Deformation of Stacked Metallic Sheets by Shock Wave Loading

The focus of the present work is to develop a deep understanding of deformation of stacked metal sheets with a series of different sequences by using shock wave loading. Here, experimental and numerical investigations of deformation of a single metal sheet of 1.5-mm and the stack of three metal sheets of 0.5-mm thickness of aluminum (Al), copper (Cu) and brass (Br) material were carried out. In the shock wave experiments, helium was used as the driving gas to produce a strong shock wave. Finite elements method (FEM) simulations on 3D-computational models were performed with explicit dynamic analysis, and Johnson-Cook material model was used. The obtained results from experiments of the outer diameter, thickness distribution, and dome height were analyzed and compared with the numerical simulations, and both the results are in excellent agreement. Moreover, for the same pressure load, due to lower inter-metallic friction in the stacked sheets compared to a cohesive property of the single sheet, an excellent deformation of stacked metallic sheets was observed. The results of this work indicated that the shock wave-forming process is a feasible technique for mass production of stacked metallic sheets as well as fabricating a hierarchical composite structure, which provides higher formability and smooth thickness distribution compared to a single material

Improvisation of Interfacial Bond Strength in Shape Memory Alloy Hybrid Polymer Matrix Composites

AbstractIn the present study, we report on a novel approach adopted for the improvisation of interfacial bond strength between shape memory alloy (SMA) and epoxy matrix in SMA hybrid composites. Methodologies such as surface roughening and chemical etching of SMA wires were performed before embedding them in epoxy matrix. A pull-out test has been performed to find out the improvement in load transfer between SMA and host matrix. Surface morphology of SMA wires after various surface treatments was observed under scanning electron microscope (SEM). Significant improvement, nearly 260%, in interfacial shear strength between SMA-Epoxy interfaces has been observed in case of specimens embedded with chemically etched SMA wire in comparison to the specimens with untreated SMA wire