PSI - Issue 40

S.A. Bochkareva et al. / Procedia Structural Integrity 40 (2022) 61–69

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Bochkareva S. A., Panin S. V. / Structural Integrity Procedia 00 (2019) 000 – 000

Fig. 6 – The intensity distribution surfaces for strains (a) and stresses (b) in the ‘PEEK -PEEK prepreg/USW- PEEK’ weld ed joint after tension, as well as the enlarged part of the computational domain (c)

Figure 7, b presents an example similar to that in Figure 7, a but the number of contact points between the interlayer and the plates was three times less. High values of strains were observed at the boundaries, where delamination had occurred, and in contacting nodes, as they were stress and strain raisers. Respectively, the specific load on them increased due to a decrease in their number that accelerated the fracture process.

Fig. 7. – The computational domain of the ‘PEEK -PEEK film- PEEK’ welded lap joint after tension: (a) the number of contact points corresponds to the ideal adhesion; (b) the number of contact points is three times less than in (a); (c) the elastic modulus surfaces

Analysis of the surfaces in the welded lap joint with the PEEK film as an interlayer under tension (Figure 7, c) enabled to conclude that the elastic modulus reduced in these areas primarily due to great strains, since corners of the plates adjacent to the interlayer were the stress and strain raisers. At a high adhesion level, strains propagated from these areas across the plates and formed a neck. The joint fractured through weak points, marked by lines: