This study presents an approach to determine strain-stress curves of printed PLA material using 2D Digital Image Correlation (DIC) method. Besides, the present paper is an extended version of the previous study of the authors [1]. The tensile specimens were printed with a constant infill ratio and performed uniaxial tensile test with various test speeds. The elongations and local strains were measured with 2D DIC. Stress vs. strain curves were calculated from force data and DIC measurement. As a result, ultimate tensile stresses were directly proportional with the test speed increments, and maximum forces as well. The elongations were observed to decline during the test speed increments. It was underlined that the elongations gave the average results instead of the real behavior of the fractured area.

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This study focused on the formability of aluminium alloy (7075-T6) sheets through hydroforming route. Formability of these sheets was tested using a warm forming setup at three different temperatures and four different die corner radii. Forming limit diagrams (FLD) were generated by measuring the grids of the sheet formed. The results show that the forming limit of AA7075-T6 can be significantly improved when the blank was heated to 140-250 • C. It was also observed that as the temperature increases above 140 • C, dome height began to decrease. Also the results indicated that both the die corner radius and temperature have a significant effect on the stress-strain curve and warm forming of AA7075-T6 sheets. Thus, with the temperature increased from room temperature (RT) to 140 • C, the flow stress decreased and the strain increased, hence, the formability is enhanced. However, further increase in temperature causes decreases the flow stress and strain. Similar changes of the flow curve were seen in die corner radius. Decreasing the die corner radius decreases the flow stress and increase the strain. Moreover, an equation was obtained by establishing correlations between the experimental parameters and their results. In this way, it became possible to make predictions.