Design Optimization of a Scooter Main Stand to Improve Durability of Its Crankcase Support 2016-01-2341
When a scooter is put on main stand, it keeps the vehicle from falling as it rests against the engine crankcase. As the main stand is operated it transmits a large amount of load to the crankcase, thus creating a necessity to check the durability of the later. Practical tests showed that continuous application of the main stand resulted in the failure of its pivot area on the crankcase. This raised questions not just on the feasibility of the crankcase design in terms of durability, but also on the main stand design in terms of a load transmitting member. However, as the project was at its later stage, crankcase design could not be altered; thus it asked for a main stand design optimization.
The base main stand model was thus taken for MBD simulation and loads were generated for further FEA analysis. The meshed crankcase model was taken in a commercially available FEA code for checking its durability. Accurate constraints and boundary conditions were applied close to the crankcase’s main stand resting area to replicate real time environment. Loads obtained from MBD simulation were applied in the form of amplitudes to build a quasi-static FEA model. The results showed more stress and less fatigue cycles in the localized main stand support area of the crankcase. It called for a judicial main stand design optimization without largely affecting the styling or cost.
The design of the main stand was altered in such a way that now the load on the crankcase was transmitted in a manner which is more evenly distributed. In a similar way as mentioned above, MBD simulation was done to extract the loads for the new main stand design. Using similar boundary conditions and updated loads, the crankcase was simulated. Stress was found to have significantly reduced and fatigue cycles improved significantly. The new design was tested and no crankcase failure was observed.