PSI - Issue 47

Calin-Ioan Birdean et al. / Procedia Structural Integrity 47 (2023) 87–93 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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a)

b)

Fig. 10. Preload stage: (a) stresses in the contact area; (b) bending of bolts.

In order to determine the effect of the access hole for bolt tightening, the RHS part was defined as a continuous element. The results show an increased rigidity of the assembly but similar maximum force, Fig. 11a). The effect of the preload was studied by considering different levels of preload, 50kN, 100kN and 200kN. Only the rigidity of the assembly is affected by the initial preload level, as can be observed in Fig. 11b).

b)

a)

Fig. 11. (a) Influence of the access hole; (b) Influence of the bolt preload.

A major influence on the response of the assembly consists of the thickness of the connection end plate. Initially having the same rigidity, the deformation of the end plate leads to a higher bending in the bolts, thus, a smaller capacity of the connection, Figure 12a). The curve for a plate thickness of 15 mm starts at a higher level because the recordings are given by a top flange point which moves outward of the RHS profile as the bending of the end plate due to the bolt preload is forcing the point to displace. Beside the stress distribution, the rigidity and the maximum capacity of the assembly, the separation of the two RHS profiles is of interest due to aesthetics considerations as the connection should never separate to keep the continuous aspect of an element. The finite element analysis can reproduce the result as observed in Fig. 12b).

b)

a)

Fig. 12. (a) FEM and experiment results. (b) Joint separation in the numerical model.