Department of Civil Engineering, Zhejiang University, Hangzhou, Zhejiang Province, 310027, P.R.C.
Abstract:
The equilibrium equations for elastic circular arches are established using the principle of virtual work. The nonlinear partial differential equations of motion are solved using a finite difference method (Park's method for time difference). The dynamic stability of a hinged and a clamped elastic circular arch with a uniform step load is analysed with finite deformations and initial geometric imperfections. Results show that the buckling mode varies with the value of the arch half angle, θ0. The boundary condition and initial imperfection amplitude also effect the buckling mode. A nearly perfect arch usually buckling with a “direct” buckling form, while an imperfect arch with an “indirect” buckling form. The effect of θ0 on the ratio pd/ps (pd is the dynamic critical load and ps the static critical load) is shown for different initial imperfections and different boundary conditions.