Identification of elastic properties via (thermo)mechanical testing assisted by digital image correlation

• Grant number: 23/13594-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2023
• End date: November 30, 2024
• Field of knowledge: Engineering - Mechanical Engineering - Mechanics of Solids
• Principal Investigator: Ricardo Afonso Angélico
• Grantee: Arthur Mota Goncalves
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

High-temperature applications usually require refractory materials because of their thermal and physical properties. The mechanical design of structures with these materials demands their elastic properties to be known. Evaluating the elastic properties at high temperatures depends on sensors that generally furnish measurements at a single point of the specimen. Non-intrusive image-based techniques are welcome to overcome this limitation, allowing full-field displacement and strain measurements. Moreover, coupling an experimental system with a numerical approach enables the identification of the above parameters. In this context, the present research project aims to assess the elastic parameters of a refractory material in temperatures varying from room temperature up to 900 °C, combining digital image correlation techniques (DIC) and a finite element model (FEM), thus using a Finite Element Model Updating (FEMU) approach. DIC allows the computation of a full-field displacement measurement in a specific temperature and loading level. Data for the image correlation will be registered via existing apparatus with filters and mirrors to minimize the influence of body irradiation as the temperature increases, and the correlation script will be implemented in MATLAB, with the Correli 3.0 framework. We can model the identification problem using a finite element approach that iterates through various elastic parameters until the computational results match the experimental displacement field (FEMU-U) or the reaction forces (FEMU-F). The model updating will be performed by interacting with Abaqus finite element software. Finally, once the iteration converges to the optimal parameters in the selected temperature range, the two methods will be compared to evaluate the identified elastic parameters. The present methodology may be applied in the future to identify more parameters of the specimen.