Papers by Keyword: Moment-Curvature Relation

Abstract: A pseudolinear equivalent method is proposed to analyze the nonlinear deformation of reinforced concrete structure member. In this method, the real moment of a bending member is transformed into equivalent moment by means of acquiring the bending moment-curvature relation of the section, and then the equivalent concentrated forces along the member are gained through the differential relationship between bending moment, shear force and distributed force. By this method, the problem of nonlinear system can be transformed into the problem of linear system. This method can analyze the deformation of RC structure members with constant or variant sections, which can be extended to analyze the nonlinear deformation of the structure members made of other kinds of engineering materials. The analyzed result given by this method fits the result attained from finite element method very well, which proves the feasibility of the model.

Abstract: A lot of bridge reinforcement and rehabilitation projects are been implementing throughout China and many countries in the world. However, some fundamental questions still remain unsettled, and this paper addressed one of them, which is the bearing capacity of strengthened beams. We analyzed the loading process of beams after strengthening with strain lag effect, and focused on several critical states. To validate our conclusions, we developed a non-linear FEM program, and compared the data yielded by program with those from reference. We found that for adequate reinforcement RC beams the influence of strain lag effect on the bearing capacity depends on the property of reinforcing material. The conclusion matched with experiment very well.

Abstract: Because the SRC (steel reinforced concrete) structures fully combine the advantages of two materials i.e. steel and concrete they had been widely used in high-rise buildings. Completely study the moment-curvature relation of this kind of member is essential to a nonlinear analysis of this type of structures. The fiber model method based on the section discretion directly reflect the restoring characteristics of the member though the stress-strain relationship of steel and concrete. It can be applied to analyze section with any configuration. In this paper, the hysteretic moment-curvature relation of SRC column is analyzed by coding and verified by available test result. And finally several factors influenced on the M-Фrelation is discussed.

Abstract: Ultra high toughness cementitious composite (abbreviated as UHTCC) shows significant pseudo strain hardening behavior and offers prominent tension strain ability of more than 3% when subjected to uniaxial tension load. The failure pattern of the UHTCC components exhibits multiple fine cracks with crack width lower than 100μm even corresponding to the ultimate tensile strain state. Four-point bending investigations of reinforced ultra high toughness cementitious composite (RUHTCC) members without web reinforcement have been carried out due to the excellent crack dispersion and strain energy absorption abilities of UHTCC material, aiming at design issues of strictly anti-cracking structures or aseismic design in key parts of structures such as beam column joint when using UHTCC. The moment-curvature curves have been measured and compared with the theoretical analysis proposed before. There is a reasonable agreement between them, especially that both moment and curvature present little difference before yielding. According to experimental results of RUHTCC beams with three different reinforcement ratios, UHTCC can delay yielding of reinforcements and improve load bearing capacity and ductility of structures or components compared with ordinary reinforced concrete beams, then steel products can be saved. The possibility of corrosion should be evidently reduced in respect that RUHTCC can effectively control crack. Accordingly, durability of structures improves by using UHTCC members.