Behavior & Numerical Modelling of Reinforced Concrete Members for 7th and 9th semester 2011

Generalities

The course Behavior & Numerical Modelling of Reinforced Concrete Members is given by Professor Daniel A. Kuchma (University of Illinois) and only once. It's offered to PhD and Master students interested in the design, behaviour, and numerical modelling of the response of concrete.

Schedule

 The course takes place on Wednesdays from 0915 to 1200 , classroom CM 1 113 .

Course motivation

Traditional structural engineering design practice is focused on strength design in which the demands are determined using linear elastic analysis methods and the calculated strengths are determined using provisions in codes-of-practice. Integrated analysis and design software have been produced to support and institutionalize this approach. However, this approach has several major shortcomings, including:

  • that structural concrete is not a linear elastic material such that the true demands in indeterminate structures may be significantly different than those determined by linear elastic analysis methods
     
  • that code provisions are usually empirical and derived from the types of experiments that do not reflect the reality of what is designed with these provisions
     
  • not being effective at ensuring that the structure will have good performance under service loads or overloads
     
  • not considering the influence of non-structural elements
     
  • not enabling the use of new materials and design concepts

The digital and information technology revolution are enabling an integration of design, fabrication, and construction through the use of Building Information Modeling (BIM) approaches. As part of this process, detailed digital models of the entire structure are produced. This lays the foundation for the use of Holistic Inelastic Analysis and Design (HIAD) approaches. Automated meshing routines make it possible to create complete and accurate models of the structure under design or analysis. Many types of computational tools are available to predict the full response of these modeled structures. However, we are ill prepared to safely and effectively use these tools.

 

                                                                     Structural concrete

                                              

                              Strength refers to the ability of a structure to resist loads without failure.

 

Course program 

 

The learning objective for this course is for students to become safe and effective users of inelastic finite element tools for the design and analysis of concrete structures. It is the thesis of this course that the use of these types of tools is the next evolutionary step in design practice, and that academic institutions are best suited to train students and practicing engineers to use these tools.

In the first half of this course, students will learn about the sectional response of prismatic members and of continuums. They will implement behavioral models using Matlab to create beam and continuum elements for predicting the inelastic response of beams, frames and complex regions.

The second half of this course is concerned with model validation and the use of commercial inelastic finite element software. It includes the more advanced topics of fracture, bond, and shear in beam elements, and their implementation in commercial software. The motivation for this course is more fully described below, followed by a description of the four course assignments and culmination project options. There will be no oral or final examination in this course.

 

Course program

Course lectures

Exercices
A brief description of main assignments is given below: 

  • Assignment 1: Develop a computer program (suggested Matlab or Java) to predict the response of a linear elastic beam and a linear elastic frame to variable loadings, the aim being to  develop programming skills and to refresh the understanding of matrix analysis of frame structures. The students are required to develop an interface for this program that presents the shape of the undeformed structure with the pattern of imposed loading as well as the deformed shape. The relative linear elastic stiffness characteristics of this frame should also be displayed and fully adjustable. The completed program for this assignment will be used again in Assignment 3.

  • Assignment 2: Develop a computer program to predict the moment-curvature response of an arbitrary reinforced concrete section (rectangular, T, or I shaped). Tension stiffening need be considered such that the prediction can also be used to define the non-linear stiffness characteristics (EI)crk of a beam element. The interface for this program is required to include a display of the shape of the cross-section, strain and stress profiles, and the moment versus curvature response that allows the user to scroll back and forth over the loading history. 

  • Assignment 3: Merge Assignments 1 and 2 so to create a program for predicting the non-linear response of reinforced concrete frames to variable loadings.

  • Assignment 4: Develop a program for predicting the response of reinforced concrete membrane elements to all imposed actions using the Modified Compression Field Theory.

  • Project Options: In the latter part of the course capabilities of non-linear finite element analysis programs including VecTor2, ATENA, and DIANA are introduced. The students are given the option of completing one of two types of projects. One of these is to extend the functionality of assignments 2 to 4. For example, there could add the effect of shear to the program that they created for Assignment 3, or build a completed 2D continuum analysis program starting with what they did in Assignment 4. They could also use a 2D non-linear continuum analysis tool for predicting the response of a tested structure to imposed loadings, and then they compare the predicted and measured response to assess the capabilities of the computation tool that they used.

 

Assistant

 Brantschen Fabio

Examination

 During the semester as follows: Assignments + Project + Term test

Links

 Official page of Professor Daniel A. Kuchma

Seminar: Structural Engineering 2050: How Academia Can Shape the Future (29/09/2011, GC C 330)

 
EPFL 2010 EPFL 2004