There has been a growing interest in the foundation of the theory of th- walled composite beams and of their incorporation in aeronautical/aerospace, automotive, helicopter and turbomachinery rotor blades, mechanical,civil and naval constructions inthe last two decades or so. The proliferation of the specialized literature, mainly in the form of journal/ proceedings papers, and the activity in terms of workshops devoted to this topic attest this interest. A decisive factor that has fueled thisgrowing activity was generatedby highdiversity and severity ofdemandsand operating conditions imposed on structural elements involvedintheadvanced technology. In order to beable to survive andful?ll theirmission inthe extreme environmental conditions inwhich they operate, new materialsand