Effect of subset parameters selection on the estimation of mode-I stress intensity factor in a cracked PMMA specimen using digital image correlation

On the Deformation Analysis during RCSR Process Aided by Finite Element Modeling and Digital Image Correlation

“…Homogeneous microstructure, large induced 24 strains, minimum dimensional changes, and potential for 25 industrial applications are the factors that should be 26 considered in the design of these processes. [1][2][3] 27 Equal channel angular pressing (ECAP), [4][5][6][7][8] high-pressure 28 torsion (HPT), [9,10] accumulative roll-bonding (ARB), [11,12] 29 repetitive corrugation and straightening (RCS), [13][14][15] con- 30 strained groove pressing (CGP), [16][17][18] and constrained groove 1 rolling (CGR), [18] are the primary techniques used in the 2 production of ultrafine grained metals. 3 Nearly, all these methods satisfy the main SPD require-4 ments but also have some shortcomings which do not 5 encompass all the mentioned design factors.…”

“…[20] Edge 27 cracks are frequently observed and the thickness reduction of 28 the strip can be inhomogeneous. [21] Techniques such as RCS 29 which rely upon repetitive bending and straightening of a 30 sheet does not produce enough plastic strain per cycle for 31 effective grain refinement prior to the formation and growth 1 of fatigue cracks. [13,22] In groove pressing methods, plastic 2 strain is lower at the local interface between the shear and 3 flat regions and strain localization is more intensified with 4 the number of cycles although the average strain level 5 increases.…”

“…27 The aims of the new design are the fabrication of UFG materials 28 by imposing more severe strain, minimal dimensional changes, 29 the ease of process and industrial applicability. 30 Understanding deformation mode in RCSR helps to design 31 process parameters to optimize the deformation itself and 32 this would lead to an optimal condition 33 that results in a sample with minimum 34 dimensional change. This study aims to 35 comprehensively analyze the deformation 36 mode in RCSR and derives the optimal 37 condition for the process.…”

“…In the final design, the 27 corrugations have an elliptical shape. 28 For the mentioned corrugation radius of curvature with the 29 sample's thickness of 4 and 10 mm, and rollers gap equal to 30 these thicknesses and t þ 3, t þ 5, and t þ 8 (mm), strain 1 analysis using Abaqus software were done for the first step of 2 one RCSR cycle. As an example and for brevity, the results for 3 one of these conditions (sample thickness and rollers gap 4 equal to 10 mm) are shown in Figure 2.…”

“…The designed model is shown in Figure 3b. In 29 this model both rollers are considered to be discrete rigid and 30 the sample was chosen to be deformable and material was 31 modeled as simple elastic-plastic one. Elastic and physical 32 properties used in this simulation are shown in Table 1 Digital Image Correlation (DIC) is a state of art technique 5 that can be used for precise strain measurement.…”