A DCAMM seminar will be presented by
Associate Professor Qingda Yang
Dept. of Mechanical and Aerospace Engineering
University of Miami. Coral Gables, FL, USA
Abstract:
Composite materials are now widely used in many key areas such as aerospace, defense, and renewable energy, and off-shore pipelines. Recent high profile examples include the Boeing 787 dream-liners, ultra-light weight composite blades for wind mills, and multilayer FRPC-steel pipelines for deep-sea oil transportation. Multiscale hierarchical microstructures are usually integrated into such structures to achieve multi-functional purposes and/or to further gain the weight-savings.
However, the embedded microstructures pose significant challenges to the safety and durability of these structures. The complex material and structural response of such materials, especially the progressive damage evolution during service, have not been fully under-stood despite decades of extensive research. Costly and time-consuming experimental testing programs are currently needed to establish design allowables, and large safety margins have to be applied to cope with the associated uncertainties. Establishing practical yet high-accuracy analysis methods that can faithfully evaluate the safety and durability have become an issue of paramount importance.
This presentation will start with a brief introduction of the recent applications of such advanced composites with focuses on those gradually exposed damage/failure phenomena during their usage. The urgent need for efficient multiscale analyses methods that can explicitly resolve the small scale discrete damage events and can quantify their direct effects on structural integrity will become apparent. This will be followed by a brief review of existing methods based on continuum damage mechanics (CDM), linear, and nonlinear fracture mechanics. A newly developed augmented finite element method (A-FEM) for high-fidelity failure analyses of heterogeneous materials will then be introduced. Successful examples using the A-FEM to predict the progressive failure processes in several composite materials will be given to demonstrate the high-fidelity of the A-FEM. Finally a brief recount of a recent successful exercise of the virtual testing effort on a complex textile CMC material will be used to demonstrate the potential benefit of the virtual testing methodology.
Danish pastry, coffee and tea will be served 15 minutes before the seminar starts.
All interested persons are invited.