The Calculation Of Concrete Creep And The Simulation Analysis Of Bridge Construction

Creep is one of the material properties of concrete by which it continues deforming over considerable lengths of time at constant stress or load. A concrete structure under short-time loading results in elastic deformation. If the load were maintained, the deformation would increase to several times its elastic value. Creep not only brings on deformation, but also redistribution of stress and loss of prestress. The influence of creep on bridge structures is especially severe. The calculation of creep has become necessary in bridge designing and construction.However, creep of concrete and its influence on bridge structures are hard to predict and control. The calculation is very complicated and the results are not accurate. There are lots of factors that affect the nature of creep, including internal factors and external factors. These factors must be considered comprehensively in designing and construction. Taking into account the material properties of concrete, the process and the method of construction, this paper introduces using finite element method (FEM) to solve this problem. Based on the second-development of the FEM software——ANSYS, this paper focuses on the calculation of concrete creep and the simulation of bridge construction in ANSYS. By its original functions, creep of concrete could not be solved. According to the different definitions of creep coefficient in different construction codes, a program to solve creep of concrete is written by FORTRAN language. By means of UPFs,ANSYS can use this program to solve creep problems. Composite cross section with multiple materials can be analyzed in ANSYS, so it's convenient to take this advantage to calculate the redistribution of stress in reinforced concrete structures or steel-concrete composite structures under the condition of compatible deformation. Construction information can be read and saved in ANSYS by UPFs, and macro commands written by APDL can control the calculation flow, the element birth and death, thereby simulating the bridge construction. The calculation results agree with the practical results. Simulation analysis provides accurate and visible results that can be referred to in practical designing and construction, so it's valuable in bridge structure engineering.