Advanced Mechanics and Materials Laboratory

The Advanced Mechanics and Materials Laboratory (AMML) is primarily involved in the computational modeling and thermo-mechanical characterization of high performance materials. In the AMML, we believe that there needs to be a paradigm shift from generating new materials purely through experimental methods to the use of computer models to effectively identify potential materials systems. We see this as the most ideal way to develop advanced materials to meet the increasing demands of future space and automotive applications in a timely fashion. The overall objective of the laboratory is to engineer novel materials by establishing relationships between material constituents and product performance and creating computer models thereof. The current areas of research include

• computational and experimental characterization of advanced materials including metal matrix composites,
• processing and characterization of polymeric matrix composites,
• processing and process modeling of superplastic materials,
• computational modeling of deformation mechanisms of superplastic materials
• design, analysis, and characterization of superconducting magnets and materials

The application of metal matrix composites has been severely hindered by a lack of understanding of the behavior of fiber-matrix interfaces. Recently, we have analyzed the interface failure process to extract interfacial properties from experimental results. We have developed analytical and computational models to understand the effects of processing on the origin of residual stresses in metal matrix composites. In the area of superplasticity, we have developed numerous process models for 2-D and 3-D configurations using simplified approaches and non-linear finite element methods. We have also developed a micromechanical model of superplastic deformation processes taking into account the grain to grain variation of properties. We have, in collaboration with aerospace industries, performed extensive mechanical characterizations of polymeric matrix composites to understand the effect of processing and test conditions on performance. Current efforts include consolidation of metal matrix composites and studies on the effect of processing on the evolution of interfaces with the objective of determining optimum interfacial conditions. The effects of microscopic damage on the performance of laminated composites will soon be explored using advanced computing techniques. Efforts are also underway to identify the existence of superplasticity in materials using a computational micromechanical approach which will significantly reduce the time required from the present trial and error approach.

The AMML is directed by Professor N. Chandra, and conducts joint research programs with the Supercomputer Computations Research Institute (SCRI), the National High Magnetic Field Laboratory (NHMFL), and the Materials Research and Technology Center (MARTECH). AMML is equipped with excellent facilities, including a highly automated Materials Testing System testing machine (MTS 810) with computerized data acquisition/control and high temperature testing capabilities. The program uses the latest in electron diffraction techniques, which involve a Scanning Electron Microscopy with a backscattered electron detector and a probe current detector (WDS and EDS) equipped with phosphor screen and camera complete with interfaces to transfer the image to a computer for image analysis. The laboratory has direct access to an X-ray spectroscope (with high temperature capabilities) and a high and low energy electron diffractometer. Thermomechanical processing facilities available within AMML include a 50T up-acting hydraulic press and a superplastic forming press with computer interface for pressure control and data acquisition.

The computational facilities include a network of dedicated workstations (VAX, Silicon Graphics, and Macintosh) with ample supporting hardware and software including many in-house numerical and graphics packages. There is a direct link to a supercomputer at FSU (a Silicon Graphics Power Challenge XL - a shared memory, multiprocessor machine that utilizes MIPS R8000 RISC CPUs with a peak speed of 3.6 GFLOPS).