Advanced Materials and Structures: Analysis Methods and Results

Abstract

Advanced and innovative materials are used increasingly in civil and aerospace engineering. To meet the demands of advanced materials in structural applications, novel analytical and experimental techniques have been developed to simulate and characterize the material responses and structural behaviors. To this end, this special issue of the Journal of Aerospace Engineering aims to present a collection of invited papers concerning the analytical and experimental techniques for advanced and emerging materials and structures in civil and aerospace engineering. The papers selected for this issue are primarily based on the presentations delivered in the three “Advanced Materials in Structures” sessions organized by the ASCE Aerospace Division’s Committee on Advanced Materials and Structures at the 44th AIAA/ASME/ASCE/AHS/ACS Structures, Structural Dynamics, and Materials (SDM) Conference, Norfolk, Va., April 7–10, 2003. Seven papers based on the presentations have been peer reviewed and are included in this special issue. Among them, a wide range of analytical and experimental techniques are covered, ranging from constitutive modeling, to advanced numerical simulation, and to novel experimental characterization of composite materials and novel structural systems. The papers address critical issues in the rapidly growing fields of civil/aerospace materials and structures, including application of advanced materials (e.g., braided composites and coating materials), novel structures (e.g., sinusoidal core configuration and z-pin reinforcement), advanced experimental methods (e.g., ballistic impact tests), as well as analytical/numerical techniques (e.g., the nonlinear, strain ratedependent constitutive models and linear time-dependent acoustic wave propagation) in support of test methods and applications. In most papers, a balanced approach of analytical, numerical, and experimental correlations is adopted, and their advancement to the state of the art in advanced materials and structures is illustrated. In “Ballistic Impact of Braided Composites with a Soft Projectile,” Roberts et al. experimentally investigate the impact behaviors of aluminum plates, braided composite plates, and braided composite half-rings subjected to a soft gelatin projectile. The failure modes are identified, and an estimate of the penetration threshold is provided, which is useful for damage-tolerance evaluation of aerospace components (i.e., fan cases in commercial jet engines) under impact of high-strain energy density. Ivancic and Palazotto’s “Experimental Considerations for Determining the Damping Coefficients of Hard Coatings” characterizes the dynamic behavior of a titanium plate coated with magnesium aluminate spinel, representing a turbine compressor blade. Various experimental tests using dynamic ping and laser vibrom-