Nonlinear Analysis Of R/C Section With The Effect Of Crack Check

The classical MCFT(Modified Compression Field Theory) is a valid analytical method in the sectional nonlinear analysis of beams and columns, which is capable of accurately predicting the load-deformation response of the reinforced concrete beams and columns sections subjected to combined moment,shear, and axial load.In the model of MCFT, cracked concrete is treated as a new material with its own stress-strain characteristics. Equilibrium, compatibility and the stress-strain relations are formulated in terms of average strains and average stresses. Consideration is also given to local stress conditions at crack locations (crack check).On the basis of MCFT, Bentz worked out the sectional nonlinear monotonic analytical program Response2000.In Chongqing University, Huang Jianfeng and Xiong Zhiwei worked out the nonlinear sectional analysis with consideration of uniform shear stress distribution under monotonic loading and with secant stiffness method under cyclic and reversed loading respectively, but no considerations were given to the local response at the locations of cracks. In this paper, much emphasis here has been laid on the local stress-strain conditions at cracks while the MCFT is held for smeared concrete as a whole.The crack check actually represents an explicit check to ensure that the average stress can be transmitted across the cracks which make the gloable response more realistic. It is the product of MCFT based on the model of "smeared crack and average strain". However, it is a problem how to carry out crack check at cracks to ensure the stress-strain relationships of both reinforcements and concrete satisfy that described by material institutive laws. Meanwhile, significant factors relevant to the check should be confirmed when nonlinear monolithic and reversed cyclic loading conditions are considered.As the result of the above-mentioned reviews, the main work of the thesis is presented as follows:â‘  The crack check under pure shear and the combined action of shear and moment in the monolithic nonlinear sectional analysis was carried out. Then, the crack check was further introduced into that under reversed loading.â‘¡ On the basis of Xiong Zhiwei's program, the reinforced concrete nonlinear...