Hermal Buckling Study Of Metallic Glass Spheres

In recent years, people broke through the restriction on the size of metallic glass gradually and began to explore its mechanical properties with advances in technology. Metallic glass has a lot of good properties such as high elasticity, high yield strength and high hardness, and its good mechanical properties can significantly improve the performance and security of products, therefore they are widely used in military affairs, outer space, science and technology, sports, medical treatment and other fields.As one of the most common structures, spherical shell structure is used in various industries. The stability problem of a spherical shell is an important issue in practical application. Improving the stability of spherical shell and accurately predicting the spherical shell buckling critical pressure and critical temperature become main line of the researchers’studies, especially the thermal buckling problem. Due to its unique structural characteristics, metallic glass has some excellent properties that ordinary metals don’t possess. The spherical shell made up of metallic glass has a better ability to resist deformation than the traditional metal shell. The spherical shell stability is greatly improved. The thin spherical shell thermal buckling of metal glass material was studied in this paper and some valuable references to the thin spherical shell application of metallic glass material in engineering were provided.1、Isotropic linear elastic thermal constitutive equation was studied on the bases of the isotropic non-linear elastic complete thermal constitutive equation represented by tensor. The initial temperature and its increase value were considered in those thermal constitutive equations. Thermal constitutive equations of thick and thin spherical shell under plane stress state were obtained by using tensor methods.2、The stability equations of thin spherical shell deduced by Professor Li Chen using tensor methods was compared with the stability equation deduced by Timoshenko with the method of superposition principle. It was found that two equations were different. Superposition theorem was used to explain the differences between the two equations.3、Thermal buckling equation of thin spherical shell was deduced by the simultaneous equations of physical and geometric equation on the bases of axisymmetric thin spherical shell buckling equation which derived by tensor method considering the influence of film force on the shell under non-moment state. Thermal buckling equations considering uniform temperature and the coupling of uniform external pressure and temperature were expressed by displacement, respectively.4、Thin spherical shell buckling of minimum potential energy functional was established through the method of virtual work principle. Three thermal buckling problem of hemispherical shell which surrounding was simply supported was analysed by Ritz method. The following three conclusions were derived:(1) Critical load value of uniform external pressure was derived on the condition that temperature did not exceed the critical buckling temperature. (2) The buckling critical temperature value was derived on the condition the uniform external pressure load was zero. (3) Buckling critical temperature value was derived on the condition that uniform external pressure load did not exceed the critical load.