Axle Trailer Research Articles

Assessment of the Performance of Agricultural Tires Using a Mobile Test Bench

The performance of agricultural tires varies with the characteristics of both the terrain and the tractors on which they are mounted, which differently affect the rolling resistance, the traction capacity, and the slip. To reduce the variability of test conditions, CREA developed an original mobile test (MTB) bench which consists of a dynamometric single axle trailer pulled by a tractor and can be used both in traction performance tests (driving wheels) and in rolling resistance tests (driven wheels). A control system alternatively operates the adjustment of traction force or slip, so that each test is performed maintaining constant the desired values. The MTB underwent tests under different conditions (type of surface, pre-set values of force of traction and slip) aimed at verifying its accuracy and reliability. In a final test, two pairs of identical new tires were simultaneously mounted on the MTB and on the rear axle of the 2WD tractor that pulled it, to discover information on the different interactions occurring, under the same traction conditions, between the soil surface and each pair of tires, with reference to the relationship between the slips and the load transfers observed on the MTB and on the tractor rear axle. The results evidenced the capability of the MTB to guarantee repeatable test conditions, including field conditions, allowing comparison among the performance of different tires.

Mathematical model for farm tractors towing single axle trailer rollover prediction

Mathematical model for farm tractors towing single axle trailer rollover prediction

Mathematical model for farm tractors towing single axle trailer rollover prediction

Mathematical model for farm tractors towing single axle trailer rollover prediction

Simulation and optimization of steady rotation characteristics of middle axle trailer train

In order to optimize the steady rotation characteristics of the van-type middle axle trailer train, an efficient optimization method is proposed based on the response surface methodology and genetic algorithm. Firstly, this paper established the mathematical equations and the steady rotary simulation movement model of the van-type middle axle trailer train, and using TruckSim to simulate in standard conditions, the correctness of the model was verified by comparing with the experimental results of steady rotation. Secondly, according to the established mathematical model, the structural parameters that affect the steady rotation characteristics are analyzed. Finally, the response surface model is applied to obtain the objective function of each parameter, and the parameters are optimized by genetic algorithm(GA). According to the simulation with optimized parameters, the results show that, the comprehensive score of the steady rotation test of the middle axle trailer train was increased by 21.7%, the lateral acceleration and yaw rate of the truck was reduced by 6.65% and 9.92% respectively, and the roll angle of tractor and trailer was reduced by 19.25% and 12.5% respectively.

BACKING UP A TRAILER – AN APPLICATION-BASED VECTOR ANALYSIS PROJECT FOR 2ND YEAR CALCULUS

Abstract – A project for the second year calculus course, ME201, will be presented. Students worked in groups, make measurements using physical prototypes and performed analysis to predict behavior for the physical situation of reversing (backing up) a vehicle attached to a single axle trailer. The objectives of the project were to reinforce concepts from previous courses, including physics (vector components) and linear algebra (matrices), to demonstrate key concepts from the current course (vector products, moment vector), and to generate interest in future courses (sensors and feedback, control systems). This paper will outline the development process for the project, including the design and fabrication of the physical prototypes and the selection of test conditions. Measurements and analysis from the project, including samples of student work, will be presented.

Dynamical behavior of universal rocket transportation launching device on rough road with discrete obstacles

Functioning of the universal rocket transportation launching device in its transportation mode is analysed in the paper. The device the main function of which is to launch rocket targets used in the training process of the anti-aircraft missile systems operators needs to function effectively in transportation mode as well – it has to move with relatively high speeds in training fields maintaining sufficient stability parameters of the rocket target movement. The universal rocket transportation launching device in transportation mode is modeled as a single axle trailer with a rocket target – long cylinder attached to it by suspension represented in the form of lumped parameter elastic damping elements. Dynamical models for the analysis of its vertical and roll motion dynamics were constructed and the corresponding mathematical models derived. The excitation signal reconstructing motion of the wheels traversing discrete cleats was applied. Crossing of the longitudinally shifted left and right-side cleats was identified as the worst case from the viewpoint of rocket target motion parameters stability. The obtained results are used for rocket target suspension development.

Ground of power clutch characteristics of specialized upgraded semi-trailer and tractor

For single axle trailers consider a problem of joint effect of the tractor and trailer on the oscillations and stability of motion. A modernized system and tractor trailer coupling, characterized by further stabilizing factor. The mathematical model of cross - angular oscillation of the sprung semitrailer by which described the defining parameters fluctuations. An important critical velocity of steady motion because of the semitrailer skidding and over dropping. It is shown that cross - angular oscillation of the sprung semitrailer greatly reduce the value of critical velocity of steady motion while stabilizing stabilization time - increases it. It is shown that the use of the upgraded system connection the tractor and trailer influences the amplitude and frequency of its oscillations that ultimately could lead to a reduction of dynamic loads on components or equipment trailer, which he transports, and raising the value of critical velocity of steady motion as the entry and over dropping. Grounded power clutch characteristics of the specialized upgraded system semi-trailer and tractor.Analytical depends not only serve to further analytical studies of the dynamics of the system semi - truck, but also be the basis for development work relating to modernization of the clutch semi - trailer.

Traffic Feasibility Study for a Grade Separator at a Busy Intersection in Vellore

One of the byproduct of urbanization is traffic congestion and before suggesting any solutions to reduce congestion, understanding the present context becomes very important. Study of traffic volumes at busy intersections to find the percentage composition of different vehicle types, directional distribution and peak hour traffic volume is a first step towards understanding the present context of traffic. Hence in the present study, one of the busy intersections in Vellore, namely, Gandhi nagar intersection in Vellore-Katpadi road was selected and traffic flow data was collected using video surveys. It was found that at the selected intersection, the two wheelers and three wheelers alone share 80% of the total traffic when compared to other vehicle types. Nearly 700 trucks and multi axle trailers were observed to pass through the intersection during the analysis period of five hours. That is, on an average 2 trucks/multi axle trailers were passing through the intersection in each minute. As like in other major cities, entry of trucks and other heavy vehicles such as multi axle trailers into the city needs to be banned during peak hours for smooth flow of traffic within city limits. A highest hourly volume of 6939 PCU’s was observed between 4 and 5 pm at the selected intersection. By assuming a 10% uniform traffic growth every year, it was found that after about 4 years, i.e., in 2019, the traffic volume at the intersection may reach 10,000 PCU’s and may warrant for a grade separator or interchange at the intersection.

Performance Optimization for the Centre Axle Trailer Combination

Performance Optimization for the Centre Axle Trailer Combination

Influence Analysis of Structure Type on Turning Passing Ability of Car Transport Vehicle Combination

To analyze the influence of structure type on passing ability of car transport vehicle combination, the four basic vehicle combination models of two typical structure types, such as car transport semi-trailer road train and car transport vehicle combination with center axle trailer, have been built by using TruckSim. The turning circle test and the adaptability test on highway have been simulated on dry pavement to analyze the relationship between the structure type and the turning passing ability. The results show that the structure parameters have significant influence on the passing ability of car transport vehicle combination; three of the vehicle combination models can meet the requirements of GB 1589-2004“Limits of dimensions, axle load and masses for road vehicles”; all the four basic vehicle combination models will take up the lane beside itself when running on the up to and including third-grade highway/ramp.

Effect of Lateral Slope and Loading Pattern on Static Stability of Single Axle Trailer

Single axle trailers are most common means of transportation in rural areas. For maintaining stability of tractortrailer system, it is necessary to ascertain different factors and forces which disturb equilibrium during transportation. The effect of operating conditions and design parameters of single axle trailers on its stability were analysed using scaled physical model under static conditions. Static load tests on varying slopes were carried out using scaled physical model to determine the variation in load pattern on the trailer tyre and its hitch point. The angle of inclination along with the normal load influenced the load shift from outer wheel to inner wheel, causing instability of the tractor-trailer system. The axle position had a paramount effect on vertical hitch load. Hitch length and axle position were two major design considerations that ensured proper distribution of normal load. A normal load less than 4273 N, and the centre axle position of trailer was safe operating conditions for tractor-trailer system at lateral slope (angle of inclination) of less than 15 degrees.

Structural and functional characteristics of the lifting mechanism in universal rocket transportation launching device

The focus on the research of structural parameters and determination of functional characteristics of the rocket lifting mechanism – the important subsystem of universal rocket transportation launching device is made in the paper. The latter device is intended for the transportation of rocket-type targets and their effective launching during field training process of anti-aircraft missile system crews. The device is developed by integrating transportation subsystem in the form of single axle (light weight) trailer and launching subsystem – a six bar hydraulically actuated linkage. The launching device able to ensure necessary launching angles (in the range 30 0 -70 0 ), fast transition from the transportation to the launching mode and together meeting constraints set by motion stability requirements at transportation mode was developed. By performing structural analysis a set of links’ geometrical parameters enabling the launching angle range and having minimized vertical dimensions at transportation mode were selected. By kinematical analysis of the linkage, input parameters of actuating hydraulic cylinder ensuring constant velocity and smooth motion of the rocket guides were determined. The performed field tests of air target launching proved efficient operation of the developed rocket transportation launching device. DOI: http://dx.doi.org/10.5755/j01.mech.21.4.12261

In-Situ Health Assessment of a Poorly Executed Pre-Stressed In-Service Concrete Bridge and Suggesting a Rehabilitation Strategy – A Case Study

Abstract A study is reported on a two lane in-service pre-stressed concrete bridge having susceptible vibrations under service traffic conditions. The bridge was 1300 ft long with thirteen simple pre- cast post tensioned spans resting on in-situ bridge piers. The client reported significant vibrations under service loads and requested a solution. The bridge did not have a top wearing surface. Bridge design drawings were provided. The methodology of health assessment included the visual inspection followed by analysis with the help of drawings provided by the client. The records of concrete strengths along with prestressing protocols were missing. The static and dynamic bridge response using static and moving three different loaded vehicles (over loaded tractor trolley, unloaded 5 Axle vehicle loaded trailer and loaded 5 axle trailers) was monitored. Core samples from the bridge deck were taken. NDT, Digital half-cell and electrical resistivity readings were taken at various locations of bridge. The results indicated some design inadequacies, faulty construction methodologies, improper maintenance and lack of awareness even by the professionals to deal with such structures. The remedial measures were suggested in terms of strengthening and maintenance of bridge.

Dynamic Behaviour of a Tractor–trailer Combination during Braking

Both the theoretical and practical aspects of braking in a tractor and single axle trailer combination were examined using appropriate tests that also measured other behavioural characteristics of the combination. The results showed that braking distance or deceleration can be calculated accurately but the actual braking behaviour on icy roads can currently be determined only by testing. The results also showed that the test standards for agricultural trailer brakes can give erroneous results when single axle trailers are used. Future standardisation work in single axle trailers should employ modified test procedures. In standards and legislation, braking performance is often determined by the stopping distance or deceleration value. For brake performance the braking ratio can be calculated from the axle load and deceleration. This value gives a better figure for the torque capacity of the trailer brakes and in brake performance tests should be used instead of stopping distance or deceleration values.

A Steering System for Trailers with Multiple Axles

During a turn, at least one set of tires of the multiple- axle running gears used on heavy semi-mounted agricultural implements, such as transport trailers and liquid manure spreaders, are forced to slide sideways. This translates into accelerated wear of the tires and increased stress on the frame of the machine. A simple mechanism was designed to provide steering capabilities to multiple axle trailers. When turning, the frame of the implement slides on the steered axle and activates a steering tie-rod that rotates the front wheels in the appropriate direction so that they can follow the turning motion without sliding sideways. Steering capabilities were provided for forward as well as backward motion. Preliminary field tests proved the effectiveness of the system.

A mathematical model of the effect of trailers on tractor ride vibration

The effect of an unbalanced, single axle trailer on tractor ride vibration behaviour is studied using a two dimensional, nine degree of freedom mathematical model. Predicted results for the combination of a tractor, without a suspension, and a trailer indicate that a vertical hitch suspension would improve ride comfort and has parameters which could be achieved in practice. Hitch compliance in the longitudinal direction offers no benefits and free play should be avoided. For a tractor and trailer combination fitted with axle suspensions, the hitch should be attached to the tractor body and should not incorporate any compliance.