Experimental validation of a topological derivative-based crack growth control method using digital image correlation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guilherme Barros ◽  
João Filho ◽  
Luiz Nunes ◽  
Marcel Xavier

PurposeThe purpose of this paper is to experimentally validate the crack growth control based on the topological derivative of the famous Rice's integral.Design/methodology/approachSingle edge notch tensile specimens with two configurations were tested. Displacement fields near notch were experimentally obtained using the digital image correlation method. These displacements were used to verify the minimization of the associated shape functional, which is defined in terms of the Rice's integral, when a set of controls (holes) positioned according to the topological derivative information, is inserted. Based on the Griffth's energy criterion, this minimization represents an improvement in the fracture toughness of cracked bodies.FindingsThe experimental tests confirmed that a decrease around 27% in the value of the associated shape functional can be obtained following this approach. Therefore, the results allow us to conclude that the predictive methodology for crack growth control based on the topological derivative is feasible.Originality/valueThis is the first work concerning experimental validation of crack growth control based on the topological derivative method.

2014 ◽  
Vol 611 ◽  
pp. 490-495
Author(s):  
Martin Schrötter ◽  
Martin Hagara ◽  
Matúš Kalina

The aim of this article is to present the influence of stochastic pattern on results accuracy of digital image correlation method in plastic areas. The various types of stochastic patterns were applied on testing specimens which were then tensioned. There was correlated the intensity of black and white color (denoted as grey value) dispersed on a specimen, then the mean value of estimated error for unloaded state as well as state of highest measured deformation and finally the amount of non-correlated facets. Also the maximal deformation of specimens was compared by which the damage of stochastic pattern emerged.


2010 ◽  
Vol 1 (4) ◽  
pp. 344-357 ◽  
Author(s):  
V. Richter‐Trummer ◽  
P.M.G.P. Moreira ◽  
S.D. Pastrama ◽  
M.A.P. Vaz ◽  
P.M.S.T. de Castro

PurposeThe purpose of this paper is to develop a methodology for in situ stress intensity factor (SIF) determination that can be used for the analysis of cracked structures. The technique is based on digital image correlation (DIC) combined with an overdetermined algorithm.Design/methodology/approachThe linear overdeterministic algorithm for calculating the SIF based on stress values around the crack tip is applied to a strain field obtained by DIC.FindingsAs long as the image quality is sufficiently high, a good accuracy can be obtained for the measured SIF. The crack tip can be automatically detected based on the same strain field. The use of the strain field instead of the displacement field, eliminates problems related to the rigid body motion of the analysed structure.Practical implicationsIn future works, based on the applied techniques, the SIF of complex cracked plane stress structures can be accurately determined in real engineering applications.Originality/valueThe paper demonstrates application of known techniques, refined for other applications, also the use of stress field for SIF overdeterministic calculations.


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