The concept and the embodiment design of a frame for a race motorcycle is addressed. The motorcycle is designed for the Moto3 World Championship. The aim is to develop a frame that could be eventually produced by die casting.
Given the basic geometry of the motorcycle and the engine dimensions, a multi-body model is derived by Modelica. The model is able to simulate the dynamic behaviour of the motorcycle in the two most critical conditions of use, namely braking and passing over a cleat. A comparison with experimental data has allowed the validation of the model.
By means of Optistruct, an optimized structure for the frame is proposed and compared to the one derived by an experienced designer. A technique is proposed for the computation of stresses in the frame that exploits, in an integrated manner, FEM and multi-body modeling. A fatigue analysis aimed at assessing the life of the frame is performed.
The combination of the most advanced modeling tools has enabled the design of a very light and stiff frame, additionally a process has been derived for future development of optimised motorcycle frames.