The World Solar Challenge began as one man's adventure to cross Australia in a homemade solar car more than a quarter of a century ago. That single intrepid and pioneering experiment has evolved into the world's leading solar vehicle expedition across a landscape that is as remarkable as the vehicles that traverse it.

Abaqus was used to virtually test the structural integrity of the aluminium chassis. Initial sizing for the frame was done using a simple truss analysis with loading and boundary condition assumptions used. A beam model was run to test several static and dynamic load-cases to represent the worst case loading conditions.

The challenge will have 38 solar cars and teams from 17 countries racing across 3,000km of the Australian outback from Darwin in the Northern Territory, to Adelaide in South Australia. It will take the teams a week to complete the journey, travelling the length of the infamous Stuart Highway.

Cambridge Universitys launched their solar car entry, the Endeavor, at this years legendary Goodwood Festival of Speed event at Lord Marchs estate in West Sussex. Brawn GP's Formula 1 star and new world champion, Jenson Button was on hand to help officially launch the solar racer.

Button talked to members of the CUER team and signed the car, commenting: "There's some very impressive technology in this racing car. It may be a world away from an F1 car in terms of power, but to get a car to drive at 60mph using 2 horsepower takes cutting-edge engineering."

Cambridge University Eco Racing Team
The story of Cambridge University Eco Racing (CUER) team does not start at the Goodwood Festival. The preceding two years has been made up of a lot of planning, hard work, and engineering. Dassault Systemes has provided the team with the tools required to design and realistically simulate the entire car before the team even picked up a screwdriver. Using Dassault Systemes' 3D technology to design the car and SIMULIAs Abaqus Finite Element Analysis (FEA) for the simulation gave the team a winning combination of software to get the job done.

Vehicle Design
The solar powered class of vehicles is unique in that they have the ability to generate its own power using energy from the sun. This theoretically gives the car an infinite range owed to its very efficient electrical system which utilizes the 6m2 solar array. In order to get the best performance from the battery, the engineering team is challenged to find the best aerodynamic design which will reduce rolling resistance, drag, and overall weight.

With this in mind, the aluminium space-frame, on top of which the carbon fibre composite shell sits, has been designed to be as light weight as possible. At the recent SIMULIA Academic Forum in Cambridge, Kento Taoka, who designed the composite body of the car said, Dassault Systemes' 3D technology was used for the overall car design. We have chosen a three wheeled tricycle configuration to reduce mass and simplify the drive-train.

Energy consumption is also of prime consideration to the car design. Calculations show that of the 1320W available to the solar cells, 260W is lost due to the curved solar cell array not being fully efficient. A further 680W will be consumed by aerodynamic drag despite it having a drag coefficient of 0.1 (compared to 0.6 of a Toyota Prius). This means that the remainder of the vehicle must be optimised to be as structurally efficient as possible.

Losing Weight with FEA
Abaqus was used to virtually test the structural integrity of the aluminium chassis. Initial sizing for the frame was done using a simple truss analysis with loading and boundary condition assumptions used. A beam model was run to test several static and dynamic load-cases to represent the worst case loading conditions. This gave a good indication of the global response of the structure. Further to the beam analysis, a shell model was developed to check the local plastic response of the joints surrounding the roll-bar should the vehicle roll over. The results of the simulation helped design the space frame 7kg lighter than the prototype. Mass savings are crucial to make the car as efficient as possible.

Weight was not only saved in the cars chassis but in the outer shell of the vehicle too. The shell is constructed of a carbon-fibre weave either side of a honeycomb core. The composite layup tool in Abaqus was used to define a 3 ply stack verifying the structure was strong enough to support the loads required. The shell defines the aerodynamically efficient shape of the vehicle, as well as the surface area for the solar cells.

Australian Endeavour
Driving the car itself will be tough, with temperatures in the outback regularly being above 40 degrees Celsius. With no air conditioning and virtually no fresh air in the cockpit drivers are limited to a 4 hour stint in the car. The lightweight design however should help the team maximise the speed of the car and, therefore, the distance it covers for every stint.

As the team prepares for the final stint of their preparations, Kento also added, there are about 30 cars entering and we are hoping for a top ten finish.

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