This paper compares rigid-frame vertical bracing systems against "K" or "X" truss systems, according to height variation. The adopted models used were based on technical information from a standard project. Structural efficiency was analyzed by comparison of the ratio of the number of pavements to their horizontal dislocation, structural strain and perfiles adopted in dimension models. In the rigid-frame vertical bracing systems, structural strain and horizontal dislocation were greater than in the truss systems. The rigid-frame vertical bracing system also requires more steel, providing for a heavy, less economic structure. After 24 floors, the rigid-frame vertical bracing system becomes impractible, since at this point it no longer meets acceptable dislocation standards. For structural calculations, comparisons between the linear and non-linear analysis (P-delta effect) were used. It was concluded that non-linear analysis should be considered in the design of buildings, particularly those very tall, since it indicates true strain and major structural displacement. This paper proves that there are advantages in using the truss systems for multiple-story buildings and that it is necessary to analyse the P-delta effect for more efficient building design.
Bracing; trusses; frames; building; steel
