The dynamic analysis of structures differs from static analysis mainly due to the consideration of load variations over time. Harmonic loads, also known as cyclic loads, are among the most critical factors requiring precise evaluation to predict structural behavior accurately. These loads involve periodic variations over time, such as those induced by earthquakes, wind, or traffic, and can lead to complex responses in structures, including significant nonlinear effects. Thus, it is essential to design buildings to ensure safety and comfort, avoiding unexpected performances. In dynamic analysis, the use of computational simulations is crucial, as it provides more precise results and enables complex analyses to which a building may be subjected. This approach allows for the anticipation of potential problems and ensures that both static actions (self-weight, permanent loads) and dynamic actions (winds, vibrations, impacts) are properly considered and verified. Then, the main objective of this work was to develop a methodology for the dynamic analysis of 2D reinforced concrete truss structures, considering the physical nonlinearity of the material (cracking). To achieve this objective, Finite Element Method (FEM) was employed for the spatial discretization of the structure domain, and Newmark method was used for the temporal discretization. Physical nonlinearity was considered through the material's constitutive equation, according to ABNT NBR 6118:2023, with the update of the stiffness matrix over time. Newton-Raphson method was used to obtain the solution of the nonlinear problem in the process of verifying the reinforced concrete section. The results obtained were compared with those of well-established market software in their student, free, or temporary versions to validate the robustness and efficiency of the proposed algorithm.
