PSI - Issue 44

Marius Pinkawa et al. / Procedia Structural Integrity 44 (2023) 2342–2349 Marius Pinkawa, Cristian Vulcu, Benno Hoffmeister / Structural Integrity Procedia 00 (2022) 000–000

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In general, the case studies performed well for the given seismic loading. Uprights and braces are in general not overstressed for all the case studies. If this is however the case, the utilization ratio is only slightly larger than 1 and this overstress is only existent in very few spots. Moreover, this is caused by MNV-Interaction, which was evaluated conservatively by adding up the single utilization ratios due to axial forces, shear forces and bending moments, i.e. E d /R d = N Ed /N Rd + V Ed /V Rd + M Ed /M Rd . A more rigorous evaluation could lead to utilization ratios smaller than 1.0 in the very few cases of upright overstress.

Table 1. Utilization ratios of key structural components. Key component CS-1

CS-2 0.89 0.56 0.89 0.66 0.66 0.25

CS-3 0.71 0.71 0.63 0.52 0.52 0.25

CS-4 1.07 0.94 1.07 0.78 0.78 0.44

CS-5 0.91 0.58 0.91 0.67 0.67 0.67

Uprights

0.85 - - 0.95 - - 0.76 0.19 - -

 Member stability  Cross section  Member stability  Cross section

Diagonal braces

1.27 t=5mm 3.18 t=2mm

Connections: Braces to upright

0.60 0.06 0.06 ≈ 0 1.10 0.15 0.47 1.10 -

0.63 0.32 0.32 0.31 0.83 0.32 0.17 0.15 0.32

1.06 3.60 ≈ 0 3.60 0.59 0.59 0.37 0.53 -

Spacer

1.08 ≈ 0 1.08 0.69 0.69 0.54 0.60 -

 Member stability  Cross section  Spacer Connection

-

Roof truss

 Braces  Upper chord  Lower chord

-

Table 2. Utilization ratios of key structural components – Hierarchy of criticalities.

Member / cross section verification UP : Upright, BR : Brace, CON : Brace to upright connection, SP : Spacer, RT : Roof truss CS-1 CS-2 CS-3 CS-4 CS-5

Utilization ratio

SP

CON

> 1.50

> 1.10 to ≤ 1.50 > 1.00 to ≤ 1.10 > 0.95 to ≤ 1.00 > 0.90 to ≤ 0.95 > 0.85 to ≤ 0.90 > 0.80 to ≤ 0.85 > 0.75 to ≤ 0.80 > 0.70 to ≤ 0.75 > 0.65 to ≤ 0.70 > 0.60 to ≤ 0.65 > 0.50 to ≤ 0.60 > 0.40 to ≤ 0.50 > 0.30 to ≤ 0.40 > 0.20 to ≤ 0.30 ≤ 0.20

RT

UP,CON SP

BR UP

UP

UP

CON

BR

UP

BR

RT,BR

CON BR

CON

RT

SP,RT

SP SP For all the case studies, uprights are usually the more highly stressed parts of the structure, which is due to very large axial force resulting from the heavy unit loads plus the seismic axial force, which is caused by large seismic overturning moments. The utilization ratio of uprights lies between 0.71 (CS-3) and 1.07 (CS-4). For short free upright lengths cross-section strength is the governing design verification, while for larger free upright lengths member stability verifications are decisive.