Modelling the forced response of a stiffened structure

Different analytical approaches can be used to model the forced response of the beam-stiffened plates or shells that are commonly found in many practical structures from ships to aircraft. A popular method is to smear the mass and stiffness properties of the beam stiffeners to give an orthotropic plate or shell. This is simpler than modelling discrete stiffeners. This paper considers the example problem of a cylindrical shell with ring stiffeners. Previous work using periodic structure theory has shown that the calculated wave propagation behaviour in this cylinder using a smeared shell model is different from that with the stiffeners modelled discretely. The current work calculates the forced response of the cylinder using both models and compares the results to determine the range of applicability of the smeared shell approach.