Experimental and Numerical Analysis of the Stress State Produced by a Circular Hole Concentrator

Abstract

The paper proposes the analysis of strain and stress state, through experimental and numerical means, of a circular hole type concentrator. The strain state is analyzed through the microscopic Digital Image Correlation technique, due to the small scale of the samples, whose calibrated region is 10x8 mm. The numerical analysis is conducted using the Finite Element Method, through a static structural analysis, using a linear-elastic material model. The results from the two procedures are compared by means of strain field distribution around the stress concentrator and stress variation at the concentrator peak cross section. For validation, the analytical gross stress concentrator of the problem is used as baseline, Ktg. The results show that accurate reading can be achieved on this small scale. Additionally, the experimental method has also successfully identified crack initiations and propagations on the tested samples, significantly smaller than 1 mm, which can reveal future fracture mechanics analysis and supply data to models adapted to microscopic scale phenomena.