Advanced Materials and Structures Lab (AMSL)
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.
AMSL Director Professor Andrew Makeev.
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.
UTA/Bell Team working on the ONR project, Integration of Design and Manufacturing Processes to Improve Performance of Composites (left to right, Ms Carpentier, Dr. Nikishkov, Ms Bostaph, Mr Shonkwiler, Prof. Makeev, and Mr. Lee) after reviewing CT reconstruction results at the AMSL facility.
After a productive review at the CT facility, the UTA/Bell Team assembled in the AMSL conference center to summarize their discoveries of the effects of defects.
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.
More information about results of the ONR program is available in the ONR Innovation Newsletter, Breakthrough Technologies, Vol. 10, Spring 2013, which features an article by the ONR Aircraft Technology Program Officer Dr. Judah Milgram, Composite Structures, a View from the Inside (p. 32).
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 stereo camera systems. The CT facility has a micro-focus X-Ray tube; can handle parts up to 5 feet long; and includes an integrated load frame with 10 kip axial force capacity, developed under funding from the ONR.
Ph.D. candidate Paige Carpentier is conducting a short-beam test coupled with the digital image correlation (DIC) technique for the full-field three-dimensional measurement of surface deformation, to assess multiple nonlinear stress-strain constitutive properties essential for understanding complex deformation and failure mechanisms for a composite material.
Graduate student Ekaterina Bostaph is setting up a composite test article for a micro-focus CT scan to determine the material structure in three dimensions, including any manufacturing defects and delaminations resulting from a fatigue test.
Faculty research associate Dr. Yuri Nikishkov and Ms Bostaph are examining the CT scan reconstruction results for a composite test article after fatigue testing.
AMSL Director Professor Andrew Makeev and Dr. Yuri Nikishkov discovered multiple delaminations initiated at manufacturing defects in the fatigue tested article.
Selected Recent Publications
Makeev, A., Nikishkov, Y., Seon, G., Armanios, E. Effects of Defects on Interlaminar Performance of Composites, Proceedings of the 39th European Rotorcraft Forum, Moscow, Russia. Submitted to Journal of American Helicopter Society, 2013.
Makeev, A., Bakis, C., Strauch, E., Chris, M., Holemans, P., Miller, G., Spencer, D., Patz, N. Advanced Composite Materials Technology for Rotorcraft, Proceedings of the 39th European Rotorcraft Forum, Moscow, Russia. Submitted to Journal of American Helicopter Society, 2013.
Makeev, A., Seon, G., Nikishkov, Y., Lee, E., Methods for Assessment of Interlaminar Tensile Strength of Composite Materials, Accepted for Publication, Journal of Composite Materials, 2014.
He, Y., Makeev, A. (2014) Nonlinear Shear Behavior and Interlaminar Shear Strength of Unidirectional Polymer Matrix Composites: A Numerical Study, International Journal of Solids and Structures, 51 (2014), pp. 1263-1273.
Makeev, A., Carpentier, P., Shonkwiler, B. (2014) Methods to Measure Interlaminar Tensile Modulus of Composites, Composites: Part A, 56 (2014), pp. 256-261.
Seon, G., Makeev, A., Nikishkov, Y., Lee, E. (2013) Effects of Defects on Interlaminar Tensile Fatigue Behavior of Carbon/Epoxy Composites, Composites Science and Technology, 89 (2013), pp. 194-201.
Nikishkov, Y., Airoldi, L., Makeev, A. (2013) Measurement of Voids in Composites by X-Ray Computed Tomography, Composites Science and Technology, 89 (2013), pp. 89-97.
Seon, G., Nikishkov, Y., Makeev, A. (2013) Structural Analysis of Composites with Porosity Defects based on X-Ray Computed Tomography, Journal of Composite Materials, Published Online, July 15, 2013. DOI: 10.1177/0021998313494917
Makeev, A., He, Y. (2013) Short-Beam Shear Method for Assessment of Stress-Strain Curves for Fiber-Reinforced Polymer-Matrix Composite Materials, Strain (2013) 49, pp. 440-450.
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