Manufacturing and Optimization Strength and Stiffness of Novel Lightweight Spheres Sandwich Structure by Carving Wax Method

Abstract

Sphere Sandwich Structures (SSS) are a new structure which may have the potentials to provide the energy absorption as compared with monolithic specimen material. By using carving wax plate, fifteen specimens have been prepared according to RSM optimize method and it machined by CNC-3axis machine with sphere end screw.Three variables sphere diameter(D), distance between spheres(X) and skin thickness(K) have has been studied. The relative density of the samples has been calculated and compared with the reference sample Monolithic, the lowest relative density is 0.35, 65% which is lower than the monolithic sample. The bending test has been achieved bythree-pointtest on the designed samples. The sample 603 has the highest stress value and an improvement of 62% compared with the reference sample. The optimal value of this test is 19.35 Mpa2/3 of the sample 602 (diameter = 6, distance between spheres = 0, skin thickness = 2 mm).The stiffness has been calculated by known the modulus of elasticity of the designed samples, it is known as the Performance Index. The specimen 642has the highest modulus value and the improvement 116% compared with the reference sample, the optimal value for this test is 2.28 Gpa0.5 for sample 602 (diameter = 6, distance between spheres = 0, skin thickness = 2 mm).