Un estudio del comportamiento de pilares incluyendo el régimen no lineal de los materiales

A study of column behaviour including the material

This paper reviews the structural behaviour of columns considered as straight prismatic pieces with compression loads. First, a number of different hypotheses are given in connection with the kinematic equations, constitutive relations and mechanical equilibrium conditions that can be used to formalize the different model types. Particularly, Euler?s and Kirchhoff?s classic models are mentioned, stating their most outstanding results which include the basic ideas about columns analysis. Concepts that provide the foundation for studying more general columns models are also discussed, including: load-displacement trajectories, stability, singular points (bifurcation, limit) and sensibility. After mentioning the key works in the field of plastic column behaviour (Engesser, Consider and Shanley), the above ideas are applied to the study of columns in a non-linear elastic constitutive relationship. The case of a discrete model determining the trajectory, the regions of stability as well as the bifurcation and limit points for a homogeneous and non-homogeneous load is described. Second, the continuous behaviour of the column is analysed by obtaining the equations from the model and solving two examples using generalized splines theory and the concept of equivalent linear column. Finally, an L-frame composed of a column and a beam is examined. In this case, an asymmetric trajectory is obtained, and the results of the linear and non-linear elastic solutions are compared for homogeneous and non-homogeneous load states along the section of the branch with the minimum limit load. The purpose of the above is to illustrate the elements, concepts and basic aspects that column analysis theory should cover.