With sufficient precision, the approximate syminetrical destabilizing critical load for the circular arch with fixed supports are calculated by Ritz method.

Based on the total potential energy of elastic curved beams by considering the geometrical nonlinearity, the theoretic solution for the flexural-torsional buckling load of fixed-end circular arches subjected to uniform compression and bending is deduced with the Retz method, taking the effects of warping rigidity into account.

This paper is based on the basic equation of polar coordinate solution in elastic planar problem,derived the state equation of planar problem of fixed arch,defined the displacement and stress triangular potential function, then obtained the accurate solution.

Plastic limit analysis of clamped circular plate under linear distributed load;

The superiority of using the generalized functions to solve mechanic problems is illustrated by an example of the bending deflection of clamped circular plate under the concentrated force,using the generalized function.

The unified solutions of load-carrying capacities, moment fields and velocity fields for clamped circular plates in plastic limit state are derived with respect to the unified strength theory proposed by Yu.

Dynamic buckling of cracked circular arch with initial geometric imperfection subject to radius impact;

The stability equations of circular arch are obtained by the method of functional extremum.

By adopting the method of functional extremum analysis, the author derives the stability equation for section function and flexure function of circular arch.