When other compression members are finished, spacing material and its riveting, backing, or welding should be arranged to hold all of the parts in line and should be proportioned for _____ compression stress.

When other compression members are finished, spacing material and its riveting, backing, or welding should be arranged to hold all of the parts in line and should be proportioned for _____ compression stress.

• A. 25%
• B. 50%
• C. 75%
• D. 100%

Answer: (B)

When built-up compression members are finished, the spacing material and its riveting, backing, or welding are there to keep all parts aligned during load and assembly. Designing them to handle about half of the compression stress gives a practical balance: they must resist enough load to maintain alignment and prevent local misfit or buckling, but they aren’t required to take the entire load path. The main members and fasteners carry the rest of the compression, so the spacer system is proportioned for 50% of the compression stress. If you tried to load the spacers more heavily (75% or 100%), you’d overbuild them and add unnecessary weight and rigidity; too little (25%) wouldn’t reliably keep everything in line under service conditions.

When built-up compression members are finished, the spacing material and its riveting, backing, or welding are there to keep all parts aligned during load and assembly. Designing them to handle about half of the compression stress gives a practical balance: they must resist enough load to maintain alignment and prevent local misfit or buckling, but they aren’t required to take the entire load path. The main members and fasteners carry the rest of the compression, so the spacer system is proportioned for 50% of the compression stress. If you tried to load the spacers more heavily (75% or 100%), you’d overbuild them and add unnecessary weight and rigidity; too little (25%) wouldn’t reliably keep everything in line under service conditions.