A novel updating technique for large finite element models

To obtain reliable and accurate finite elements models, engineers often relay on model updating procedures. These techniques modify the original numerical model on the base of experimentally obtained information, like for example natural frequencies or mode shapes. In most cases, the updating procedures are developed and tested on simplified test structures, where either the dimension of the model or the number of finite elements types are limited to contain the computational costs and elaboration time. Unfortunately, when the same pro- cedures are applied to real industrial cases the updating operations tend to become lengthily and numerically unstable. In this work a novel updating procedure is presented. It consists of two different phases: one devoted to the matching of the natural frequencies between experimental and numerical databases, the second, focused on the matching of the FRFs amplitudes. In both steps, great care has been taken to minimise the computational burden and the operator interference.