B5866 - Terramechanics for Off Highway Vehicles

Learning outcomes

Students will gain an in-depth knowledge of the dynamics of off-road vehicles in relation to the operating environment (i.e., the ground). They will learn the fundamentals of soil mechanics and the mathematical models used to describe its interaction with vehicles and agricultural machines. Students will learn how to use these models to predict the performance of off-highway vehicles in terms of traction and vehicle mobility, the influence of vehicle design on these parameters, and how to select an appropriate vehicle configuration for a given vehicle, environment, and operation. Students will also learn how to plan and conduct field test measurements and how to statistically analyse field data for mission characterisations.

Course contents

Overview about the course and terramechanics (2 hours / 0.2 CFU)

Description of off-highway vehicles and their main missions (8 hours / 0.8 CFU)

Description of auxiliaries components of off-highway vehicles (i.e., PTO, power lift, drawbar hitch, hydraulic remotes) (8 hours / 0.8 CFU)

Soil engineering parameters and in particular: soil classification, soil shear strenght, soil pressure sinkage, soil bearing capacity (10 hours / 1 CFU)

Testing of soil engineering parameters (6 hours / 0.6 CFU)

Description of traction devices (4 hours /0.4 CFU)

Performance evaluation of tracked and wheeled off-highway vehicles (4 hours /0.4 CFU)

Mobility requirement, and description of tyres and tracks (4 hours / 0.4 CFU)

Description of power delivery efficiency and traction efficiency (4 hours / 0.4 CFU)

Full-scale vehicle test methods (4 hours / 0.4 CFU)

Modeling vehicle - ground performance: tracked vehicles, and rigid and flexible wheel on soft soils (10 hours / 1 CFU)

Stability of off-highway vehicles (2 hours / 0.2 CFU)

 

 

Readings/Bibliography

Course material:

• PDF notes provided by the teacher. To aid class learning process, these notes should be printed before each lecture. These notes will be provided with Virtuale service and they will be accessible to those subscribed to the distribution list.
• Wong, J. Y. (2009). Terramechanics and off-road vehicle engineering: terrain behaviour, off-road vehicle performance and design. Butterworth-heinemann.

Teaching methods

Lectures conducted in presence.

During the course, seminars will be planned and will be held by experts from the industry.

Assessment methods

The course is a module of "Power Transmission and Terramechanics for Off-Highway Vehicles" together with the course of "Power Transmission for Off-Highway Vehicles". Consequently, the final assessment will be the average value of the assessment of each course.

The final assessment will consist of two parts:

Group project
Students, organized in groups working on a terramechanics model of an off-highway vehicle. The project must be submitted at least 3 working days before the exam date and containing:

• the eventual dataset;

• a Matlab code developed as a Live Script, properly commented, executable on computers other than the one used for development, and including interpretative comments on the graphs produced in the Live Script.

The students struggling in identifying the topic are encouraged to contact the professor for a preliminary discussion.

The project will be discussed during the oral exam.
The maximum score that can be awarded for the project is 20 points.

Individual written exam

It will consist on two written questions each giving up to 6 points.

The online exam confirmation is mandatory. The course outcome will be verbalized by Prof. Alberto Martini.

Teaching tools

Lectures in class, and laboratory of water, energy and soil mechanics.

Office hours

See the website of Michele Mattetti