The Reliability Research Of Beam Flexural Components Under The Serviceability Limit State

Beam in the flexural components plays an important role in the structural system,the structural performances of beam components are weakened influenced by many factors,which caused the huge casualities and economic losses.This paper does more in-depth study on the reliability and sensitivity influenced by random variables of the reinforced concrete beam bridge,steel-concrete composite beams under the serviceability limit state.Taking the maximum deflection value of structural components as the resistance,taking the actual deflection of the structural components as the load effect,consider with probability distribution types of random variables in each limit state equation.Combining FORM method to write reliability program by software MATLAB,analyzing the reliability index of reinforced concrete beam bridge under the different calculation span,concrete strength,height and height-span ratio,and further study different degrees on reliability index in the limit state function while the parameters change influenced by the concrete strength,and the sensitivities of reliability index are also discussed.Analyzing the reliability index of steel-concrete composite beam under the different concrete strength,steel grade,concrete slab thickness and calculation span,study reliability index under the boundary condition and the shear connectors,and the sensitivities of reliability index are also discussed.Results show that the reliability index and sensitivity were influenced by the calculation span,concrete strength,height and height-span ratio of the reinforced concrete beam bridge,the reliability index and sensitivity were influenced by the calculation span,concrete strength,steel grade,concrete slab thickness,boundary condition and shear connectors of the steel-concrete composite beam.Combining with the study of this paper,the results can provide effective suggestions for the applicability evaluation.