Applicability of colour transfer techniques in Twelve fringe photoelasticity (TFP)

Extraction of Fracture Mechanics Parameters From Fem Analysis: Algorithms and Procedures

“…The minimum number of stress tensor components was 219 since one can use the only circle with the following stress tensor components σ 11 , σ 12 , σ 22 . Increasing the number of considered concentric circles surrounding the crack tip one can enhance the dimension of the system (5). The maximum number of equations in (5) in the numerical experiments performed was 3492 from which the first fifteen coefficients of WE have been obtained.…”

“…Defects and cracks play a decisive role in characterizing the strength and failure of these materials and structures [1][2][3][4][5]. Therefore, gaining insight on cracking processes is of crucial importance [1].…”

“…Therefore, gaining insight on cracking processes is of crucial importance [1]. The first step in analyzing any fracturing process is to determine the crack tip asymptotic fields in order to characterize the stress, deformation and displacement near the crack tip, which requires the coefficients (unknowns) of the crack tip asymptotic field to be determined via reliable methods [1][2][3][4][5][6][7][8][9][10]. The first terms of the crack tip stress series expansion in isotropic linear elastic materials are singular, and, hence, dominant, in the proximate vicinity of the crack tip.…”

Analysis of the Stress Field in Photoelasticity Used to Evaluate the Residual Stresses of a Plastic Injection-Molded Part

“…In principle, digital photoelasticity takes advantage of the fact that birefringent bodies can reveal stress information through color fringe patterns; therefore, it is necessary to demodulate the information in the images to quantify stress. In this field of study, new computational developments have favored the transition from conventional techniques based on manual quantification of color fringe patterns to computational technologies based on image processing by means of polarization states, quantification of light intensity [ 1 , 2 ], and determination of phase delay through unwrapping strategies [ 2 , 3 , 4 , 5 ]. Such analyses have been performed on bodies made of different types of birefringent materials; notwithstanding, translucent polymers have been more popular because their optical properties have been deeply studied.…”

“…However, residual stresses have a negative effect on the optical properties required for these developments [ 6 , 7 ], as well as on the expected mechanical performance of plastic parts [ 8 , 9 ]. For this reason, numerous studies have been published on the reduction of residual stresses in polycarbonate parts [ 1 , 10 , 11 ]. In this sense, computer simulations have contributed to the analysis and prediction of residual stresses in injected parts.…”