Hi Daniel
Have been at the 10th HV Mass and Dimension Conference in Paris and have had difficulty with my email - so sorry for the slow response.
"Is the assumption of a rigid beam correct, or should I include an articulation between the cab and the rest of the crane?" By design mobile cranes with their stabilising legs extended have to be very rigid to minimise the flexing that occurs when a load is taken up or put down. and to ensure no indesirable dynamics are set up with the boom at full extension. So assuming the chassis is very rigid would be a good assumption. You refer to the cabin - I suspect you're referring to the cabin plus crane mechanicals and the part of the boom that remains attached to the crane in transport. For the same reasons given above the slewing connection will be very rigid - and in addition in many cranes in travel the boom is supported through a cradle which makes another connection to the chassis.
Hence an assumption of it being a single body without articulation would be supported.
One issue you will face will be getting detailed tyre characteristics - such cranes are usually fitted with tyres that are much larger in diameter and width than those fitted to most road transport vehicles. Keep in mind that the rubber in the tyres exhibits hysteresis so there is an inbuilt though small damping effect there.
And another issue is getting information on the suspension system which may be hydraulic. You'll need to find out the degree to which the hydraulic connections between all the wheels restrict wheel movement at normal travel speeds. This is especially important because at many bridge - road connection points there is a step or short rise or short drop that generates high loads. And these loads can then impact sinusoidally as the crane moves onto the bridge.
Trust this helps
John Lambert
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