Professor Giuseppe Saccomandi - Constitutive Modeling in Nonlinear Elasticity: History, Pitfalls, and Perspectives

IAS Residential Fellow Professor Giuseppe Saccomandi delivers a seminar on their research - We present a critical overview of constitutive modeling in nonlinear elasticity, with particular emphasis on isotropic incompressible materials. Starting from the historical foundations and the seminal contributions of Rivlin, the talk revisits the motivations behind invariant-based strain-energy functions and their experimental interpretation. The widespread proliferation of constitutive models is discussed in relation to several recurring pitfalls, including over-parameterization, identifiability issues, and an excessive reliance on analyticity. Special attention is devoted to Ogden-type models, whose remarkable descriptive capabilities are contrasted with their well-known limitations in predictive reliability. By reconsidering classical experimental data and multiscale arguments, alternative modeling perspectives are outlined, with the aim of clarifying the principles that should guide constitutive choices in nonlinear elasticity and their applications to soft materials, biomechanics, and wave propagation issues. For more information about the IAS, please visit - https://www.lboro.ac.uk/research/ias