Analysis of Plane Frames considering Material Nonlinearity

• Main Author: Biswas, Suprakash
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-1994
• Subjects: Aerospace engineering; Civil engineering; Materials science; Morphology
• ISBN: 9798357587091

The nonlinear stress-strain behaviour of material has been considered in the analysis of plane frame structures. In order to consider material nonlinearity in the analysis of plane frames, the linear members have been discretized into a suitable number of one dimensional finite elements. The first part of the work consists of the consideration of material nonlinearity in the analysis of structural steel plane frames subjected to static and dynamic loading. The second part of the work deals with the inelastic analysis of reinforced concrete plane frame structures.The analysis of reinforced concrete plane frame structures includes the consideration of bi-linear stress-strain relationship of concrete vis-a-vis the rectangular parabolic relationship adopted by 13:456-1978. Three bi-linear curves have been modeled for the compressive stress-strain distribution of concrete by replacing the parabolic part with an initial tangential line, a chord and a straight line based on equal total energy or area under the total stress-strain curve. The stress block parameters of concrete and the design parameters for R/C sections have been studied. The moment-curvature relationship for R/C sections has been established and has been used in the inelastic analysis of reinforced concrete frame structures.After the extensive numerical study, it has been concluded that the bi-linear stress-strain models provide faster result compared to the rectangular parabolic stress-strain relationship of concrete. Bi-linear model of stress-strain curve of concrete based on equal total energy gives results which are in close agreement with the results obtained by the use of rectangular parabolic stress-strain relationship in accordance with IS:456-1978. Finally, this model is recommended for simplification of theory, design, numerical work and saving in computational time.