# Search Results

Viewing 1 to 5 of 5
Technical Paper

### Estimation and Reduction of Lateral Deviation (Brake Pulling) of a Vehicle due to Difference in Left and Right Wheel Brake Force

2017-09-17
2017-01-2505
This paper explains a method to estimate and reduce brake pulling of vehicles due to force difference between RH and LH brake during straight ahead braking. One of the cause of brake pulling during straight ahead braking is brake force difference between right and left brakes of front and rear axles. It is challenging to eliminate this unwanted pulling especially during panic braking in shorter wheelbase vehicles having high center of gravity (CG) and drum brake on all wheels. A mathematical model is developed to estimate amount of brake pulling from known parameters like brake force, tire properties, steering geometry, suspension hard points, vehicle CG, scrub radius, castor angle etc. Vehicle tests were conducted to measure amount of brake pulling and close correlation was observed between vehicle test results and derived model.
Technical Paper

### Mathematical Model of Dual Brake Valve for Dynamic Characterization

2013-01-09
2013-26-0150
Air brake system is widely used in heavy duty trucks and buses due to its great performance and efficiency. Dual brake valve (DBV) is one the of major and crucial component of an air brake system as it is controlling the air flow from reservoir to brake chamber during braking operation. Currently, due to its own complexity, it is very difficult for designer to optimize different parameters. As experimentation is tedious and time consuming task, hence it is very important to have mathematical model of DBV during in early design stage. Differential equations have been formulated for individual component of DBV such as primary piston, primary valve, relay piston, and relay valve etc. system level mathematical model has been formulated and implemented in Matlab/Simulink to capture the dynamic pressure characteristic of DBV. At the same time mathematical model of DBV has been created in AMESim to check the validity of approach.
Technical Paper

### Mathematical Model to Evaluate and Optimize the Dynamic Performance of Pneumatic Brake System

2015-01-14
2015-26-0082
Pneumatic brake system is widely used in heavy truck, medium and heavy buses for its great superiority and braking performance over other brake systems. Pneumatic brake system consists of various valves such as Dual Brake Valve (DBV), Quick release Valve (QRV), Relay Valve (RV), Brake chambers. Dynamics of each valve is playing a crucial role in overall dynamic performance of the braking system. However, it is very difficult to find the contribution of each valve and pipe diameters in overall braking performance. Hence, it is very difficult to arrive a best combination for targeted braking performance as it is not possible to evaluate all combination on the actual vehicle. Hence, it is very important to have a mathematical model to optimize and evaluate the overall braking performance in early design phase. The present study is focusing on the mathematical model of a pneumatic brake circuit.
Technical Paper

### Modeling and Optimization of Pneumatic Brake System for Commercial Vehicles by Model Based Design Approach

2017-09-17
2017-01-2493
Apart from being an active safety system the brake system represents an important aspect of the vehicle dynamics. The vehicle retardation and stopping distance completely depend upon the performance of brake system and the functionality of all components. However, the performance prediction of the entire system is a challenging task especially for a complex configuration such as multi-axial vehicle applications. Furthermore, due to its complexity most often the performance prediction by some methods is limited to static condition. Hence, it is very important to have equivalent mathematical models to predict all performance parameters for a given configuration in all different conditions This paper presents the adopted system modelling approach to model all the elements of the pneumatic brake system such as dual brake valve, relay valve, quick release valve, front and rear brake actuators, foundation brake etc.
Technical Paper

### Numerical Energy Absorption Assessment of Composite Materials

2012-09-24
2012-01-1923
In order to meet the stringent crashworthy regulations and to improve the fuel economy more and more composite materials have been used in automotive industry. The damage and the corresponding failure mechanisms of the composite materials during loading are entirely different from the isotropic materials. The numerical modeling of the above and prediction of the corresponding performance parameters of a composite structure are very important. Normally, the numerical modeling of the composite structures was done with a single layer of shell or solid elements. However, the approach of using single layer of elements cannot capture the effect of delamination which causes the split of the composite structures through thickness. In order to prove this an axial impact study was conducted on cylindrical pultruded glass polyester composite tubes.