Non-uniform cooling of steel cross-sections during the manufacturing process generates a state of residual stresses in the cross-section. Design codes describe the distribution of these stresses in different ways. This work aims to numerically investigate the influence of these models on the behavior of bare steel and steel-concrete composite sections by the curves: flexural stiffness-bending moment, moment-curvature and yield curves (initial and full yield). These procedures are important for the study of the simplified curves used in some methodologies of the refined plastic hinge method (RPHM) analysis. The study will use the strain compatibility method (SCM), where, if the axial strain of the cross-section point is known, the section stiffness is obtained using the tangential Young's modulus derived from the materials constitutive relationship. A fiber discretization algorithm is applied and the residual stresses are explicitly inserted into the fibers automatically. The methodology was calibrated using the moment-curvature relationship and the flexural stiffness-bending moment curve. These results were numerically stable and good convergence with literature data was obtained. In general, the residual stress model of the American standard (AISC, 2016) defines a larger elastic region within the interaction diagrams then European model (CEN, 2005). The results obtained showed that the initial yield curves for steel I-sections under minor axis bending require revision for application to RPHM, mainly due to the loss of symmetry in relation to the ''M'' axis in the normal force-bending moment (''NM'') interaction diagram.
Abstract Non-uniform cooling of steel cross-sections during the manufacturing process generates a state of residual stresses in the cross-section. Design codes describe the distribution [...]
Structural elements, in many situations, are supported by other surfaces, such as soil, which may offer movement constraints in some directions. Therefore, the static and dynamic analysis of these elements considering their interaction with the soil becomes important in the design of a structural design. This paper presents the nonlinear dynamic analysis of structural systems considering such interaction through the Finite Element Method. A geometrically nonlinear beam-column element is used to model the structure, while the soil can be idealized as a continuum foundation, through the Winkler and Pasternak models. It is assumed that the foundation reacts to tension and compression stresses, so during the deformation process the structural elements are subjected to bilateral contact constraints. The analysis is based on the modeling of the structural system using the finite element method, where the Newmark integration method and Newton-Raphson iterative strategy are used in the process of solving the nonlinear dynamic equations in the time domain. Practical situations involving the interaction between soil and structure were evaluated during the study, showing the influence of contact in the natural vibration frequency and transient response of these structures.
Abstract Structural elements, in many situations, are supported by other surfaces, such as soil, which may offer movement constraints in some directions. Therefore, the static and [...]
Influence of residual stress models prescribed in design codes for steel I-section behavior 
