| Concrete bridge in bridge construction occupies a large amount in proportion, because of drawing convenience and low cost, durability and less maintenance costs, material plasticity and is designed to form a variety of structures. Concrete bridge is easy to be constructed and convenient for industrial construction, and it is renowned for its overall performance good and stiffness, therefore, it is widely used in bridge construction. But for the engineers, considering the designing requirements of the continuous improvement and bridge health, longevity, durability and other propositio ns put forward, the design process needs to be considered more fully. The analysis of concrete bridges which suffer from a variety of adverse effects when they are exposed in the external environment in bridge design is very important. This also increases the amount of calculation several times than the traditional design means nearly. The advancement of application of computer technology and the finite element method results in a functional bridge software and solution strength general-purpose finite element analysis software, which analyzes for bridge load effects to bring the convenience and accuracy. But due to the limitations of the use of general-purpose finite element software, as well as domestic bridge software software development immaturity, building a complete and mature bridge structure integration platform which combine modern computer technology and finite element method for analysis has become a requirement. In this paper, the bridge structure finite element analysis and evaluation software IPSAA will be used to carry out the processing of load analysis of three common concrete bridge structures.①Discusses the concrete bridge under the influence of ambient environmental conditions, the structure is generally subjected to three types of temperature load: Sunshine Thermal load, sudden drop in temperature loads and annual temperature load, and three loads are generally linearly or nonlinearly distributed in concrete beams. According to the distribution in the form of temperature loads, it is expected to deduct the loading column matrix of the equivalent nodes based on equivalent loading methods. Meanwhile finite element matrix affected by temperature loads is easy be obtain via principle of virtual work. Combined equivalent load method and finite element formulation ideas, a software module for bridge temperature load calculation is written with VB.NET on IPSAA platform. and it verifies the case of sudden drop in temperature loads and annual temperature load. and confirms the temperature load calculation module program correctness.②Presents two commonly used methods of prestressed load analysis: integral and separate. After comparing the advantages and disadvantages of both, this article aims to deduct the computational formula to describe the solid geo metry of prestressed steel beam from the ideas of equivalent load method; In accordance with computational theory about the loss of prestress stipulated in National Code of Bridge(JTG D62), a software module is devised with APDL based on ANSYS platform to analyze prestress effect. Through numerical example confirms the calculation of the reliability of the program.③ This article describes the contraction creep of concrete in parallel with summarizing the computational module of contraction creep for three kinds of frequently- used concrete. In the shrinkage and creep analysis methods, based on the existing theories and Contraction Creep Strain-Stress Equation, a basic equation on displacement method is deducted incorporated age-adjusted creep effect into finite element method. According to National Code of Bridge(JTG D62) provisions concerning the calculation of shrinkage and creep, a software module is written to analyze shrinkage and creep based on displacement method. Bolstered by verification of computational example, the feasibility is well justified to gauge concrete contraction creep with the method of shift creep analysis. |
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