to 166 kPa.