Dr. Frank Abdi Profile

Dr. Frank Abdi

Founder/CEO at AlphaSTAR Corp

SPIE Involvement:

Author

Proceedings Article | 31 March 2014 Paper

Test validation of environmental barrier coating (EBC) durability and damage tolerance modeling approach

Ali Abdul-Aziz, Ali Najafi, Frank Abdi, Ramakrishna Bhatt, Joseph Grady

Proceedings Volume 9058, 90580P (2014) https://doi.org/10.1117/12.2045914

KEYWORDS: Coating, Failure analysis, Thin film coatings, Finite element methods, Composites, 3D modeling, Tolerancing, Plasma, Silicon, Ceramics

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Proceedings Article | 31 May 2013 Paper

Damage tolerance modeling and validation of a wireless sensory composite panel for a structural health monitoring system

Mohamad Talagani, Frank Abdi, Dimitris Saravanos, Nikos Chrysohoidis, Kamran Nikbin, Rose Ragalini, Irena Rodov

Proceedings Volume 8720, 87200J (2013) https://doi.org/10.1117/12.2017382

KEYWORDS: Composites, Sensors, Failure analysis, Diamond, Structural health monitoring, Diagnostics, Finite element methods, Double positive medium, Skin, Seaborgium

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The paper proposes the diagnostic and prognostic modeling and test validation of a Wireless Integrated Strain Monitoring and Simulation System (WISMOS). The effort verifies a hardware and web based software tool that is able to evaluate and optimize sensorized aerospace composite structures for the purpose of Structural Health Monitoring (SHM). The tool is an extension of an existing suite of an SHM system, based on a diagnostic-prognostic system (DPS) methodology. The goal of the extended SHM-DPS is to apply multi-scale nonlinear physics-based Progressive Failure analyses to the “as-is” structural configuration to determine residual strength, remaining service life, and future inspection intervals and maintenance procedures. The DPS solution meets the JTI Green Regional Aircraft (GRA) goals towards low weight, durable and reliable commercial aircraft. It will take advantage of the currently developed methodologies within the European Clean sky JTI project WISMOS, with the capability to transmit, store and process strain data from a network of wireless sensors (e.g. strain gages, FBGA) and utilize a DPS-based methodology, based on multi scale progressive failure analysis (MS-PFA), to determine structural health and to advice with respect to condition based inspection and maintenance. As part of the validation of the Diagnostic and prognostic system, Carbon/Epoxy ASTM coupons were fabricated and tested to extract the mechanical properties. Subsequently two composite stiffened panels were manufactured, instrumented and tested under compressive loading: 1) an undamaged stiffened buckling panel; and 2) a damaged stiffened buckling panel including an initial diamond cut. Next numerical Finite element models of the two panels were developed and analyzed under test conditions using Multi-Scale Progressive Failure Analysis (an extension of FEM) to evaluate the damage/fracture evolution process, as well as the identification of contributing failure modes. The comparisons between predictions and test results were within 10% accuracy.

Proceedings Article | 11 April 2013 Paper

Environmental barrier coating (EBC) durability modeling using a progressive failure analysis approach part II

Ali Abdul-Aziz, Joseph Arias, Frank Abdi, Ramakrishna Bhatt, Joseph Grady, D. Zhu

Proceedings Volume 8693, 86930G (2013) https://doi.org/10.1117/12.2008490

KEYWORDS: Coating, Failure analysis, Thin film coatings, Finite element methods, Composites, Mechanics, Reverse modeling, Silicon carbide, Interfaces, Reverse engineering

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The need for a protecting guard for the popular Ceramic Matrix Composites (CMCs) is getting a lot of attention from engine manufacturers and aerospace companies. This is because the CMC has a weight advantage over standard metallic materials and more performance benefits. They are also commonly porous material and this feature is somewhat beneficial since it allows some desirable infiltration. They further undergo degradation that typically includes coating interface oxidation as opposed to moisture induced matrix which is generally seen at a higher temperature. Variety of factors such as residual stresses, coating process related flaws, and casting conditions may influence the degradation of mechanical properties of CMC. The cause of such defects which cause cracking and other damage is that not much energy is absorbed during fracture of these materials. Therefore, an understanding of the issues that control crack deflection and propagation along interfaces is needed to maximize the energy dissipation capabilities of layered ceramics. These durability considerations are being addressed by introducing highly specialized form of environmental barrier coating (EBC) that is being developed and explored in particular for high temperature applications greater than 1100 °C ^1-3. The EBCs are typically a multilayer of coatings and are in the order of hundreds of microns thick. Thus, evaluating components and subcomponents made out of CMCs under gas turbine engine conditions are suggested to demonstrate that these materials will perform as required especially when subjected to extreme temperatures and harsh operating environment. The need exists to use advanced computational methods to assess risk associated with exposure to high temperature of EBC coated CMC specimens. In the work presented here, multiscale progressive failure analysis (PFA) approach was used to evaluate the damage growth in the coating and CMC after exposure time to cyclic and elevated temperatures. In each cycle, the specimen was heated to 1300 °C then maintained at that temperature for a period of time before cooling it down to room temperature. The PFA evaluation was carried out with the GENOA⁴ software using integrated capability inclusive of: finite element structural analysis, micro-mechanics, damage progression and tracking, fracture mechanics, and life prediction. In this paper, reverse engineered constituent properties obtained from CMC lamina properties were used as input to PFA to evaluate the degradation of specimen strength during thermal cycling. The analysis results indicated that the damage initiated in the top coat of the EBC then propagated down to the bond before reaching the CMC. Life assessment of the CMC was carried out twice, once using micromechanics properties as input and another time using macromechanics properties. It was determined that the use macromechanics properties yielded a more conservative life prediction for the CMC specimen as compared to that obtained from the use of micromechanics with fiber and matrix properties as input. Residual stresses evaluated during cooldown supported the onset of damage in the top coat. All stages of damage evolution were captured with PFA including damage initiation and damage propagation. Details on the life prediction of EBC and CMC materials are discussed next.

Proceedings Article | 10 May 2012 Paper

Development of an in-situ wireless strain monitoring system and its integration with FEA SHM simulation models

K. Nikbin, F. Abdi

Proceedings Volume 8368, 83680I (2012) https://doi.org/10.1117/12.919829

KEYWORDS: Composites, Sensors, Finite element methods, Failure analysis, Structural health monitoring, Double positive medium, Diagnostics, Aerospace engineering, Bridges, Sensor networks

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Proceedings Article | 26 May 2011 Paper

Wireless/integrated strain monitoring and simulation system

Frank Abdi, R. Dutton, Tatsuya Takahashi, Cody Godines, Galib Abumeri

Proceedings Volume 8026, 80260G (2011) https://doi.org/10.1117/12.885331

KEYWORDS: Composites, Failure analysis, Sensors, Finite element methods, Structural health monitoring, Double positive medium, Aerospace engineering, Computer simulations, Diagnostics, Inspection

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This paper addresses the development and real time test validation of an integrated hardware and software environment that will be able to measure real-time in-situ strain and deformation fields using a state-of-the-art wireless sensor system to enhance structural durability and damage tolerance (D&DT), reliability via real-time structural health monitoring (SHM) for sensorized aerospace structures. The tool will be a vital extension of existing suite of structural health monitoring (SHM) and diagnostic prognostic system (DPS). The goal of the extended SHM-DPS is to apply a multi-scale nonlinear physics-based finite element analyses (FEA) to the "as-is" structural configuration to determine multi-site damage evolution, residual strength, remaining service life, and future inspection intervals and procedures. Information from a distributed system of wireless sensors will be used to determine the "as-is" state of the structure versus the "as-designed" target. The approach enables active monitoring of aerospace structural component performance and realization of DPS-based conditioned based maintenance. Software enhancements will incorporate information from a sensor network system that is distributed over an aerospace structural component. As case study DPS application a realistic composite stiffened panel representative of fuselage/wing components is selected. Two stiffened panels is manufactured and instrumented; a) embedded internally between composite layers, and b) surface mounted with wireless sensors; the second of which with an optimized sensor network. The panels will be tested in compression following low-velocity impact. The sensor system output will be routed and integrated with a finite element analysis (FEA) tool to determine the panel's, multi-site damage locations, and associated failure mechanisms, residual strength, remaining service life, and future inspection interval. The FEA model utilizes the web/internet based GENOA progressive failure analysis commercial software suite, durability and damage tolerance (D&DT), and reliability software capable of evaluating both metallic and advanced composite structural panels under service loading conditions. The approach utilizes a building block validation strategy, and real-time structural health monitoring system.

Proceedings Article | 20 April 2010 Paper

Diagnostic/prognostic health monitoring system and evaluation of Army composite bridge

F. Abdi, R. Miraj, A. Mosallam, R. Dutton

Proceedings Volume 7675, 767506 (2010) https://doi.org/10.1117/12.851820

KEYWORDS: Composites, Double positive medium, Bridges, Sensors, Failure analysis, Data archive systems, Fiber optics sensors, Data modeling, Optical fibers, Fiber Bragg gratings

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Proceedings Article | 29 April 2009 Paper

Wireless ZigBee strain gage sensor system for structural health monitoring

Hiroshi Ide, Frank Abdi, Rashid Miraj, Chau Dang, Tatsuya Takahashi, Bruce Sauer

Proceedings Volume 7314, 731403 (2009) https://doi.org/10.1117/12.819358

KEYWORDS: Sensors, Composites, Metals, Stars, Structural health monitoring, Electronics, Personal digital assistants, Computing systems, Telecommunications, Signal processing

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A compact cell phone size radio frequency (ZigBee) wireless strain measurement sensor system to measure the structural strain deformation was developed. The developed system provides an accurate strain measurement data stream to the Internet for further Diagnostic and Prognostic (DPS) correlation. Existing methods of structural measurement by strain sensors (gauges) do not completely satisfy problems posed by continuous structural health monitoring. The need for efficient health monitoring methods with real-time requirements to bidirectional data flow from sensors and to a commanding device is becoming critical for keeping our daily life safety. The use of full-field strain measurement techniques could reduce costly experimental programs through better understanding of material behavior. Wireless sensor-network technology is a monitoring method that is estimated to grow rapidly providing potential for cost savings over traditional wired sensors. The many of currently available wireless monitoring methods have: the proactive and constant data rate character of the data streams rather than traditional reactive, event-driven data delivery; mostly static node placement on structures with limited number of nodes. Alpha STAR Electronics' wireless sensor network system, ASWN, addresses some of these deficiencies, making the system easier to operate. The ASWN strain measurement system utilizes off-the-shelf sensors, namely strain gauges, with an analog-to-digital converter/amplifier and ZigBee radio chips to keep cost lower. Strain data is captured by the sensor, converted to digital form and delivered to the ZigBee radio chip, which in turn broadcasts the information using wireless protocols to a Personal Data Assistant (PDA) or Laptop/Desktop computers. From here, data is forwarded to remote computers for higher-level analysis and feedback using traditional cellular and satellite communication or the Ethernet infrastructure. This system offers a compact size, lower cost, and temperature insensitivity for critical structural applications, which require immediate monitoring and feedback.

Showing 5 of 7 publications

Conference Committee Involvement (6)

Photonic Applications for Aviation, Aerospace, Commercial, and Harsh Environments V

19 August 2014 | San Diego, California, United States

Photonic Applications for Aerospace, Commercial, and Harsh Environments IV

29 April 2013 | Baltimore, Maryland, United States

Photonic Applications for Aerospace, Transportation, and Harsh Environment III

23 April 2012 | Baltimore, Maryland, United States

Photonic Applications for Aerospace, Transportation, and Harsh Environment II

25 April 2011 | Orlando, Florida, United States

Photonics in the Transportation Industry: Auto to Aerospace III

5 April 2010 | Orlando, Florida, United States

Showing 5 of 6 Conference Committees

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