City bus crash using LS-DYNA

[albercelta]

Dear all,

I am trying to model a city bus crashing againt a rigidwall. The bus has been modelled, mainly, using beam elements.

THE PROBLEM: During the first part of the simulation everything seems to be perfect. The front structure beams are deformed during the crash.

In the simulation, when the failure strain of one beam is reached, the element is deleted, as expected.

The problem appear when the failure strain is also reached in an adyacent beam. At this moment, the node situated between the both beams that have failed is deleted and the simulation stop working properly. Simulation is still running but the contact between the rigidwall and the bus does not work any longer.

Anyone have any idea about why contact stop working when a node is deleted? (i know it happened when a node is deleted because i repeated a simular simulation using shells elementos and the result is the same)

Thank you very much for your time, and sorry for writing so much, but i have tried to explain it in the best possible way.

 

[Drej]

My initial concern would be validating the approach of using beams to model the bus - how have you validated this representation? Surely shells or solids (or a hybrid structure with shells/solids/beams) would be a better choice?


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