Model-based systems engineering approaches to chemicals and materials manufacturing

Model-based systems engineering (MBSE) is part of a long-term trend toward model-centric approaches adopted by many engineering disciplines. We establish the need of an MBSE approach by reviewing the importance, complexity, and vulnerability of the U.S. chemical supply chains. We discuss the origins, work processes, modeling approaches, and supporting tools of the systems engineering discipline (SE) and discuss limitations of the Process Systems Engineering (PSE) framework. We make the case for MBSE as a more generalizable approach. We introduce systems modeling strategies for MBSE, and a novel MBSE method that supports the automation tailored and extended to support the analysis of chemical supply chains. We demonstrate a specific use case of this method by creating a systems model for the manufacturing of an active pharmaceutical ingredient, Atropine. We conclude with a prospectus on developmental opportunities for extracting greater benefit from MBSE in the design and management of chemical supply chains.     

Mode I interlaminar fracture toughness of Nylon 66 nanofibrilmat interleaved carbon/epoxy laminates

Carbon/epoxy laminates interleaved with laboratory scale electrospun Nylon 66 nanofibrilmat and spunbonded nonwoven mats were investigated. The effect of the nanoscale fibers on the fracture toughness of the composite under pure Mode I loading was evaluated. It was shown that the nanofibrilmat is responsible for a major interlaminar fracture toughness improvement, as high as 255–322%, compared to a noninterleaved carbon/epoxy reference laminate. We further studied the improvement mechanism of the electrospun nanofibrilmat compared to a commercial spunbonded nonwoven Nylon 66 mat. A combination of two interlayer fracture mechanisms responsible for the toughness improvement is suggested: the first is related to the high energy dissipated by bridged thermoplastic nanofibers and the second is attributed to the generation of a plastic zone near the crack tip. The interlaminar fracture mechanisms of both electrospun nanofibrilmat and the nonwoven mat interleaving was analyzed and discussed. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers