| The main purpose of this dissertation project was to study the shear behavior or shear bearing capacity of through diaphragm connectors connecting or integrating H shaped steel beams and hollow square steel columns reacting under seismic influences.Numerical and theoretical analyses were performed in this thesis.Firstly,three through-diaphragm connections between steel square tubular column and Hshaped steel beam were analyzed under cyclic loading using finite element analyses software called ABAQUS standard 2020 to investigate the seismic shear behaviors of the panel zones.The results obtained after analyses were simulated with an already validated and approved experimental test having the same geometric and material properties.The studied parameters included different configurations of the connections(two interior and exterior connections).The effectuated FE specimens offered similar hysteresis loops behavior,accurate simulations concerning shear forces with the already approved experimental test reference.The failure mode and load displacement reactions of the finite element developed specimens were analyzed and discussed.The main failure mode recorded after FE analyses was shear failure.Maximum yield and ultimate load responsible for shear failure at the diaphragm joints including the maximum strains were also analyzed.From the analyses,it was observed that a practical proportional similarity exist between ultimate load and shear strength as an increase in ultimate load triggers proportionately an increase in shear resistance of the diaphragm.Secondly,based on the results and proper/accurate simulations of the FEA with the approved test reference,21 specimens were analyzed parametrically using the software abaqus to evaluate the key factors affecting yield/ultimate load and ultimate shear capacity of the diaphragm connector.Based on the FE parametric operations,the thickness of the tube web,diameter of opening in the through diaphragm connector and cantilever length of the joint were confirmed to be the 3 main factors influencing the shear strength.The thickness of the tube web or panel zone tube was considered to be the most influential as its variation massively affected the shear resistance compared the influence of the diaphragm opening and cantilever length.Thirdly,a formula required to calculate the ultimate shear force was generated theoretically using the regression method.A total of 102 specimens were analyzed numerically.3graphs were generated consisting of 5 curves each.The trend or slope of the curves representing the influence of each factor on the shear force was evaluated and the formula used to evaluate the shear force of the through diaphragm connection in the panel zone was developed.The theoretically generated formula or newly designed equation was used to calculate the ultimate shear capacity of the joint and the results were compared with validated results obtained from the parametric analyses.It was confirmed that the newly designed equation or the thesis generated formula produced similar results to the FE parametric analyses.Therefore,the proposed formula was considered accurate and trustworthy. |
