Determination of Complex Modulus from a Back-Analysis Process of Frequency Response Functions for Asphalt Mixtures Using FEM Modeling

This paper presents a method to determine the complex modulus of asphalt mixtures (AM) from Frequency Response Functions (FRFs) using a back-analysis approach. The main objective was to optimize the process for obtaining the linear viscoelastic (LVE) properties of AM based on non-destructive impact resonance test (IRT) data. The methodology combines an optimization code developed in MATLAB with numerical simulations in COMSOL, using the Finite Element Method (FEM) in 2D and the 2S2P1D rheological model to simulate the LVE behavior. The combined use of MATLAB and COMSOL allowed for efficient integration between numerical simulation and the optimization process, resulting in a more robust and automated methodology for analyzing viscoelastic materials. The results obtained from the IRT were compared with those from the Tension-Compression test (TCT). A good agreement was observed between the results of both tests, demonstrating the effectiveness of the proposed method. The expected impact of this research is to contribute to the advancement of computational tools for material characterization in engineering, with potential applications in road infrastructure projects and other related fields.