Hello everyone, I am studying the

[Biti Alessandra]

Hello everyone,
I am studying the behavior of a structure under seismic excitation (acceleration record),
Talking advantage of the symmetry, is it ok to model half of the structure only?
my concern is that,
The generated inertial forces under earthquake excitation are related to the mass. And when we model only half of the structure, that means that half of the mass is removed, thus the generated inertial forces will be half the real ones. IS IT logic ?

 

[FEA way]

Symmetry can be dangerous in dynamic analyses. It should be avoided especially in natural frequency extraction simulations since it makes you lose the antisymmetric mode shapes. For this reason, it can also influence the results of analyses relying on modal superposition.