Robust improvement of the finite-element-model updating of historical constructions via a new combinative computational algorithm

Finite-element-models are usually employed to simulate the behaviour of historical constructions. However, despite the high complexity of these numerical models, there are always discrepancies between the actual behaviour of the structure and the numerical predictions obtained. In order to improve their performance, an updating process can be implemented. According to this process, the value of the most relevant physical parameters of the model is adjusted to better mimic the actual behaviour of the structure. For this purpose, the actual structural behaviour is usually characterized via its experimental modal properties (natural frequencies and associated vibration modes). For practical engineering applications, the maximum likelihood method is normally considered to cope with this problem, due to its easy implementation together with an understandable interpretation of the updating results. However, the complexity of these numerical models makes unfeasible the practical implementation of the process due to the simulation time required for its computation. In order to shed some light to this problem, a new combinative computational algorithm is proposed herein. Additionally, the performance of the proposal has been assessed successfully via two applications: (i) a validation example, the model updating of a laboratory footbridge, in which the practical implementation of the algorithm has been described in detail; and (ii) a case-study, the model updating of a complex historical construction, in which the main advantage of the proposal has been highlighted, a clear reduction of the simulation time required to solve the updating problem without compromising the accuracy of the solution obtained.