Structural engineering demands increasingly lighter systems, which can cause instability problems and compromise performance. A high slenderness index of a structural element makes it susceptible to instability. It is important to understand the problem, the limits of stability, and its postcritical behavior. An example that can occur in collapsed arches under a cross load is the dynamic snap-through behavior, where the structure in a given equilibrium condition jumps to a new remote equilibrium setting, causing usually sudden curvature. The semirigid connections are a source of physical nonlinearity and can influence the overall stability of the structural system, in addition to the distribution of stresses in the same system. Conventional approaches make use of static considerations. However, instability problems are inherently evolutionary processes, so a transient analysis is necessary for a complete description of structural behavior. The present work evaluates the geometrically nonlinear dynamic behavior of collapsed arches subjected to transverse force and plane frames with semirigid connections. The time domain responses, via Newmark's Method and positional formulation of the Finite Element Method, were obtained in terms of displacements, velocities, acceleration, and phase diagrams.

Atualmente o sistema como o Steel Frame vem conquistando espaço na construção civil brasileira. Por ser um sistema relativamente novo no Brasil comparado a sistemas construtivos tradicionais, estudos e técnicas que simplifiquem o processo de cálculo e execução são de grande relevância. O presente trabalho apresenta curvas de resistência versus comprimento para alguns perfis U e U enrijecido utilizados como montantes de paredes internas em sistemas Light Steel Frame. estas curvas podem ser utilizadas como ábacos para pré-dimensionamento destes elementos estruturais. Os resultados foram comparados aos fornecidos pelo programa DimPerfil, e apresentaram boa concordância entre si.

Comparativo entre ligações rígidas simétricas com perfis T laminados (LT/LMTS) e ligações rígidas com chapas de cabeça parafusadas assimétricas (LMPA): análise de resistência versus peso de seus elementos constituintes Comparison between symmetric rigid steel connections with hot-rolling wideflange T profiles (LT / LMTS) and rigid steel connections with asymmetric bolted extended end plates (LMPA): strength versus weight analysis of its elements

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Estimativa da frequência fundamental de vibração em vigas a partir da teoria da linha elástica associada ao quociente de rayleigh Estimation of the fundamental frequency of vibration in Beams from the elastic curve theory associated with the rayleigh quotient