PSI - Issue 18

11

V. Dattoma et al. / Procedia Structural Integrity 18 (2019) 719–730 Author name / Structural Integrity Procedia 00 (2019) 00 –000 Author name / Structural Integrity Procedia 00 (2019) 000–000

729 11

(a) (b) Fig. 14. (a) A xial force/displacement in case of delamination onset; (b) delamination onset. (b) Fig. 14. (a) A xial force/displacement in case of delamination onset; (b) delamination onset. (a)

4.2. Comparison between the models In terms of specimen stiffness in Figure 15a is show that the stiffness in the Model B is greater than that of the Model A (Kaddour and Hinton, 2013). In fact, in the first model the stiffness is 12,250 GPa while in the second model is 13,582 GPa. This result is what we were expected because the layout of the laminae gives more reaction response in the bolted composite joint due to imposed displacements. It was observed that the rivet rotation β is similar for the two models considered; in particular, for model A, the rivet rotation was of 0,368°, while in the model B of 0,356°. Contact pressure was analyzed for both models (Fig. 15b). From the results it was observed that the maximum contact pressure between the rivet shank and the hole surface was 538.67 MPa for model A and 668 MPa for model B. The contact pressure was more evenly distributed for model A compared to model B due to the different rigidity of the edges. Figure 16 show the contact pressure between the head of the rivet and the laminate for two different models. For model A, the maximum pressure was of 119 MPa, while for the model B of 156 MPa. 4.2. Comparison between the models In terms of specimen stiffness in Figure 15a is show that the stiffness in the Model B is greater than that of the Model A (Kaddour and Hinton, 2013). In fact, in the first model the stiffness is 12,250 GPa while in the second model is 13,582 GPa. This result is what we were expected because the layout of the laminae gives more reaction response in the bolted composite joint due to imposed displacements. It was observed that the rivet rotation β is similar for the two models considered; in particular, for model A, the rivet rotation was of 0,368°, while in the model B of 0,356°. Contact pressure was analyzed for both models (Fig. 15b). From the results it was observed that the maximum contact pressure between the rivet shank and the hole surface was 538.67 MPa for model A and 668 MPa for model B. The contact pressure was more evenly distributed for model A compared to model B due to the different rigidity of the edges. Figure 16 show the contact pressure between the head of the rivet and the laminate for two different models. For model A, the maximum pressure was of 119 MPa, while for the model B of 156 MPa.

(a) (b) Fig. 15. (a) Comparison of Bearing stress and strain between Model A and Model B; (b) contact pressure rivet-laminate model B. (b) Fig. 15. (a) Comparison of Bearing stress and strain between Model A and Model B; (b) contact pressure rivet-laminate model B. (a)