Analysis And Application Of Time-varying Reliability For Reinforced Concrete Simply Supported Beam Based On Numerical Simulation

With the rapid development of Chinese highway construction, as a road transporthub, bridges play a more and more important role nowadays. Studies have shown that,shortage of carrying capacity of the existing reinforced concrete bridges has becomeincreasingly evident, due to bridge structural damage and material degradation. Howto exactly calculate the reliability of existing bridges, and according to time-varyingreliability of the existing bridge, how to predict the bridge life, have become agrowing concerning topic for many scholars.Most of the structure reliability calculation methods are obtained by calculatingstructural performance function. However, it is difficult to get access to the specificperformance function for most of the engineering structures. ANSYS finite elementprobability analysis can solve the complex structural reliability analysis problems, ofwhich Monte Carlo method is applied to reliability calculation and verification forsimple structure, while response surface method is suitable for complex structuralreliability calculations. But for the reliability calculation of the simple structure, theresponse surface method has no advantage. For reinforced concrete simply supportedbeam, by integrating finite element analysis and reliability calculation of reinforcedconcrete simply supported beam together, and using ANSYS response surface methodto make numerical simulation to analyze its reliability problems, the results have highaccuracy and effectiveness.In this paper, finite element models of simply-supported reinforced concreteT-beam structure are established at first, and then stochastic finite element responsesurface method is used for reliability analysis and calculation of the simple T-beam.Regardless of load changes, with tensile reinforcement’ yield as the failure criteria forsimply supported beam in ultimate limit state, it can be concluded that cross-sectionarea of steel has the maximum impact on the reliability of the simply supported beam, and elastic modulus of steel as well as concrete have bigger impact on steel stress,while beam height and beam width have a relatively small impact on the reliability.Considering the changing of concrete strength, steel strength, and cross-section areaof steel over time, and combined with the engineering example of reinforced concretesimply supported beam, real time-dependent reliability analysis of simply supportedbeam is adopted to obtain the changing curve of reliable indicators over time. Andbased on the corresponding life prediction standard, the residual service life of thesimply supported beam is estimated.