A Grammatical Approach for Customization of Laminated Composite Materials

The wide range of properties covered by the manufacturable fiber—matrix combinations of composite materials, along with their directional property characteristics, provides designers with material selection flexibility during designing composite material products. Meeting multiple property goals, however, complicates the design process as both the composite material selection and the component shape formation becomes intricate with the multiple loading conditions, which may require matrix calculations of high order to determine theoretical value of composite material properties. This article presents a grammatical approach that is derived by extending shape grammars to simultaneously consider the shape of a component and select appropriate composite materials to meet multiple property goals, derived from a set of design loads. In this approach the grammar is divided into four interconnected steps, which are used to design the shape of the component depending on its function and user requirements, calculate the property requirements from the loading constraints based on the designed shape, and select composite materials according to the property requirements. Selection of composite materials involves determining the fiber and matrix, their volume fraction, number of plies, and ply orientations in different location of the load-bearing component. A hollow shape hip replacement joint is designed using composite material to illustrate the approach. Finite element analysis is performed to verify the design.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

A Virtual Testing Approach for Laminated Composites Based on Micromechanics

International audienceThe chapter deals with a crucial question for the design of composite structures: how can one predict the evolution of damage up to and including final fracture? Virtual testing, whose goal is to drastically reduce the huge number of industrial tests involved in current characterization procedures, constitutes one of today’s main industrial challenges. In this work, one revisits our multiscale modeling answer through its practical aspects. Some complements regarding identification, kinking, and crack initiation are also given. Finally, the current capabilities and limits of this approach are discussed, as well as the computational challenges that are inherent to “Virtual Structural Testing.

Damage in Composite Laminates: Effects of Transverse Cracks

Two different methods of solution are used to study the effects of transverse cracks in cross-ply composite laminates. The results of an approximate analytical solution are compared with those obtained using a finite element analysis in order to study the effects of transverse cracks on the degradation of elastic and thermal coefficients as well as stress distributions. In particular, it is shown that transverse cracks cause significant degradation of the Poisson's ratio and shear modulus of the laminates, and also affect some stress distributions in a peculiar manner. Theoretical results are compared with existing experimental results where appropriate. © 1988

2-D and 3-D Damage Effects in Cross-Ply Laminates

Theoretical results are presented showing that the degradation in Poisson's ratio and shear modulus are much more significant than the degradation in axial modulus for cross-ply laminates with transverse cracks in one or two orthogonal directions. Further, it is shown that Poisson's ratio varies significantly through the thickness of a cracked outer layer a cross-ply laminate