Issue 68

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

the impossibility of delamination), the fracture process was caused by initiation and propagation of cracks in the PEI adherends. Fig. 10, b and c shows distributions of the maximum strains at ideal adhesion, while Fig. 10, a and b visualizes bending of the PEI adherends due to the Poisson effect. In this case, both the prepreg and the top PEI plate were practically not compressed. This fact gave rise to large strains of the bottom PEI adherend at the corners of the USW lap-joint, where the fracture process began. At an adhesion level of 30 MPa and above, failure occurred due to initiation and propagation of cracks in the PEI plates, as with ideal adhesion. In the latter cases, plastic strains were higher than those at the minimum adhesion level of 5 MPa.

Figure 8: The strain–stress diagrams for the USW lap-joints at the adhesion levels from 5 up to 60 MPa.

a)

b)

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