I have a requirement to do an FEA on a trailer, where the trailer is being lifted by a crane. The specification calls for a 3-g crane lift (ie, if the crane lifts the trailer with a force of 3 g's, will the wheels fall of when it leaves the ground?) I'm not sure how to model the loads and constraints. Is my best bet to constrain the model at the lift points, and then set a gravity load of 3 g's? Is this possible?
Lyle Beidler MGS Inc 178 Muddy Creek Church Rd Denver PA 17517 717-336-7528 Fax 717-336-0514 <">mailto:-> - <">http://www.mgsincorporated.com> This thread is inactive and closed by the PTC Community Management Team. If you would like to provide a reply and re-open this thread, please notify the moderator and reference the thread. You may also use "Start a topic" button to ask a new question. Please be sure to include what version of the PTC product you are using so another community member knowledgeable about your version may be able to assist.
That is a pretty standard specification. It means that there is acceleration on the lift - i.e. the spooling of the lifting cable is not quasi-static. It also implies a safety factor since the actual acceleration is not known.
I've typically used a constraint (123) at the 'pick point' of the cable and applied a 3-g acceleration profile. You need to make sure your Mass Center of what is being lifted is below the pick point if you are to avoid rigid-body displacement in your simulation. Check your cable loads to make sure they are always in tension.