Comparisons Of Calculation Methods Of Bearing Capacity For Two-hinged Parabolic Steel Arch Under Full-span And Half-span Loads

Steel arch structure is a common form of building structure, which is used in large-span steel structure widely. The destruction of the steel arch structure will lead to serious losses of people’s lives and properties. Therefore, the design and research for steel arch structure are necessary. In this paper, through the establishment of two hinged parabolic steel arch structure model, firstly using ANSYS finite element method for steel arch structure is consistent with the defect first order buckling modal analysis, while the two hinged parabolic steel arch structure established by comparing the calculation results be linear elastic analysis, including comparison and contrast just load effect coefficient be consistent with the subsequent improvement defective steel arch structure of second-order analysis and comparison of the two changes in the stress analysis of steel arch structure of the second order, the last of the two steel arch structure stress analysis of the whole process.Meanwhile, the two hinged parabolic steel arch structure is established and linear elastic analysis and the second-order analysis of the improved consistent defects steel arch structure are performed. The comparison of load effect coefficient of the two methods under linear elastic analysis and the stress vary condition under the second-order analysis of the improved consistent defects steel arch structure is performed. The internal force arranging condition of steel arches under combined full-span and half-span loads would vary largely with the varying of load ratio. However, most relative formulas of in-plane ultimate strength of steel arches are obtained by studying the strength under a single load. Thus, it lacks full considerations of the applicability of bearing capacity formulas with a combined full-span and half-span load. To overcome this shortcoming, taking the two-hinged parabolic steel arch as the studying object, several methods for bearing capacity calculation, such as the method proposed in the current Chinese design specification of steel arch structure, the method proposed by the Japanese scholars Kuranishi and Yabuki proposed, and the finite element simulating method based on both the perfect arch and imperfect arch, and the strength design method of consider the second-order effects. The analysis of the results showed that the ultimate bearing capacity of the results of different methods vary widely; Within the range of parameter, because the Chinese design specification of steel arch structure considered initial imperfections, residual stress and plastic development and other factors at the same time, when half-span load accounts for a large proportion, ultimate bearing capacity calculation of the Chinese design specification of steel arch structure method is bigger than other four methods, which makes steel arch structure designed unsafe; And when full-span load accounts for a large proportion, ultimate bearing capacity calculation of the Chinese design specification of steel arch structure method is smaller than other four methods, so that the Chinese design specification of steel arch structure method designed steel arch structure is conservative.By China’s 《Technical Specification for steel arch structure》 (JGJ/T 249-2011) and the method proposed by Japanese scholars Kuranishi and Yabuki, the analysis and comparison of internal force of two hinged parabolic steel arch structure established are performed and its design axial force and bending moment curve are determined.