Approach to Analysis of Composite Structures Subjected to Action of High-Energy Laser Beam

The paper presents a methodology that can be employed in numerical and analytical analyses of composite plates subjected to the action of a laser beam. The problem is related both to protection of composite components of aerospace structures from hostile high-energy laser weapons as well as to drilling holes in composites using a laser. In both cases, a three-dimensional state of stresses in the vicinity of the focal spot (the contact zone where the structure-laser beam interaction takes place) has to be evaluated. In addition, if a hostile laser locks on a structure, it is necessary to estimate changes in the structural response during and after the interaction. The paper outlines the solution of the problem of local three-dimensional stresses as well as an approach to the global response analysis. Finally, a practical problem where local damage exists in the structure as a result of a limited exposure to a laser beam is discussed. Numerical examples illustrate that even a small indentation produced by a laser can noticeably affect the natural frequencies of a composite beam.