PSI - Issue 57

Philipp Ladendorf et al. / Procedia Structural Integrity 57 (2024) 589–597 Ladendorf, Herion, Winkler, Dürr / Structural Integrity Procedia 00 (2019) 000 – 000

594

6

Fig. 6. Percental de iation of gusset-plate SCF from con entional K-joint SCF

3.2.4. SCF-reduction compared to fabrication effort The economic fabrication of hollow section joints is always one of the most important arguments when it comes to decisions for specific construction-designs. Although it is ob ious that these in estigated gusset-plate ariants lead to higher fabrication efforts compared to con entional hollow section K-joints, the pre-cut slots facilitate the exact align ment before welding. Since the designer needs to ha e a guidance concerning the fabrication effort of the in estigated ariants in comparison to the achie able SCF-reduction, the geometry-dependent, expected fatigue strength classes will be rated against the manufacturing efforts by introducing the connections lengths l A of all in estigated geometries and ariants. As example, Fig. 7 shows the connection length for a con entional K-joint as well as for ariant 2. As simplification, section- and weld-seam-radii are neglected and only the length of the connecting areas is accounted for. Assuming the required weld-seam-thickness is the same for one specific geometry, the results can be compared to one another. The connection lengths l A of the gusset-plate ariants are scaled to the con entional K-joints into the parameter ‘scaled relati e connection length’ Λ. This parameter Λ is also used for the right -hand ordinates in Fig. 8, where the left-hand ordinates show the calcu lated geometry-dependent fatigue strengths by using the numerically determined SCF and the fatigue-life-estimation formulae of DG8 for 2 × 10 6 load-cycles. For the calculation, also numerically determined SCF smaller than 2.0 ha e been used (cp. Fig. 5). Since there is a great ariety of the in estigated geometries and ariants, Fig. 8 presents the minimum and maximum fatigue strengths at the brace-Hot-Spot (H.S.) for the load-case AX as ho ering columns and Λ as connecting line with the in estigated geometrical range as er ror bars.