Experimental and Theoretical Study of Metallic Hollow Sphere with Medium Thick Wall

Metallic hollow sphere (MHS) material is a new type of cellular material characterized by super-light, high specific stiffness and strength, the ability to absorb noise and energy, thermal insulation. It had been widely used in engineering, i.e. automobile, aircraft, civil and military. The basic unit of MHS cellular material was small metallic hollow sphere in macro, and the instability of sphere shell is always the most difficult problem in mechanical field. In this paper, we explored the internal factors and the principle of this phenomenon though the methods of theoretical and experimental. The equation of deformation of MHS was derived. It had shown that the nominal strain was related to the radius of the shell and loads, and the nominal stress was connected with the radius, load and the thickness of shell wall. A series of quasi-static uniaxial compression tests were progressed for a group of single MHSs, which radii were 4mm, 5mm and 7mm. It was found that the deformation planes are circle and symmetry both top and bottom, and the curves of nominal stress-strain were similar to a half parabola. There was a perfectly uniformity of the theoretical model and the experimental results.