An Analytical Study on the Behavior of Reinforced Concrete Interior Beam-Column Joints.
Degree: PhD, Civil Engineering, 2019, Virginia Tech
Reinforced concrete (RC) moment frames are one of the most popular structure types because of their economical construction and adaptable spaces. Moment frames consist of grid-like assemblages of vertical columns and horizontal beams joined by cruciform connections commonly labelled as beam-column joints. Because of the regularity of the grid and the ability to have long column spacing, moment frames are easy to form and cast and result in wide open bays that can be adapted and readapted to many uses. In RC structures, steel bars embedded in the concrete are used to take tensile forces, as concrete is relatively weak when loaded in tension. Forces are transferred between the steel and concrete components by so-called “bond” forces at the perimeter of the bars. The proper modeling of the behavior of bond forces inside the beam-column joints of reinforced concrete moment frames is the primary objective of this dissertation. Reinforced concrete moment frames constitute a notable proportion of the existing buildings in earthquake-prone regions in the United States and throughout the world. The beam-column joints are the most crucial elements in a RC moment frame structure as any deterioration of strength and/or stiffness in these areas can lead to global collapse of the structure. Physical experimentation is the most reliable means of studying the performance of beam-column joints. However, experimental tests are expensive and time-consuming. This is why computational simulation must always be used as a supplemental tool. Accurate simulations of the behavior of beam-column joints is important for assessment of the local and global behavior of beam-column joints. However, most of the existing analytical approaches for interior beam-column joints have either failed to account for the bond-slip behavior and the triaxial compressive state of confined concrete in the joint correctly or require so many calibration parameters as to render them impractical. The present study aims to provide reliable numerical methods for evaluating the behavior of two-way beam-column-slab interior joints. Two methods are developed. The v first method is a complex finite element model in which the beam-column joint is subdivided into many small 3D parts with the geometrical and material characteristics of each part carefully defined. Since the number of parts may be in the hundreds of thousands and the geometry and material behavior highly non-linear, setting up the problem and its solution of this problem requires large effort on the part of the structural engineer and long computation times in supercomputers. Finite element models of this type are generally accurate and are used to calibrate simpler models. The second method developed herein is a nonlinear truss analogy model. In this case the structure is modelled as nonlinear truss elements, or elements carrying only axial forces. When properly calibrated, this method can produce excellent results especially in capturing large shear cracks. To evaluate the accuracy and to quantify the current…
Advisors/Committee Members: Leon, Roberto T. (committeechair), Koutromanos, Ioannis (committeechair), Roberts-Wollmann, Carin L. (committee member), Eatherton, Matthew Roy (committee member).
Subjects/Keywords: Interior Beam-Column Joint; Reinforced Concrete Structures; Nonlinear Finite Element Analysis; Bond-slip Behavior; Nonlinear Truss Model; ACI352
to Zotero / EndNote / Reference
APA (6th Edition):
Xing, C. (2019). An Analytical Study on the Behavior of Reinforced Concrete Interior Beam-Column Joints. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/92873
Chicago Manual of Style (16th Edition):
Xing, Chenxi. “An Analytical Study on the Behavior of Reinforced Concrete Interior Beam-Column Joints.” 2019. Doctoral Dissertation, Virginia Tech. Accessed December 11, 2019.
MLA Handbook (7th Edition):
Xing, Chenxi. “An Analytical Study on the Behavior of Reinforced Concrete Interior Beam-Column Joints.” 2019. Web. 11 Dec 2019.
Xing C. An Analytical Study on the Behavior of Reinforced Concrete Interior Beam-Column Joints. [Internet] [Doctoral dissertation]. Virginia Tech; 2019. [cited 2019 Dec 11].
Available from: http://hdl.handle.net/10919/92873.
Council of Science Editors:
Xing C. An Analytical Study on the Behavior of Reinforced Concrete Interior Beam-Column Joints. [Doctoral Dissertation]. Virginia Tech; 2019. Available from: http://hdl.handle.net/10919/92873