A Box Beam Testbed Structure for Evaluating Elastic Tailoring With Composites

Elastic tailoring refers to the use of composite materials to create structures with passive self-deformation control. These structures often exhibit globally coupled modes of deformation which are unusual. Examples are bend-twist and extension-twist in beam-like structures. Illustrations are presented which show that tailored configurations must be examined with care. If the structure is optimized for a particular mode of behavior, such as bend-twist or extension-twist, and is subjected to secondary loads of an unanticipated type, unwanted or unexpected behaviors may result which can significantly alter response. Situations such as this may be avoided by choosing configurations free of undesirable elastic couplings. One such configuration is the box beam model advocated as a testbed in the present paper.