AFloat 2021: American Floating Offshore Wind Technical Summit

Email invitation to the AFloat 2021: American Floating Offshore Wind Technical Summit scheduled for September 8 and 9, 2021. Due to the emergence of COVID variants and the health risks they pose, a decision was made to hold the event virtually to ensure everyone\u27s safety

Dr. Habib Dagher testifying before the U.S. Senate

Sen. Collins asks Dr. Habib Dagher about sustainable infrastructure solutions

Support the next generation by sponsoring the 2024 Windstorm Challenge!

The Windstorm Challenge is a unique opportunity for middle and high school students to get hands-on engineering practice at the Advanced Structures and Composites Center (ASCC). Organized by the same team that brings you AFloat, the Windstorm Challenge seeks to educate the next generation of floating offshore wind innovators

Life cycle assessment of nanocellulose-reinforced advanced fibre composites

The research and development of nanocellulose-reinforced polymer composites have dramatically increased in the recent years due to the possibility of exploiting the high tensile stiffness and strength of nanocellulose. In the work, the environmental impacts of bacterial cellulose (BC)- and nanofibrillated cellulose (NFC)-reinforced epoxy composites were evaluated using life cycle assessment (LCA). Neat polylactide (PLA) and 30% randomly oriented glass fibre-reinforced polypropylene (GF/PP) composites were used as benchmark materials for comparison. Our cradle-to-gate LCA showed that BC- and NFC-reinforced epoxy composites have higher global warming potential (GWP) and abiotic depletion potential of fossil fuels (ADf) compared to neat PLA and GF/PP even though the specific tensile moduli of the nanocellulose-reinforced epoxy composites were higher than neat PLA and GF/PP. However, when the use phase and the end-of-life of nanocellulose-reinforced epoxy composites were considered, the “green credentials” of nanocellulose-reinforced epoxy composites were comparable to that of neat PLA and GF/PP composites. Our life cycle scenario analysis showed that the cradle-to-grave GWP and ADf of BC- and NFC-reinforced epoxy composites could be lower than neat PLA when the composites contains more than 60 vol.-% nanocellulose. Our LCA model suggests that nanocellulose-reinforced epoxy composites with high nanocellulose loading is desired to produce materials with “greener credentials” than the best performing commercially available bio-derived polymer

Alfond W2 Ocean Engineering Lab

The Alfond W2 Ocean Engineering Lab at the University of Maine Advanced Structures and Composites Center is a unique facility equipped with a high-performance rotatable wind machine over a multidirectional wave basin. The facility will accurately simulate towing tests, variable water depths, and scaled wind and wave conditions that represent some of the worst storms possible anywhere on Earth

Effect of Chemically Modified Banana Fibers on the Mechanical Properties of Poly-Dimethyl-Siloxane-Based Composites

The study presents the mechanical properties of polymer-based composites reinforced with chemically modified banana fibers, by alkalization in different concentrations of sodium hydroxide (NaOH). The fiber weight fraction has a great effect on the mechanical properties of the composites. Stiff composites were obtained at 6 wt% fiber fractions with Young’s modulus of 254.00 ±12.70 MPa. Moreover, the yield strength was 35.70 ±1.79 MPa at 6 wt% fiber fractions. However, the ultimate tensile strength (UTS) and toughness of the composites were obtained at 5 wt% fiber fractions. Statistical analyses were used to ascertain the significant different on the mechanical properties of the fibers and composites. The implication of the results is then discussed for potential applications of PDMS-based composites reinforced with chemically modified banana fibers

Metal-metal reinforced laminar composites

Two prototype laminar composites have shown potential for high strength and high temperature applications. These composites might be made with less in-place anisotropy and be less expensive than comparable fiber composites

Regeneration of thermally recycled glass fibre for cost-effective composite recycling : Performance of composites based on PP and Recovered glass fibre

Due to economic and technical reasons, no recycling process for glass fibre composites has been commercialized on a large scale. Thermal recycling processes are promising in terms of potential for commercialization but the reinforcement potential of thermally recycled fibres is too low for the application in composites. In the present study, glass fibres were exposed to elevated temperatures prior to composite processing to imitate a thermal recycling process. The exposure of the fibres to elevated temperatures prior to composite processing caused a significant reduction of the mechanical properties of the composites. The heat treated fibres were regenerated with a post treatment. The regeneration of the glass fibres recovered the mechanical properties of the composites almost completely. Thus, this study shows that composites based on thermally recycled glass fibres have the potential to compete with composites based on ‘new’ glass fibres

Viscoelastic Fracture of Biological Composites

Soft constituent materials endow biological composites, such as bone, dentin and nacre, with viscoelastic properties that may play an important role in their remarkable fracture resistance. In this paper we calculate the scaling properties of the quasi-static energy release rate and the viscoelastic contribution to the fracture energy of various biological composites, using both perturbative and non-perturbative approaches. We consider coarse-grained descriptions of three types of anisotropic structures: (i) Liquid-crystal-like composites (ii) Stratified composites (iii) Staggered composites, for different crack orientations. In addition, we briefly discuss the implications of anisotropy for fracture criteria. Our analysis highlights the dominant lengthscales and scaling properties of viscoelastic fracture of biological composites. It may be useful for evaluating crack velocity toughening effects and structure-dissipation relations in these materials.Comment: 18 pages, 3 figure

Selected Research and Development Projects

Promotional flyer with summaries of a selection of research and development projects including VolturnUS 1:8, DeepCLiDAR, Composite Arch Bridge System, MAKO, Secure Hybrid Composite Shipping Container, Modular Ballistic Protection System, and NASA HAID