Research On Design Method Of Concrete Component Based On Strut-and-Tie Model

Strut-and-tie model as a design method of concrete structure, reflect distinct advantage compared to traditional design method when we make stress analysis and reinforcement design for interference zone, foreign countries have the mature theoretical system,and have been applied on concrete structure design code.the study on strut-and-tie model started later in China, Some scholars made investigate on design concrete structure by this way, but achievement focus on deep beam,corbel, openings beam, this paper use strut-and-tie model on design normal section strength design of bending members, oblique section strength design of bending members, normal section strength design of compression members.Through making elastic stress analysis for bending members with different span depth ratio, the difference between stress characteristics of deep bending members and normal bending members were acquired, based on stress distribution of compression, strut-and-tie model of deep bending members were builded. Making finite element analysis for normal bending members with different reinforcement ratio, and building strut-and-tie model based on stress distribution of compression in ultimate state, and the relationship between the width of concrete strut and reinforcement ratio was acquired.Through making elastic element analysis for beams without stirrups with different shear span ratio, the difference of shear behavior of beams with different shear span ratio were acquired,and strut-and-tie model were builded by topology optimization method, making comparation between the results of strut-and-tie model method and Chinese code method, the result of bearing capacity used strut-and-tie model method were close to Chinese code method. Making finite element analysis for concrete beams with different stirrup ratio, strut-and-tie model method and relationship between the angle of concrete strut were proposed based on stress distribution when stirrup yielded.Through making finite element analysis for eccentric compression members with different reinforcement ratio, the effects of reinforcement ratio on the height of concrete compression, and the calculation method of strut-and-tie model on normal normal section strength of compression members was proposed.Finally, making comparision of strut-and-tie model method result、FEM result and Chinese code result,these results were highly similar. So use strut-and-tie model method on design normal section strength design of bending members, oblique section strength design of bending members, normal section strength design of compression members are reasonabal.