This study investigates the modelling of constitutive laws of materials by
neural networks. Material behaviour is no longer represented mathematically
but is described by neuronal modelling. The main aim is to build a neural
network directly from experimental results (the learning phase). We give se
veral examples of constitutive laws (Hooke, Sargin, etc.) using a backpropa
gation algorithm. Then we show that abilities of adjustment, memorisation a
nd anticipation of neural networks permit us to develop a method of classif
ication of constitutive laws. (C) 1999 Elsevier Science Ltd. All rights res
erved.