Microstructure Analysis of Aluminum Alloy and Copper Alloy Circular Shells After Multiaxial Plastic Buckling

Aluminum and copper cylindrical shells were plastically buckled under quasi-static and dynamic loading conditions with an Absorption Compression-Torsion Plasticity (ACTP: Patent No. WO 2005090822) combined mechanical testing device. Optical microscopy and transmission electron microscopy (TEM) analysis were used to study the microscopic evolutions in the mechanically buckled aluminum and copper alloy samples. Optical microscopy showed evidence of the presence of second-phase particles in both the aluminum and copper alloys samples. Under dynamic loading aluminum samples showed more energy absorption as compared to copper samples. Material flow lines were more pronounced in the copper samples when observed by optical microscopy. The evidence that supports the increased energy absorption in the aluminum cylindrical shells can be supported by the TEM analysis more than the optical microscopy analysis. The TEM results showed highly oriented textured morphology with the presence of few dislocation cells structures and sub-structures

Analysis of Heat Effects on Marine Corps AM2 Mat Mechanical Properties

Navy AM2 mats are used as portable aircraft landing platforms for the Short Take-off/Vertical Landing (STOVL) aircraft operations. This investigation presents the study performed to determine whether the surface discoloration is a precursor to degradation in the mechanical property of the AM2 mat material. The red discoloration on the mat surfaces had a clear correlation with the decrease in yield strength, ultimate strength, and hardness properties