Composites Engineering, Failure Analysis, and Non-Destructive Testing Consultant

Expertise

• Root cause and failure analysis of composite structures.
• Failure investigations and risk reduction for new product introductions.
• Quality control systems for composite manufacturing.
• Engineering of carbon fiber and cellulose nanofiber composites.
• Composite defect analysis and development of new structural materials.
• Classical mechanics, experimental mechanics, composites, smart materials, defects, and fracture mechanics.
• Industrial advanced materials.
• Effects of defects in composite structures.
• Sustainable composite materials.
• Full field non-destructive testing methods. Stress analysis, fracture mechanics, fracture and failure analysis.
• Testing composite structures for safety and developing composite materials for zero greenhouse emissions.
• Develop on-site non-destructive testing methods.
• Test program development and execution.
• Advanced materials characterization testing and development.
• Finite element analysis (FEA) and modeling.
• Mechanical behavior of materials, mechanical testing, mechanics of materials, and computational structural mechanics.
• Damage mechanics
• Carbons
• Continuum mechanics
• Laminated composites and Delamination

Experience

Independent Consultant, Present

Composites Engineering

• Structures
• New products
• Failure analysis and root Cause for; space exploration, aeronautical and consumer product sectors.
• Failure of carbon bicycles.

SpaceX, Hawthorne, California, Sr. Build Reliability Engineer, 2017 - 2018

• Identified and eliminate potential risks to Falcon 9 and Dragon 1st stage and 2 stage composite structures due to manufacturing defects. Root cause failure analysis resulted in systematic changes in planning and manufacturing procedure in lamination.
• Projects include FOD, out-time effects, wrinkles and porosity effects during manufacturing.
• Project Lead to conduct a build review and improve heat shield manufacturing for Dragon Crew structure.
• Identified root cause and corrective action for widespread defects in hardpoints used on the structure.
• Led multiple containments in lamination due to lack of adequate process controls and escapes from SpaceX suppliers. Saved multiple million dollars in material costs and elimination of risk to product.
• Evaluated core defects and material out-time risks that involved widespread material and part containments. Successfully implemented controls that addressed root cause and prevented re-occurrence.
• Expert in evaluation of incoming carbon fiber prepreg composite defects and defects induced in processing.
• Designed and implemented test program to understand the impact of various flexcore defects on shear properties and design impact.
• Advanced new approach for FOD classification in lamination cleanroom to separate nuisance micro FOD from FOD that is a risk to product.
• Co-author of composite inspection manual with significant revisions used by quality inspectors. Team lead for lamination cure improvements overhaul. Successfully revamped the process for how composite structures are specified, monitored and controlled for quality assessments resulting in significant drop in production issues.
• Led investigation into severe wrinkles during automated fiber placement of charge used on 2nd stage fairing which had led to large structural strength degradation and led to scrapping multiple parts. With the improvements implemented, the problem was eliminated.
• Proposed new method for manual layup process for complex parts to be mapped down to the specific hand movements in the work order instructions. Method led to improved quality of hand layup parts with complex geometries.

Boeing, Everett, Washington, Structural Analyst - Certification Team, 2006 - 2009

• Lead engineer for the 787 Fuselage Effects of Defects program at The Boeing Company.
• Managed an extensive program to study the effects of the manufacturing defects and anomalies encountered during the production ramp-up of the composite one-piece barrel. Since the as-built structure can often deviate from the original design and process specifications, the effort was critical in assessment and validation of production barrels and thus enabled the certification of the structure by civil aviation regulatory agencies.
• Developed the, Structural Analysis Guidance document for assessing margin impacts due to manufacturing defects on composite primary structure, at The Boeing Company for the 787 fuselage structure.
• The work contained detailed descriptions of procedures for adjusting structural margins when defects or anomalies are concerned. Detailed procedures have found use in pre-production verification, process control document development, and Material Review Board activity.
• The company and suppliers have used procedure continuously, make decisions regarding scrap, repair or leave as-is decisions during production of the one-piece composite barrels. Still used in Boeing on 787 MRB.
• Structural Analyst for 787 aluminum floor stanchion nonlinear buckling analysis for optimized sections using large cutouts for weight reduction.
• Analyst for 787 cargo floors barrier net due to unrestrained cargo in 9G FWD crash Condition.

Undisclosed University, Professor, 2009 - Present

• Researcher in composite materials and structures - defects and NDE. Author of numerous articles and books in this area.
• Author of a new book on effects-defects in composites. A five-year project making, addresses the surprisingly limited information available to the engineering practitioners to understand how to handle the more than fifty composites related defects and manufacturing anomalies.
• The book's methodology is to go beyond classification and bridge the gap between processing, non-destructive testing and structural design.
• Led a project for One Aviation's Kestrel 350 to investigate the low-velocity impact resistance of certain closed cell polymeric foam core sandwich structure with woven carbon-fiber and epoxy laminate facesheets.
• The low-cost alternative materials were investigated using numerical and experimental methods for multiplier degradations when impacts causing barely visible damage occur at temperature extremes.
• This effort resulted in design changes to increase the resilience of the composite airframe structure to meet required damage tolerance capabilities.
• Developed a new system in collaboration with Middleton Spectral Vision (Madison, WI) that scans a structure for resin pockets and associated wrinkles and provides rapid structural reliability information of the composite article.
• Developed software that perturbs the mesh in a numerical finite element model in proportion to the detected defect map using a hyperspectral near infrared imaging measurement tool.
• The results published in the Composites Science and Technology journal are shown to detect the effects of resin pockets identifying regions of lower flexural strength from 45-90% of the pristine conditions.
• Invented a new composite-based electrical current sensor device. The device includes a novel strain distribution converter made using a magnetostrictive polymer composite material and incorporates an optical fiber.
• Developed new magnetostrictive composite with unique capability for wireless detection of magnetic fields caused by electrical current. Patent for this invention was approved and granted by the United States Patent and Trademark Office.

Honors & Publications

Credentials

Technology and Tools

• Matlab
• Minitab
• Abaqus
• LabVIEW
• MathCAD
• Fortran
• 3D Digital Image Correlation - ISTRA
• Mistras Acoustic Emission
• Ultrasonic testing
• Advanced Materials Characterization
• Dynamic Mechanical Analysis, DMA
• Thermal Gravimetric Analysis, TGA
• Optical and Laser Confocal Microscopy
• Scanning Electron Microscopy
• Particle sizer
• Spectroscopy, FTIR
• Differential Scanning Calorimetry, DSC

License

• Registered Professional Engineer, Washington

Academic and Professional Affiliations

Appointments

• Composites Build Reliability Group-Space Exploration Technologies Corp., SpaceX
• Materials Science and Engineering/ Civil Departments-University of Wisconsin, Milwaukee, Wisconsin
• 787 Dreamliner Fuselage Methods, Repairs and Major Tests,-Boeing Commercial Airplanes, Everett, Washington (Structural Analyst)
• D1D Development Fab-Intel Corporation, Hillsboro, Oregon (Senior Process Engineer)

Awards

• Fulbright Scholar, U.S. State Department
• Tau Beta Pi Engineering Honor Society, Elected Member

Publications

• Author-Co-Author of numerous peer reviewed articles, whitepapers, and educational text with over 60 publications and 5 books.

Education

• Ph.D. Composites Focus, Engineering, Georgia Institute of Technology, Atlanta GA
• M.S. Civil Engineering, University of Texas at Austin, Austin, TX
• B.S. Civil Engineering, University of Nebraska, Lincoln, NE