Sponsor Keynote Presentations

Keynote Title:

ONR Solid Mechanics Research: Composites and Sandwich Structures

Keynote Abstract:

Naval structures operate in severe environments, and are designed to withstand complex multi-axial loading conditions, including highly dynamic loadings. The effective design of these structures requires an understanding of the deformation and failure characteristics of structural materials, and the ability to predict and control their performance characteristics.

The Solid Mechanics Research Program at the Office of Naval Research provides the scientific basis for the effective design of affordable Naval structures. Today, the major focus is on mechanics of marine composite materials and composite sandwich structures. The program deals with understanding and modelling the physical processes involved in the response of glass-fiber and carbon-fiber reinforced composite materials and composite sandwich structures to static, cyclic, and dynamic, multi-axial loading conditions, in severe environments (sea water, moisture, temperature extremes, and hydrostatic pressure).

An overview will be provided of this Navy-unique research program, with a discussion of its objectives, research issues, recent accomplishments, and future directions. Topics discussed will include: effect of sea water on marine composites, and composite sandwich structures; long-term durability of marine composites; size effects in failure of composite sandwich structures; fatigue behaviour of woven and knitted fabric composites; impact damage in sandwich structures; effect of impact damage on fatigue; strain rate effects in marine composites; dynamic fracture of interfaces; dynamic interaction effects in multiple delaminations; fatigue of foam core used in sandwich structures; and concepts for mitigating impact damage in sandwich structures.

Research is also conducted into methods for the enhancement of mechanical/physical properties and for the introduction of multi-functionality to composite structures, through the use of nanoparticles. Future directions of research in mechanics of marine composites and sandwich structures will be discussed, including shock and blast effects on composite structures.