Issue 68

V. O. Alexenko et alii, Frattura ed Integrità Strutturale, 68 (2024) 390-409; DOI: 10.3221/IGF-ESIS.68.26

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b) Figure 12: The USW joint thinning vs USW duration dependences.

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Δ  CF ,  m

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b) Figure 13: The ‘CF-fabric layer’ thickness vs USW duration dependences.

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Figure 14: The integral prepreg characteristics vs the USW durations and the prepreg thicknesses.

M ANUFACTURE OF LAMINATES BY USW

or continuing the discussion of the obtained results and confirming the possibility of fabricating laminates by the USW procedures, the authors compared the mechanical properties of ones made by compression molding (CM) and the USW technique. The evaluation was based on the results of the conventional short beam interlaminar shear test for laminates (ISO 14130:1997). In the fabrication of a sample by the CM method, the prepreg with the PEI/CF-fabric ratio of 43/57 wt.% was used. Upon the CM process, seven layers of the prepreg laid in a stack were compressed at a pressure of 0.5 MPa and a temperature of 320  C. In the USW procedure, the parameters determined in the previous section were implemented: the USW duration of 520 ms, the PEI/CF-fabric ration of 23/77 (which approximately corresponded to the middle of the green area in Fig. 14). As in F

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