The experimental load obtention is based on the instrumentation of prototypes and the measurement of the different manoeuvres that need to be known. This methods is quite simple but it has an important limitation: the requirement of an available prototype.
The second method is known as the semi-analytic method. It is based on the determination of the loads through real signals from a previous model and the extrapolation to the components that want to be analysed with dynamic software.
The third method is focused on the determination of the loads through multibody simulation. The great advantage of this method is that it allows us to know the behaviour of all the kinematics points in the model. On the other hand, its main limitation is the complexity of the model and the need of very specific knowledge.