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 new structural paradigms are required. The new exotic structures have to provide higher performances, unatta- able bytheclassical structures builtof traditional materials. Theadvent of advanced composite materials, of smart materialsandfunctionally graded - terials (FGMs), have constituted the strongest stimuli for suchdevelopments. Moreover, their incorporation is likely to expand the use and capabilities of thin-walledbeam structures. Thenew and stringent requirements imposed on aeronautical/aerospace, turbomachinery and shaft structural systems will be best met by such new types of material structures.