Mechanical Properties of Topologically Lightweight Conical Components Fabricated by Laser Additive Manufacturing
LIN Kaijie1, 2, WU Libin1, 2, YANG Jiankai1, 2, ZHANG Han1, 2, GU Dongdong1, 2
1. Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
2. Jiangsu Provincial Engineering Laboratory for Laser Additive Manufacturing of High-Performance Metallic Components, Nanjing 210016, China
Abstract:Aerospace lightweight structures usually need to meet various performance requirements, such as weight reduction, load-bearing, shock absorption and impact resistance. However, the weight reduction of structures is often accompanied by the reduction of load-bearing and impact resistance. In this paper, the topology optimization design of conical structures was carried out based on variable density method. And the integrated forming of conical lightweight components was realized by laser powder bed melting technology. The inflfluence mechanism of wall thickness on the mechanical properties of topologically optimized components under axial compression were studied. As the wall thickness increased from 1.0 mm to 3.0 mm, the specifific energy absorption increased fifirstly and then decreased. The component with wall thickness of 2.5 mm exhibited the highest specifific energy absorption, which was 11.48 J/g. The stress distribution during compression was studied by fifinite element simulation, which showed that the main reason for the buckling and fracture of structures was the large in plane compressive stress. The difffference of stress levels between the inner and outer walls led to the buckling deformation of the structure in difffferent directions. And with the increase of wall thickness, the stress concentration at the top of the cone and the reduction of the upper buckling degree terminated the continuous increase of energy absorption.