Responses of damage and energy of sandwich and multilayer beams composed of metallic face sheets and aluminum foam core
- PDF / 784,770 Bytes
- 15 Pages / 612 x 792 pts (letter) Page_size
- 81 Downloads / 210 Views
WITH low density, high strength to weight ratio, and energy absorption capabilities for acoustic wave and impact loading, Alporas and Alulight, aluminum foams made by casting and powder metallurgical methods, respectively, have been increasingly expected to replace polymer and to be used as structural material for panels and shells in various industrial, aerospace, and automotive fields. Mechanical properties and constitutive mode of deformation of monolithic aluminum foam have been described by practical experiments[1–3,6–10,15–17] and theoretical analysis of honeycomb structure.[4,5,11–14] It has been suggested that relative density r9 of the foam (defined as ratio of bulk foam density rbf to cell wall density rcf) plays a key role in the mechanical response of aluminum foams. In reality, independent application of the aluminum foam as panels and shells is scarce. The potential for the aluminum foam extensive application is as core of sandwich or multilayer beams with solid face sheets. The purpose of sandwich or multilayer beams design is to improve the low stiffness of the monolithic foam but to maintain the low density of the J.B. SHA, Associate Professor, is with the School of Materials Science & Engineering, Bei Hang University, Beijing Haidian District, 100083, Beijing, People’s Republic of China. T.H. YIP, Assistant Professor, is with the School of Materials Engineering, Nanyang Technological University, Singapore, 639698. JUN SUN, Professor, is with the The Key State Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, People’s Republic of China. Manuscript submitted June 21, 2004. METALLURGICAL AND MATERIALS TRANSACTIONS A
entire beam. In considering the applications in structure and energy absorption areas, the mechanical response of sandwich beams composed of aluminum foam core and solid face sheets under static stress situation is a prior issue and is of increased concern. Under bending conditions, failure of sandwiches composed of foam core and aluminum alloy face sheets is classified into three modes: face yield, indentation, and core shear.[18,19,20] Bart-Smith et al.[18] and Chen et al.[19] have discussed a mechanism map showing failure domains of each mode by simplifying limit load criteria. The map directly displays the tight influence of the geometrical parameters of the beams on the failure modes. The predictions are in good agreement with experimental results and finite element analysis under bending fracture and fatigue conditions. However, the boundaries of the failure regions are variable for different face sheets; for any new selected face sheets, the boundaries of the failure regions in these maps must be recalculated. Due to the negligible literature about sandwich with aluminum foam core, various kinds of face sheets such as metals[18,19,20] and ceramics[25] should be assembled with aluminum foam to probe the potential of sandwich application, because the face sheet dominates the behavior of the core and the
Data Loading...
