The University of Texas at Arlington (UTA) has recently created the Advanced Materials and Structures Lab (AMSL) under the leadership of Professor Andrew Makeev. AMSL is becoming a focal, world class organization with a critical mass of researchers empowered by state-of-the-art facilities. The developed innovative approach enables a fundamental shift from relying on the traditional time-consuming trial and error experimentation loops and empiricism in the design of composite materials and structures, to efficient diagnostics and prognosis methods. These rely upon three-dimensional imaging and performance prediction based on accurate computational tools.
The fundamental shift from reliance on the traditional trial and error experimentation loops, to efficient diagnostics and performance prediction is needed in many engineering, biological, and medical applications. One example is the critical need in more durable composite materials for warfighting aircraft flight-critical components and structure. The efforts to develop analysis techniques capable of predicting the life of aircraft composite structures by the materials and structures research communities in academia, government labs, and industry were not successful during the last few decades. This is due to poor understanding of the complexity and interaction of failure modes in composite structures. AMSL researchers, in collaboration with Bell Helicopter Textron under the ONR project, Integration of Design and Manufacturing Processes to Improve Performance of Composites, have unequivocally demonstrated that inherent variability of the manufacturing processes of composite parts introduces defects which affect their structural performance. The analysis technology being developed at AMSL is able to (1) capture the material structure geometry including anomalies such as manufacturing defects in three dimensions; (2) measure all key mechanical properties associated with their highly-anisotropic structure using the minimum number of tests; and (3) transfer the material topography and properties into a multi-scale structural analysis model that captures multiple, interacting failure modes dominated by the building blocks of the composite material system. It is not the individual elements of the analysis technology but their integration that enables the breakthrough in the development of an infrastructure to accelerate the pace of discovery and deployment of the advanced composite materials and structures in the United States to achieving global competitiveness in the 21st century.
Recent advancement in nondestructive measurement, including the development of efficient and accurate micro-focus computed tomography system technologies, and strong improvement in computing power enables an efficient integration of all key elements of the material characterization into accurate computational tools. Such tools allow for basic reliance on analysis leading to significant reduction of costly experimental iterations. In particular, some of the experiments could potentially be performed virtually based on simulations.
In summary, the development of advanced materials and their application can be accelerated through the integration of high-fidelity three-dimensional nondestructive measurements; experimental methods to determine the key material properties; and computational techniques which rely on the measured material structure and the key material properties to predict lifetime performance for a diverse range of applications.
The potential benefits of the ability to accurately measure the material structure and transfer such non-destructive measurement into structural failure models are tremendous. The most recent milestone in the ONR program at UTA includes the development of experimental and analytical techniques to capture the effects of porosity on the interlaminar failure of composites. Historically, industry has been relying on porosity volume based metrics to reject or accept a composite part. However, the AMSL work shows that it is not only the porosity volume but also the location and the size of the individual voids in critical locations of the composite structure define the susceptibility to delamination failure. The AMSL work shows that fidelity of the non-destructive inspection needed to quantify the smallest voids that would impact structural performance becomes extremely important. Once the engineers know the part condition, e.g. critical defect location and size as well as the implications of such defect on the residual capability and useful life of the composite structure, the long-desired fundamental shift from the statistics-based to condition-based structural substantiation and disposition decisions will become a reality.
In addition to the ONR program, AMSL researchers are working on a number of projects in materials and structures. In particular, Professor Makeev represents the UT Arlington in the Vertical Lift Consortium, a national organization comprised of the U.S. rotorcraft industry and academic institutions involved in the vertical lift aircraft research with the common goal of providing long-term advancement of rotorcraft. He leads the Advanced Materials Technology Research at VLC and participates in a number of other VLC efforts including the durability and damage tolerance and the condition based maintenance technology. Professor Makeev also represents UT Arlington in the Vertical Lift Research Center of Excellence, a multi-university organization funded by the U.S. Army to conduct fundamental research in the rotorcraft areas.
AMSL research staff includes well-experienced and reputable faculty transferred from Georgia Institute of Technology, and top graduate students. The AMSL experimental facilities are rapidly expanding. The most recent equipment acquisitions include a state-of-the-art Computed Tomography facility from North Star Imaging; and high-resolution and ultra-high speed Digital Image Correlation facilities from Correlated Solutions with Allied Vision Prosilica GE4900 and Shimadzu HPV-2 camera systems.
Makeev, A. (2013) Interlaminar Shear Fatigue Behavior of Glass/Epoxy and Carbon/Epoxy Composites, Composites Science and Technology, 80 (2013), pp. 93–100.
Nikishkov, Y., Makeev, A., Seon, G. (2013) Progressive Fatigue Damage Simulation Method for Composites, International Journal of Fatigue, 48 (1), pp. 266-279.
Nikishkov, G., Nikishkov, Y., Makeev, A. (2013) Finite Element Mesh Generation for Composites with Ply Waviness based on X-Ray Computed Tomography, Advances in Engineering Software, 58 (2013), pp. 35-44.
Makeev, A., He, Y., Carpentier, P., Shonkwiler, B. (2012) A Method for Measurement of Multiple Constitutive Properties for Composite Materials. Composites: Part A, 43 (12), pp. 2199–2210.
He, Y., Makeev, A., Shonkwiler, B. (2012) Characterization of Nonlinear Shear Properties for Composite Materials Using Digital Image Correlation and Finite Element Analysis, Composites Science and Technology, 73 (2012), pp. 64–71.