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This work deals with the development and investigation of self-reinforced polylactic acid (SRPLA) composites manufactured from two different nonwoven preforms with two different bicomponent filament architectures. The SRPLA nonwovens prepared via spun bonding technology have two different bicomponent filament architectures, that is, core-sheath, and islands in the sea. For the core-sheath filaments, spunbound nonwovens are compared with the dry-laid SRPLA nonwovens. The SRPLA nonwoven preforms are compression molded at three different mold temperatures to fabricate composite plates. The optimum mold temperature is identified based on the flexural properties and residual void volume fraction of composites. The flexural modulus and strength are about 38% and 50% higher than those of the pure PolyLactic Acid (PLA) matrix, respectively. The influence of bicomponent filament architecture on the mechanical performance of composites is negligible, whereas the nonwoven architecture leads to significant differences both in the residual void volume fraction and in the mechanical properties of composites. Finally, the mechanical properties of the SRPLA composites are compared with those of the conventional composites to prove their applicability to semi-structural parts. [ABSTRACT FROM AUTHOR]

The optimization of the couplings between LCM processes and structural performances by repeated numerical simulations is expensive in terms of the computational cost. In order to overcome this difficulty, we propose a semi-analytical modeling of RTM and CRTM processes. Various processing routes of CRTM are considered according to the combinations of different stages of resin injection and reinforcement compression. This article is composed of two parts. First, we present analytical and semi-analytical models concerning the CRTM process with an imposed compression speed, in order to explain the methodology of resolution for the other CRTM manufacturing routes by an imposed compression force. The problems related to different constraints imposed on the CRTM process (imposed fiber volume fraction, feasibility criteria of process, and mold strength) are analyzed and formulated, so that they can be taken into account a numerical optimization. In the second part, a new numerical modeling of CRTM process with reinforcement compression under a force was developed and a comparison with semi-analytical model carried out. Recent work in the literature [Merotte J, Simacek P and Advani SG. Flow analysis during compression of partially impregnated fiber perform under controlled force. Compos Sci Technol 2010; 70: 725–733.] about the analysis of resin flow during compression of partially impregnated fiber preform under controlled force, allowed us to explore another alternative of comparison. Finally, this approach is used to control the RTM and CRTM processes and it is applied to a series of parametric studies, considering the effects of part size and fiber volume fraction on the mold filling time. This study not only contributes to the optimization of the couplings between manufacturing processes and structure, but also provides a tool for the control of the CRTM and RTM processes. [ABSTRACT FROM AUTHOR]