Study On The In-plane Dynamic Stability Of The Deep Arch Under The Concentrated Periodical Exciting Force

With the development of modern science and technology, structure is increasingly using high strength material and thin-walled type, more and more to develop in the direction of light large-span, structural stability problem increasingly exposed, which directly affect people’s life and property safety. In this paper, by means of theoretical analysis, combining numerical calculation and model test, the dynamic stability of deeparch whose arch ends are by consolidation under concentrated periodical exciting force is studied:(1)The equation of dynamic stability of deep arch is deduced. According to the dynamic characteristics of deep arch structure, Abstracting the in-plane instability mechanics schema of vault under the action of concentrated periodical exciting force, Set the corresponding displacement deformation function, and based on the existing hydraulic deep arch structure of static bending differential equations, introduced the inertial force, according to the theory of Kirchhoff equation, bending vibration differential equations of circular arc deep arch is deduced, Then using Hamilton variational principle and the galerkin method, consolidation deep arch mathieu-hill equation is deduced; Through the MATLAB programming mathieu-hill equation, deep arch in-plane dynamic stability boundary is obtained, the distribution structure dynamic unstable region is mapped.(2)Vibration test of deep arch structure dynamic stability model is finished. Designing deep experimental model arch of the different rise-span ratio and different weight, through vibration experiment test, and analyzing the dynamic instability process on the deep arch test model, tracking the dynamic buckling equilibrium path and the deformation process of the instability, to reveal the dynamic instability mode of deep arch under vertical periodical exciting force, to verify the correctness of the dynamic instability domain of theory in this paper, and the relationship between dynamic stability domain and frequency of vibration load.(3)Analysis of dynamic instability parameters of arch structure is carried out. Analyzing the dynamic stability effect of deep arch rise span ratio and vault weight. The results of the study shows that: Under the same conditions, with the increase of the ratio of rise to span, the frequency of structure parametric resonance decreased, and then dynamic unstable region is narrowing; Also, with the increase of vault counterweight the frequency of deep arch structure of parameter resonance is also gradually falling, the dynamic instability region is also gradually narrowing; Rise-span ratio and weight are the important factors of influencing the structural buckling mode,the vibration parameters frequency of arch structure is 2 times than the frequency of the external exciting force.