Study On Dynamic Buckling Of Functionally Graded Graphene Nanoplatelet Reinforced Composite Arches

Graphene has excellent thermal,electrical and optical properties,and has important application prospects in construction engineering,aerospace,biomedicine and energy.The theoretical Young’s modulus of graphene is as high as 1.0TPa,and a large number of studies have verified that adding graphene as a reinforcement material into the structural matrix material can improve the mechanical properties of the structure.In particular,graphene is added into the structure in the form of gradient to form a functional gradient graphene reinforced composite structure has also been recognized by the majority of researchers.However,there are few researches on the structure of functionally graded graphene nanoplatelet reinforced composites,especially on functionally graded graphene nanoplatelet reinforced composite arches.Although there are abundant research results on the dynamics of arches,there are few researches on the dynamics of functionally gradient graphene reinforced composite arch.Considering that the arch may face a variety of dynamic load forms in the service process,the dynamic loads studied in this paper include rectangular pulse load,arbitrary radial load and drop load.The dynamic buckling of functionally graded graphene nanoplatelet arch under different dynamic loads is studied by combining finite element numerical simulation method and theoretical analysis.The specific research contents are as follows:(1)Finite element numerical modeling of functionally graded graphene reinforced composite arch was carried out.Then the dynamic displacement response of the arch is obtained by establishing the motion equation of the arch under rectangular impulse load using finite element method.By combining the nonlinear static equilibrium path of the arch and the peak displacement curve of the vault,the general principle of the finite element dynamic buckling judgment is obtained,and then the dynamic buckling critical load calculated by this method is compared with the analytical solution of theoretical formula method provided in literature.Finally,the influence of various parameters on dynamic buckling of arch is analyzed by using control variable method.(2)The motion equation of functionally graded graphene reinforced composite arch under arbitrary radial concentrated force was established by Hamiltonian principle.Then the total potential energy equation of the arch was established according to the conservation of energy theorem.Combined with the nonlinear static equilibrium equation and zero potential energy equation,the analytical solution of dynamic buckling critical load is derived.The dynamic response behavior of the arch under dynamic load is demonstrated by finite element numerical simulation,and the correctness of the theoretical formula is verified by comparing the general principle of the finite element dynamic buckling judgment with the theoretical formula.Finally,the critical value of parameters which can cause dynamic buckling of arch is determined according to whether the total potential energy curve reaches zero or not.(3)The nonlinear equilibrium equation and energy equation of functionally graded arch graphene reinforced composite arch under an impact load is established,and concrete analysis fall quality and quality drop height on the dynamic buckling critical load,the influence of according to dynamic buckling criterion for arch dynamic buckling critical load and load critical height,critical arch slenderness ratio,such as the critical value.Then,the effects of drop height,arch slenderness ratio,graphene mass fraction,cross-section graphene distribution pattern,arch size and arch center angle on dynamic buckling of arch under drop impact were analyzed in detail.