An Inverse Model Reduction Method for Finite Element Model Updating in Structural Health Monitoring

Abstract

Model-based structural health monitoring using an updating scheme can detect, localise and quantify
damage. The model updating is achieved by means of numerical optimisation, which requires a large
number of finite element simulations to achieve convergence. The computational cost of this process can
be lowered by reducing complex finite element models to numerically more efficient representations.
In wind energy, slender shell structures like the tower structure and the wind turbine rotor blades are
reduced to beam models for structural mechanics computations. The usual way to obtain distributed beam
properties is to extract axial stiffness parameters as well as moments of inertia for several cross-sections
along the length of the considered structure. This can be achieved analytically or by two-dimensional finite
element calculations. In case of widely varying cross-sectional properties, the discretisation along the
longitudinal axis of the structure has to be very fine in order to accurately represent its global behaviour.