Comparisons Of Calculation Methods And The Research Of Reliability Analysis Of Bearing Capacity For Two-hinged Arc Steel Arch Under Full-span And Half-span Loads

The steel arch structure is a common structure form in the structure of the building because of the large span steel structure of light weight, large span, high space utilization rate,in recent years, all the projects under construction in the increasingly high proportion. Once the improper design of structural damage, it will bring great losses to the national economy, so the real significance of the steel arch structure has very important.In this paper, two hinged circular steel arch structure under full span and half span load limit under the combination of bearing capacity. In order to study the effects of factors influence on the bearing capacity of the arch structure of circular steel, the use of Japanese scholars Kuranishi and Yabuki proposed method, finite element method, based on uniform defect and improve the structure of the finite element method, considering the two order effect of strength design method and our country "arch" technical specification for steel structure of the proposed method are compared. Results of the analysis show that, there is a big difference between the ultimate bearing capacity of structure by different methods of calculation, and when the half span load accounts for a high proportion, "rules" steel structure technology.Compared with other methods, the results tend to be unsafe.Reliability is an important index to evaluate whether the structure safety. Integral method for structural reliability is one of the commonly used method, investigate method for failure modes in series mode and parallel mode by the mixture of hybrid structural system reliability is solved, relevant research is not sufficient. This paper presents a practical method to quickly determine the mixed failure region system. The application of this method, comparative analysis of the different integration methods for solving complex hybrid system efficiency and accuracy of structural reliability. The example analysis shows that the Gauss type quadrature formulas(Gauss-Legendre integral, Gauss- Hermite integral) computational efficiency is better than that of Newton-Cotes type quadrature formulas(trapezoid formula, Simpson formula) and Monte Carlo integration method; influence the accuracy checking point position and the coordinate system for selection of Gauss-Hermite integral; there was a high correlation between the calculation accuracy and the integral interval Gauss-Legendre integral integral interval, if the selection is not reasonable, the calculation error is large. Trapezoidformula for calculation is relatively simple, the results are stable, and in solving the complex structure reliability is advantageous in allowing a large amount of calculation, the article suggests using trapezoidal integration to solve complex structure reliability.At present, the steel arch structure load effect coefficient is relatively single,under half spanload accounted for a higher proportion of structural reliability will be low, and the steel arch structure failure equation uncertainty characteristics also influence to the structure reliability level. This paper calculated the reliability index of the steel arch structure by using thetrapezoidal integral formula, to further determine the safety coefficient of the structure can provide a reference for the design of.