Load analysis was conducted on bolted-flange connecting system, and the deformation-compatibility equation of the system was derived.

Fault tree analysis of flanged joint system at high temperature;

Cyclical stress calculation of bolts for flanged connections at elevated temperature;

Life expectation method of flanged connections based on creep analysis at elevated temperature;

The domestic research on rectangular-tube flange connection is completely blank,and no design method is given in foreign references.

In most of the buildings,the H-section columns are spliced with high-strength bolts or full penetration groove welding,box and pipe section columns are spliced with full penetration groove welding,but in the design,flange connection is demanded on partial rigid joints,which is required to meet the bearing capacity only.

On the basis of theoretical formula deduced by yield line theory,the FEManalysis on loading capacity of flange connection is carried out.

By comparing the simulation results under different main bearing load,the effect of the coupling flange,the mounting stiffness and the elasticity of shaft coupling on main bearing load were discussed.

After Comparison with flange conjunction between duct in technical performance, flangeless conjunction isbetter in construction process, with high strength, nice appearance.