Identification of cohesive law for refractory materials by Digital Image Correlation combined with Finite Element Method

• Grant number: 17/20911-9
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: March 01, 2018
• End date: August 31, 2018
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Rodrigo Bresciani Canto
• Grantee: Rafael Vargas Maginador
• Supervisor: Francois Hild
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Institution abroad: Laboratoire de Mécanique et Technologie (LMT Cachan), France
• Associated to the scholarship: 17/05678-6 - Finite element methods and digital image correlation applied on the wedge splitting test analysis, BP.MS

Abstract

High temperature and corrosive environments in which castable refractories are applied involves high risks. In this context, the characterization of these materials becomes extremely important, and an essential tool for the correct selection, application, development and research in that area. However, there are some difficulties identifying the Fracture Process Zone (FPZ), i.e., an energy dissipation region near the crack tip caused by the interaction between the propagating crack and the underlying microstructure. One way of FPZ identification is using Digital Image Correlation (DIC) to compare displacement fields with Finite Element (FE) simulations. In this internship project it is proposed to obtain the parameters of the Cohesive Zone (CZ) model via FE simulations of refractory fracture using DIC data on the Wedge Splitting Test (WST). The displacement field is experimentally measured with 2D-DIC and its borders used as boundary conditions for the FE model. The measured displacement field is then compared with the simulation results to extract the CZ parameters as minimizers of the chi-squared norm of the difference between measured and simulated displacement fields. This methodology will be used to obtain CZ parameters that match as best as possible the experimental results with computer simulations. The FPZ would then be measurable from cohesive element damage, and computer simulations would consider the wake effects given by energy dissipation mechanisms, e.g., mechanical union of aggregates after cracking, crack branching and microcracking. If time allows, similar procedures on more complex geometries will be tested in order to measure 3D damage from images taken from both side of WST specimen.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

VARGAS, R.; NEGGERS, J.; CANTO, R. B.; RODRIGUES, J. A.; HILD, F.. Comparison of two full-field identification methods for the wedge splitting test on a refractory. Journal of the European Ceramic Society, v. 38, n. 16, p. 5569-5579, DEC 2018. (17/20911-9)

VARGAS, R.; NEGGERS, J.; CANTO, R. B.; RODRIGUES, J. A.; HILD, F.. Analysis of a tastable refractory using the wedge splitting test and cohesive zone model. Journal of the European Ceramic Society, v. 39, n. 13, p. 3903-3914, OCT 2019. (17/20911-9)

VARGAS, R.; NEGGERS, J.; CANTO, R. B.; RODRIGUES, J. A.; HILD, F.. Analysis of a castable refractory using the wedge splitting test and cohesive zone model. Journal of the European Ceramic Society, v. 39, n. 13, p. 12-pg., 2019-10-01. (17/20911-9)