Integrating Manufacturing Geometric Imperfections In The Inelastic Behavior Modeling Of Joints Used In Three-Dimensional Structures

Three-dimensional structures follow design practices on the common assumption that joints are either rigid, or pinned. However, the non-linear behavior of engagement of the joints is required to be incorporated into the analysis. This research is intended to incorporate manufacturing geometric imperfections into the mechanical analysis of reticulated space structures jointing systems. Imperfect jointing systems deviate from the as-designed models in such a way that the location of the connecting surfaces does not follow the designed interaction path between the component elements. However, current structural analysis methodologies do not consider manufacturing geometric imperfections and often fail to consider the stresses caused as a result of these imperfections. The objective of this Dissertation is to develop a procedure to better understand how surface imperfections affect the inelastic behavior jointing systems used in the construction of reticulated structures. Finite element analyses, using the MSC Patran/Nastran software, of a reticulated structure jointing system were conducted to characterize its mechanical behavior. Numerical simulations were conducted to characterize the mechanical behavior of the as-designed jointing system, and the as-built jointing system engagement. An experimental investigation of the jointing system under tensile loading conditions was performed to obtain the real behavior of the jointing system for comparison to the numerical simulation results. Results of the numerical simulations and the experimental investigation provided the basis to assess how the manufacturing geometric imperfections impact the mechanical behavior/capacity of jointing systems. The results of these studies lead to a more realistic modeling of the joints used in reticulated three-dimensional structures. This research is important as it can be used as a base model to develop new approaches considering imperfections of the component elements in the inelastic analysis of the jointing systems used in three-dimensional structures