Affordable processing of thick section and integral multi-functional composites

The use of multi-functional integral armor is of current interest in armore d vehicles and military carriers. In the present study, thick-section lamin ated composites and multi-layered integrated composites have been processed /manufactured with the aim of providing multifunctionality including easy r eparability, quick deployment, enhanced ballistic damage and fire protectio n, as well as lightweight advantages. The design of an integral armor utili zes a combination of thick-section structural composite, ceramic tiles, res ilient rubber, fire retardant laminate liner and a composite durability cov er. Processing techniques such as automated fiber placement and/or autoclav e molding are traditionally used to process dissimilar multi-layered struct ure, but prove to be expensive. This work focuses on emerging cost-effective liquid molding processes such as vacuum assisted resin transfer/infusion molding (VARTM) for the producti on of thick-section and integral armor parts (up to 50 mm thick). While thi ck-section composites have applications in a variety of structures includin g armored vehicles, marine bodies, civil infrastructure, etc, in the presen t work they refer to the structural laminate within the integral armor. The processing steps of thick-section composite panels and integral armor have been presented. The integrity of the interfaces has been evaluated through scanning electron microscopy (SEM). Representative results on static and d ynamic response thigh strain rate, HSR and ballistic impact) of the VARTM p rocessed thick-section composite panels are presented. Wherever applicable, comparisons are made to conventional closed-mold resin transfer molding (C MRTM). Process sensing by way of flow and cure monitoring of the resin in t he fiber perform has been conducted using embedded direct current (DC)-base d sensors in the thick-section preform and integral armor interfaces. The f easibility of cost-effective VARTM for producing thick-section composites a nd integral armor has been demonstrated. (C) 2001 Elsevier Science Ltd. All rights reserved.