BMW M10 Crankshaft
This is a Multi Flexible Body Transient Response Dynamics Finite Element Analysis of the crank piston connecting rod assembly. Below the Von Misses plot at 9000 RPM. This plot shows the maximum stress during the entire simulation. The crank rod piston assembly is simulated from 0 to 13000 RPM.
Shown in red is the RPM of the engine, and shown in blue is the axial displacement of the flywheel on the outer most point. One can clearly see that like most 4 cylinder engines there is a spike right about 4000 to 5000 RPM as well as a spike around 9000 RPM. There is no combustion load nor compression load on the top of the pistons in this simulation, it's just the inertia of the connecting rods and pistons plus a 100 Nm of torque to spin up the crank, that's simulated in this case. A 100000 iterations / steps are made to get a good result for this simulation.
This is a zoomed portion of the same graph right about 9000 RPM where the maximum oscillation occurs
