These slides were presented at the NAFEMS World Congress 2025, held in Salzburg, Austria from May 19–22, 2025.

Abstract

The accurate calibration of materials models is crucial for simulating the behavior of materials across various industries, including automotive, aerospace, and consumer goods. With the increasing complexity of modern materials, particularly polymers, foams, and composite materials, developing reliable and efficient calibration strategies is more important than ever. This paper presents a comprehensive comparative analysis of calibration strategies for material models applied to these materials, focusing on the challenges and best practices for each material class. The study explores the calibration and validation of three specific models: the Fu Chang model for foams, the SAMP model for polymers, and composite damage models for continuous fiber-reinforced thermoplastic composites (CFRTPs). The research integrates experimental testing campaigns, such as tensile, shear, compression, and impact tests, under varying strain rates and environmental conditions, to collect detailed data that are essential for effective model fitting. For polymers, the semi-analytical SAMP model is calibrated using a combination of advanced testing techniques, including high-speed video analysis and digital image correlation (DIC), along with optimization algorithms. This approach allows for the precise characterization of strain-rate dependencies and the evolution of damage under different loading conditions. In foams, the calibration process focuses on the accurate representation of stress-strain curves and material rate sensitivity, providing valuable insight into robust calibration practices that account for dynamic loading and high-strain-rate phenomena. For CFRTPs, the study addresses material modeling at both macro and meso scales. At the laminate level, the study emphasizes the modeling of nonlinear behavior, including strain-rate effects, making the material models suitable for impact applications. At the lamina level, calibration highlights the importance of fiber orientation and interface modeling, which significantly influence the material's performance under complex loading conditions. This paper highlights the unique challenges posed by each material class, including strain-rate sensitivity, failure evolution, and the complexities involved in multi-scale modeling. It also discusses the importance of flexible calibration workflows that can adapt to different material behaviors and loading scenarios. The integration of advanced optimization tools is crucial for achieving reliable predictions in dynamic applications after the calibration process. The findings of this research offer valuable insights into the optimization of calibration strategies and provide practical guidance for selecting the most suitable fitting processes.