m15l38 - Module 15 Redistribution of Moments Version 2 CE...

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Module 15 Redistribution of Moments Version 2 CE IIT, Kharagpur
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Lesson 38 Redistribution of Moments – Theory and Numerical Problems Version 2 CE IIT, Kharagpur
Image of page 2
Instructional Objectives: At the end of this lesson, the student should be able to: explain the concept of redistribution of moments in the design of statically indeterminate reinforced concrete structures, explain the behaviour of statically indeterminate reinforced concrete structures with increasing loads till the collapse of the structures, state the advantages of redistributing the moments in statically indeterminate reinforced concrete structures, identify structures when such redistributions are to be made based on the analysis of structures, mention the reasons why full redistribution is not allowed in reinforced concrete structures, specify the stipulations of IS Codes about the redistribution separately when the structure is designed by working stress method and by limit state method, apply the theories in solving numerical problems of statically indeterminate beams of one or more spans as per the stipulations of IS Code. 15.38.1 Introduction Statically indeterminate structures made of reinforced concrete like fixed ended one span beams, continuous beams and frames are designed considering internal forces like bending moment, shear force and axial thrust obtained from structural analysis. Either one or several sections of these structures may have peak values of the internal forces, which are designated as critical sections. These sections are dimensioned and reinforced accordingly. Flexural members, however, do not collapse immediately as soon as the loads at a particular section cause bending moment exceeding the maximum resisting moment capacity of that section. Instead, that section starts rotating at almost constant moment. This is known as formation of plastic hinge at that section reaching its maximum resisting moment capacity. The section then transfers loads to other sections if the applied loads are further increased. This process continues till the structures Version 2 CE IIT, Kharagpur
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
have plastic binges at sufficient sections to form a failure mechanism when it actually collapses. However, significant transfer of loads has occurred before the collapse of the structure. This transfer of loads after the formation of first plastic hinge at section having the highest bending moment till the collapse of the structure is known as redistribution of moments. By this process, therefore, the structure continues to accommodate higher loads before it collapses. The elastic bending moment diagram prior to the formation of first plastic hinge and the final bending moment diagram just before the collapse are far different. The ratio of the negative to positive elastic bending moments is no more valid. The development of plastic hinges depends on the available plastic moment capacity at critical sections. It is worth mentioning that the redistribution
Image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern