PSI - Issue 51

Mohammed Algarni et al. / Procedia Structural Integrity 51 (2023) 185–191 M. Algarni/ Structural Integrity Procedia 00 (2022) 000–000

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( right ). Using the model, the highest possible strain value at fracture is 2.55% with an optimized set of process parameters of RSA = 90º, LYT = 0.24 mm, and IFD = 65%. �%� � ����� � � ���� � � ����� � � ������ � � ����LYT� � � ���������� � (2) 3.3. Modeling Validation The modeling prediction results are compared to the experimental results are expressed in table 1 and displayed in Fig. 2 ( left & right ). The tensile strength prediction error ranges from 0.3% to 6.1%, with an average of 3.6%. This is shown in Fig. 3 ( left ), where the green triangles are the predicted strengths that are bounded between the upper (dashed in red line) and lower (dashed line in blue) error boundaries of ± 6.1%. Similarly, the strain at fracture prediction error ranges from 0.8% to 4.2%, with an average of 1.2%. In Fig. 3 ( right ), the predicted strain at fracture in green triangles is bounded between ± 4.2%. Consequently, both mathematical models are reliable for mechanical properties prediction with low deviation.

Fig. 3. The modeling results in green triangles are the tensile strength ( left ) and strain at fracture ( right ) bounded between two dashed lines representing the error % boundaries. 4. Parametric Study 4.1. Effect of RSA on the mechanical behavior During the experiments, the tensile strength and strain at fracture were recorded for each combination of process parameters. The input process parameters selected are RSA, LYT, and IFD, as shown in table 1. Three RSAs were selected: 0°, 45°, and 90°. It was noticed that for specimens with 0°, RSA had the maximum tensile strength, and as the RSA increased, the specimens weakened. In Fig. 4 ( left ), the average tensile strength for specimens with RSA 0° is 797 N. This average tensile strength decreases by 21% to become 630 N on average for specimens with RSA 45°. The tensile strength average decreased by 39% to become 481 N on average for specimens with RSA 90°. This is because the layers parallel to the loading direction provide more resistance to fracture, which causes higher tensile strength. On the contrary, the strain at fracture increases as the RSA increase, as shown in Fig. 4 ( right ). The average strain at fracture for all specimens with RSA 0° is 1.55%. Strain at fracture increases by 18% on average to become 2.04% for specimens with RSA equal to 45°. Furthermore, specimens with RSA 90° have the highest strain at fracture, averaging 2.31%. This increase might be due to the role of diffusion between the layers. The analyses show that RSA significantly influences the strength and strain at the point of fracture. 4.2. Effect of LYT on the mechanical behavior In the same vein, three LYT’s were selected: 0.1mm, 0.2mm, and 0.3mm. It was noticed that specimens with 0.3mm LYT had the maximum tensile strength and as the LYT decreases, the specimens weaken. In Fig. 5 ( left ), the average tensile strength for specimens with RSA 0.1mm is 577N. This average tensile strength increases by 10% to become 629N on average for specimens with LYT of 0.2mm. The tensile strength average increases more by 22% to become 702N on average for specimens with LYT 0.3mm. This is due to layers with thicker thicknesses exerts more