Identificazione di un modello di ordine ridotto per il calcolo in tempo reale delle tensioni termiche

In mechanical and aeronautical applications characterised by high safety requirements and expensive maintenance costs, systems for on-line calculation of thermal fatigue damage are widespread. In those systems a methodology widely used for thermal stress calculation is the Green's Function Technique (GFT). In this paper a low-order model is proposed, able to replace the GFT in thermal stress calculation. The convolution integrals which characterise the GFT are converted in a system of first order differential equations. The model's coefficients are identified by means of the Prony method. The methodology is applied to two study cases; results show that the precision of the low order model is comparable to the GFT and that the number of operations per time unit is significantly reduced.