PSI - Issue 64

Luigi Granata et al. / Procedia Structural Integrity 64 (2024) 1073–1080 Luigi Granata, Francesco Ascione, Saverio Spadea / Structural Integrity Procedia 00 (2019) 000 – 000

1078

6

⁄ [-] [-]

Table 1. Geometric parameters of the reinforcement.

A WFRP [mm 2 ] 4.28 8.56 12.84 17.12 21.40 25.68

Layer

[mm] 6.11 8.56 9.88 10.70 11.26 11.67

[mm] 0.70 1.00 1.30 1.60 1.90 2.20

[mm 4 ]

[mm] 5.35 5.50 5.65 5.80 5.95 6.10

[mm 4 ]

1 2 3 4 5 6

0.17 0.71 1.81 3.65 6.44

0.18 0.72 1.82 3.69 6.54

0.13 0.18 0.23 0.28 0.32 0.36

1.50 1.51 1.51 1.52 1.52 1.53

10.36

10.56

The material properties are summarised in Table 2.

Table 2. Mechanical properties of fibres and matrix (shear). Fibre Matrix Volumetric fraction , 0,45 0,55 Shear strength (MPa) , 34,0 14-21 Poisson form , 0,29 0,38 Shear module (MPa) , 93023 1159

It is important to remark that is unknown from the experimental programme. Based on the literature, this value should range between 14 and 21 MPa. In this view, this study takes into consideration the minimum, average, and maximum values in the range, which result in the values of the shear strength of the composite reported in Table 3. Table 3. Shear strength of composite S. S [MPa] [MPa] 14,00 10,95 17,50 13,68 21,00 16,42 4. Results and discussion The evaluation of the ultimate value of the load was performed by solving the non-linear problem (Eqs 3a-f) by means of an iterative procedure as described in Figure 3. Step 1: A tentative value of is fixed.  Step 2: Evaluation of ( ) and ( ) by solving (Eqs 3) with boundary conditions (Eqs 4).  Step 3: Evaluation of ( ) by solving Eqn (5c).  Step 4: Evaluation of the section ̅ in which the function ( ) assumes the maximum value.  Step 5: Evaluation of ( ), ( ) and ( ) at ̅.  Step 6: Evaluation of and at ̅ by solving Eqn (11) and Eqn (9),respectively.  Step 7: Failure criterion applied to ( ̅) and ( ̅).The strength values are those of Table 3.  Step 8: If the criterion is equal to 1, is the failure load ( , ).  Step 9: If the criterion is not equal to 1,return to the step 1 changing the value of . Fig. 3. Flowchart of the solving methodology.