BMW Motorrad is the motorcycle division of BMW, a German multinational companymanufacturing luxury automobiles and motorcycles. With the first motorcycle manufactured in 1923, their current product line includes a variety of shaft, chain, and belt-driven models designed for off-road, dual-purpose, and sports powered by a variety of engines ranging from a single cylinder, various two cylinder (parallel twin, flat twin, boxer etc.), four cylinders inline and six-cylinder inline ones.
Crankshaft Model Building
Crankshaft model building for BMW was previously outsourced to external providers with average time taken for a model being between 1-2 weeks depending on the engine type. Established procedures at the organization require an annual estimate of new crankshaft models to be produced, based upon which budgetary decisions can be made. Often, actual production of the number of models would fall short of estimates due to varying constraints on the part of the suppliers. In addition, for any additional crankshaft models when required, overall order processing time could take long. To facilitate effective budgetary planning and decision-making, accuracy in model production forecasts with a high degree of confidence became necessary. Based on a recommendation from an employee having worked with Altair SimLab at another facility, the group at BMW chose Altair as a development partner in order to explore alternate solutions.
Automating Crankshaft Modeling for BMW Motorrad using Altair SimLab
The initial, preferred course of action for the first project was to clone the classical approach. This entailed duplicating a previous vendor’s process and building the model without using all
the SimLab features. In parallel however, Altair engineers developed the same model using SimLab technology and then demonstrated the process to BMW. As motorcycle crankshaft simulation uses a detailed FE-mesh for structural and fatigue analysis, due to long time durations for FE meshing, the idea was to establish a process to BMW. As motorcycle crankshaft simulation uses a detailed FE-mesh for structural and fatigue analysis, due to long time durations for FE meshing, the idea was to establish a process for automated crankshaft meshing in SimLab. With the second project, the classical process was migrated to a complete SimLab process. The semi-automated process applied by BMW Motorrad to model an engine crankshaft for structural and fatigue analysis using SimLab includes the following steps:
- Group assignment
- Mesh controls & surface mesh
- Layered elements, volume mesh & RBEs
- Renumbering and group set definition
The comparison tools inside SimLab identify the difference between the current model and a new variant, and help to transfer the group structure from the current model to the new variant with very little user interaction to update the groups. The group structure is the basis of the overall automated process.
Using the SimLab process has reduced model creation time for BMW by about 80%. For the 4-cyclinder, the user interaction process that previously took about an hour, has now reduced to 5-10 minutes using SimLab. Time to build a first new model has been reduced to about half a day and for consecutive variations to about an hour.