Simplification Of Beams And Slab Stiffness For Reinforced Concrete Structure Analysis

At present, the structure analysis becomes more complex. The calculation accuracy of structure software and the rational simplification of the structure models are more important than ever because of the huge calculation. Several key issues on the simplification of structural computation model are discussed in this paper. Some reasonable and practical improvements are given. The major researches are as follows:1) Research on the development and history of the structure analysis model. After reading the literature, the problems of structure analysis model are summarized.2) To study the simplification of floor stiffness. By establishing a series of bay with different span and thickness, beam cross-section of frame model, according to the principle of equal displacement value, with the software SATWE and SAP2000, the comparative analysis was completed. The affection regulation between the floor thickness beam cross-section, column cross-section and the amplificatory of beam stiffness are summarized. Then the beam stiffness amplification fitting formula was proposed. The results shows that the conclusion is practical and reliable.3) Research on the reasonable reduction coefficient of beam torque. With the structure software SAP2000, the floor, beam and column are simulated by shell element and beam element individually. By establishing different thickness of floor and different cross-section of beam and column, considering the eccentric of floor and beam, the beam torque reduction coefficient was suggested. Meanwhile, the main influential factors of the beam torque reduction coefficient are given as the floor thickness and secondary beam cross-section.4) The paper explores a moment redistribution method of the whole structure calculation. Considering the stiffness change of different beam section, a redistribution method to achieve the balance between beam, column and joint internal force was developed. The research result shows that when the stiffness reduction coefficient of beam end adopts0.4, the analysis result will be fit with the traditional0.85amplify method. This method is much more practical.In summary, the paper focuses on the simplification of structure analysis model. Some practical improvements were given, which may promote the development of structure model simplification.