Object-oriented Reinforced Concrete Structure Nonlinear Finite Element Analysis

A reinforced concrete structure is a type of important structure in engineering. During studying mechanics character of reinforced concrete, reinforced concrete finite element method attracts scholars' more and more attention thanks for the improvement of finite element method and the rapid development of computer technology. But, traditional reinforced concrete finite element programs were developed according to the process-oriented method, which results in the limited expandability and the difficulty of maintenance. This paper manages to create object-oriented reinforced concrete finite element program and improve concrete cracking model.In programming, employing object-oriented method and using Visual C++ 6.0 programming tools, the core concepts of reinforced concrete finite element are abstracted into node class, element class, load class, matrix class, vector class, equation class and like these fundamental classes. Besides, applying classes like concrete class and steel bar class are also constructed. With realizing these classes, reinforced concrete finite element nonlinear computing program is developed.As far as dealing with the problem of concrete cracking is concerned, traditional programs usually employed smeared cracking model and discrete cracking model. This paper, considering the character of stress redistribution after cracking, divides concrete elements into crackable elements and uncrackable elements. On one hand, this cracking model does not need to generate new elements and save computing time, which is similar to the benefits of smeared cracking model. On the other hand, in terms of drawing crack, it is also the same vivid as discrete cracking model.The developed program also has some post-processing functions including structure shape map, discrete structure mesh map, structure displacement map, cracking map, stress map of steel bar, principal stress map of any section, searching displacement of any load step, load-deflection curve map of any node and so on.According to the result of computing examples, object-oriented reinforced concrete finite element program can be created in shorter period, having higher reuse rate of code, stronger expandability and more convenient maintenance. Moreover, better pre- and post-processing functions can be added easily. Cracking model proposed in this paper combines the benefits of smeared cracking model and the advantages of discrete cracking model, which is good to reinforced concrete nonlinear finite element analysis.