The Research On Method Of Principle Stress Trajectory For Typical Disturbed Region Of Reinforced Concrete Structure

Method of the principle stress trajectory is an important means of configuring strut-and-tie model,and strut-and-tie model(STM)is the mechanism of disturbed region(D-region)of reinforced concrete structure.This paper has conducted a series of researches for method of principle stress trajectory based on the configuration of typical D-region.The researches can be listed as follows:(1)The research of general programming.Using the Python script language of the finite element software Abaqus,this paper makes a secondary development for the software,and the automatic drawing of the principle stress trajectory for typical disturbed region of reinforced concrete structure is provided.(2)The research on method of the principle stress trajectory in the linear elastic stage.The developed program is used to draw the principle stress trajectory and configure STM for seven typical D-regions,including deep beam,local compression structure,corbel,diaphragm,bracket,pier cap and pile cap.On basis of these,the current research results are checked as a whole,and the supplements and corrections are presented to the three components of automatic drawing program of the principle stress trajectory,including(1)for the first point;(2)standard for algorithm of the next point choice;(3)selection and termination criteria;and(4)smoothness for the principle stress trajectory,menwhile a deepening study of the three-dimensional principle stress trajectory is carried out.Comparative analysis shows that: the results obtained from this paper are better than the current ones.(3)The research on method of principle stress trajectory in the nonlinear stage.The line point termination criterion for method of the principle stress trajectory in the nonlinear stage is proposed.The automatic drawing of nonlinear principle stress trajectory for typical Disturbed region of reinforced concrete structure is presented.The rationality of the proposed method is validated by taking the reinforced concrete deep beam as an example.