J Mater sci(2008)43:6747-6757 knowledge on the structure and properties of the micro- pivotal importance for the control of the reliability and and nano-scale interphases in polymer composites and the performance of multiscale FRC structures. There seems to methodologies for their modeling in order to provide be general agreement on using continuum mechanics means for bridging the gap between continuum and dis- models to account for interphase phenomena from macro- crete models useful for reliable design of future multiscale to micro-scale and the design schemes based on continuum hierarchical composite structures mechanics, variational principles or Finite Element Anal The design of multi-length-scale composite structures, ysis(FEA) have been validated [2]. The understanding of such as the fuselage of the Boeing 787(Fig. 1), represents the translation of the properties of the micro-scale inter the state-of-the-art engineering application of fiber rein- phases into the response of macroscopic FRC parts is far forced composites(FRCs). These large structures are less unambigious [9]. The greatest success have been designed from top to bottom using continuum mechanics achieved in understanding and modeling of the role of the methodologies and the transitions between the individual micro-scale interphase in the stress transfer from the matrix treated simply with down the to a single fiber structural features of the greater length scale. Such multi- attempts to transfer properties of the micro-scale interphase scale continuum mechanics modeling approach was in the performance of a multi-fiber FRC structures have demonstrated to provide reasonable means for transforming generally failed the mechanical response of polymer composites accross Over the last 20 years, substantial advances were made several length and time scales from macro- down to micro- in understanding the deformation behavior of hard tissues scale(Fig. 2)[8]. such as bones which can also be considered multiscale Since the FRCs exhibit heterogeneous structure at functionally hierarchical composite structures(Fig 3)[71 multiple length scales, the interphase phenomena are of Unlike the FRC fuselage, bone is designed bottom-up MACRO MESO mm MICRO NANO 10n micro-and nano-length scales considered in this review Fig. 1 Part of the fuselage of Boeing 787 Dreamliner can serve as an top-bottom methodology within the framework of continuum example of a large manmade multiscale composite structure. This mechanics. No functional hierarchy exists between the various length polymer composite structure has been designed using the engineering scales 2 Springerknowledge on the structure and properties of the micro￾and nano-scale interphases in polymer composites and the methodologies for their modeling in order to provide means for bridging the gap between continuum and dis￾crete models useful for reliable design of future multiscale hierarchical composite structures. The design of multi-length-scale composite structures, such as the fuselage of the Boeing 787 (Fig. 1), represents the state-of-the-art engineering application of fiber rein￾forced composites (FRCs). These large structures are designed from top to bottom using continuum mechanics methodologies and the transitions between the individual length scales are treated simply with scalling down the structural features of the greater length scale. Such multi￾scale continuum mechanics modeling approach was demonstrated to provide reasonable means for transforming the mechanical response of polymer composites accross several length and time scales from macro- down to micro￾scale (Fig. 2) [8]. Since the FRCs exhibit heterogeneous structure at multiple length scales, the interphase phenomena are of pivotal importance for the control of the reliability and performance of multiscale FRC structures. There seems to be general agreement on using continuum mechanics models to account for interphase phenomena from macro￾to micro-scale and the design schemes based on continuum mechanics, variational principles or Finite Element Anal￾ysis (FEA) have been validated [2]. The understanding of the translation of the properties of the micro-scale inter￾phases into the response of macroscopic FRC parts is far less unambigious [9]. The greatest success have been achieved in understanding and modeling of the role of the micro-scale interphase in the stress transfer from the matrix to a single fiber in model composites [2–4, 8]. However, attempts to transfer properties of the micro-scale interphase in the performance of a multi-fiber FRC structures have generally failed. Over the last 20 years, substantial advances were made in understanding the deformation behavior of hard tissues such as bones which can also be considered multiscale functionally hierarchical composite structures (Fig. 3) [7]. Unlike the FRC fuselage, bone is designed bottom-up Fig. 1 Part of the fuselage of Boeing 787 Dreamliner can serve as an example of a large manmade multiscale composite structure. This polymer composite structure has been designed using the engineering top–bottom methodology within the framework of continuum mechanics. No functional hierarchy exists between the various length scales 6748 J Mater Sci (2008) 43:6747–6757 123