A tool for analyzing and understanding the behavior of structural systems based on the principle of virtual work was developed by Dr. Finley Charney in the early 1990s. The program was called DISPAR, which stands for DISplacement PARticipation factors, and was written to work in accordance with SAP90 and ETABS. This program became outdated once newer versions of SAP90 and ETABS were released. Starting with version 11 of SAP2000, Computers and Structures released an Open Application Programming Interface (OAPI) which allowed programmers efficient access to the information in SAP2000. With this release came the motivation to update the program DISPAR to work with SAP2000 version 11 and other versions to follow. This thesis provides an overview of how the new version of DISPAR was programmed using VB.Net and OpenGL. This thesis starts off with an in depth discussion and literature review on the development of the principle of virtual work. The literature review covers how virtual work can be used as a tool to understand structural behavior as well as optimize structural performance. The updated version of DISPAR (DISPAR for SAP2000) was then used to analyze the behavior of metal building frames under various loadings. The focus of this study was to determine the effect modeling the column base connection as partially rigid has on wind drift in metal building frames. Before beginning the study, a literature review was conducted on the rotation stiffness provided by typical column base connections. The information obtain in the literature review was then used to create a finite element model of a typical column base connection in a metal building. Once the finite element model was completed, DISPAR for SAP2000 was used to conduct a study on the sensitivity of the rotational stiffness of the column base connection. / Master of Science

In a typical light metal building, the structural members are designed for the forces and moments obtained from the wind drift analysis, which assumes pinned connections at the base. The pinned connections provide no moment at the base and have zero rotational stiffness. However, in reality every connection provides some restraint and has some rotational stiffness. Hence, by considering a modeling assumption of pinned condition, the actual behavior of the connection is not captured and this results in overestimation of lateral drifts and appearance of larger moments at the knee of the gable frames. Since the structural components are designed on the basis of these highly conservative results, the cost of the project increases. This thesis investigates the real behavior of the column base connection and tries to reduce the above stated conservatism by developing a computer program or "wizard" to calculate the initial rotational stiffness of any column base connection. To observe the actual behavior of a column base connection under different load cases, a number of finite element models were created in SAP2000. Each finite element model of the column base connection contained base plate, column stub, anchor bolts and in some cases grout as its components. The model was mainly subjected to three load cases, namely gravity, wind and gravity plus wind. After performing many analyses, the influence of flexibility of each component on the flexibility of the connection was observed and a list of parameters was created. These parameters are the properties of above mentioned components which characterizes any column base connection. These parameters were then used as inputs to model any configuration of the column base connection in the developed wizard. The wizard uses OpenSees and SAP2000 to analyze the modeled configuration of the connection and provides values of the initial rotational stiffness and maximum bearing pressure for the provided loads. These values can be further used in any structural analysis which is done to calculate the lateral drift of a frame under lateral loads. This will also help in getting results which are less conservative than the results which one gets on assuming pinned condition at the base. / Master of Science

Yes / CDW-based concrete requires alkali-activators to generate geopolymerization process. These alkali-activators are difficult to be handled at the construction site and one of the rational ways to built reinforced geopolymer structures is the prefabricated construction. The connection of the precast structures is the most vulnerable component under the effect of seismic actions. Proper detailing and design of connections are crucial for sufficiently-ductile performance under seismic loading. Additionally, to achieve the disassembling and reusing of structural members, a demountable connection, i.e., dry connection, should be used instead of a wet connection. In this study, four novel fully-demountable connections for reinforced construction and demolition waste-based (CDW) geopolymer concrete members are developed. Seismic performances of these different demountable connections and one reference monolithic connections are experimentally investigated. The connections are subjected to reversed cyclic lateral displacements under constant axial loading. Comparisons are made referring to observed damage patterns, connection strengths, moment–curvature relations, initial stiffnesses, plastic hinge lengths, and energy dissipation characteristics of the proposed demountable connections and the monolithic connection. The results of the experimental study indicate that one proposed demountable connection exhibited larger lateral capacity and better seismic performance than its monolithic counterpart, whereas the other three proposals showed less performance than the monolithic counterpart. / The authors gratefully acknowledge the financial assistance of the European Union’s Horizon 2020 research and innovation programme under grant agreement No: 869336, ICEBERG / The full-text of this article will be released for public view at the end of the publisher embargo on 31 May 2024.