Application of digital image correlation to the structural integrity analysis of heterogeneous materials under temperature variation

• Grant number: 17/11389-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2017
• End date: July 06, 2019
• Field of knowledge: Engineering - Mechanical Engineering - Mechanics of Solids
• Principal Investigator: Ricardo Afonso Angélico
• Grantee: Matheus Coelho Gonçalves
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Heterogeneous materials under thermal variation can crack due to mismatch between the thermomechanical properties of its constituents. The difference between the thermal expansion coefficients induces internal stresses which can nucleate cracks on the material when superior to a certain critical value. The literature shows many cases (analytical, computational and experimental) about the mechanisms of nucleation and propagation of cracks in these materials due to thermal variation effects. However, the local effects of the thermal expansion mismatch among the phases can be better investigated using newer experimental methodologies. In this context, the present study aims to analyze the cracks in heterogeneous materials under thermal loads using the digital image correlation technique. This technique allows the visualization and quantification of the displacement and strain fields of the observed sample allowing to analyze the local mechanical behavior. In this project, sample plates will be manufactured with two materials with distinct thermomechanical properties in order to crack the plate when they are exposed to heating/ cooling.A device will be designed and built to perform the proposed experiment, which consists on monitoring the displacement field of a specimen when it is heated by a warm plate. The results of the present study will allow a better comprehension of the fracture mechanisms, mainly in the vicinity of the dispersed phase. Besides that it will provide experimental results that may help on the validation of the computational models that are in development by research group. (AU)