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.