A beam to 3D model switch in transient dynamic analysis

• Use of a 3D model and a beam model at two different stages of the same computation.
• For dynamic problems with non-linearities restricted in space and time.
• The switch reduces considerably the computational cost with preserved accuracy.
• Two different initialization techniques are investigated.
• The energy consistency of the switch is demonstrated.

Transient structural dynamic analyses often exhibit different phases, which enable one to use an adaptive modeling. Thus, a 3D model is required for a better understanding of local or non-linear effects, whereas a simplified beam model is sufficient for simulating the linear phenomena occurring for a long period of time.This paper proposes a method which enables one to switch from a beam to a 3D model during a transient dynamic analysis, and thus, allows one to reduce the computational cost while preserving a good accuracy.The method is validated through comparisons with a 3D reference solution computed during all the simulation.