Alfred M. Pettinger, Ph.D., P.E.

Dr. Pettinger's areas of expertise include mechanical behavior of materials, structural engineering, product design, reliability, durability, and maintainability. Dr. Pettinger’s research and investigative work has primarily involved fatigue, fracture, overload, environmental effects, operation, controllability, and maintenance practices. He has conducted design and damage tolerance evaluations on pipelines, metal and composite aircraft, and equipment. His work on pipelines and pipe systems ranges from soil-pipe interactions to pipe vibration, including the evaluation of mechanical couplings and welded joints. He has investigated the integrity and performance of pipelines and piping systems for buildings and nuclear power plants. His aerospace work focuses on structural engineering, damage tolerance and failure analysis. In addition, Dr. Pettinger has analyzed vehicle components and industrial machinery such as pumps, actuators, gears, and turbines. He has investigated numerous accidents involving manufacturing equipment and their operation.

Prior to joining Exponent, Dr. Pettinger held Instructor, Teaching Assistant, and Research Assistant positions at the Massachusetts Institute of Technology (MIT) in the field of mechanics of materials and applied mechanics, where he conducted research and taught classes in mechanics. In addition, he worked in Germany for the European aerospace industry on the design and analysis of various components, with a specialization on glass and carbon fiber reinforced composite components (GFRP, CFRP). He has also been trained as a craftsman.

Pettinger A, Montgomery R. Hazards and benefits of pipelines crossing the South American Andes. Pipeline & Gas J, August 2009; 236(8).

Pettinger A, Rakow J. Failure analysis of composites: Sandwich structures. Advanced Materials & Process, August 2009; 167(8).

Pettinger A, Rakow J. Failure analysis of composites: Laminate behavior. Advanced Materials & Process, July 2009; 167(7).

Pettinger A, Cameron K. Assessing pipeline integrity using fracture mechanics and currently available inspection tools. The 2008 European Conference on Evaluation and Rehabilitation of Pipelines, Prague, Czech Republic, October 2008.

Pettinger A, Rakow J. Failure analysis of composite structures in aircraft accidents. Annual Conference of the International Society of Air Safety Investigators, Cancun, Mexico, September 2006.

Pettinger A, Moore D. Supplemental type certificates: Understanding and assessment. Journal of Air Law and Commerce, 40th Annual SMU Air Law Symposium, February 2006.

Pettinger A, Abeyaratne R. On the nucleation and propagation of thermoelastic phase transformations in anti-plane shear. Part 1 couple-stress theory. Computational Mechanics 2000; 26, Springer Verlag.

Pettinger A, Abeyaratne R. On the nucleation and propagation of thermoelastic phase transformations in anti-plane shear. Part 2 problems. Computational Mechanics 2000; 26, Springer Verlag.

Pettinger A. A regularized couple stress theory and its implications on nucleation and kinetics of phase transformations in anti-plane shear. Ph.D. dissertation, Massachusetts Institute of Technology, May 1998.

Pettinger A. Optimal focusing of the heat flux by an anisotropic medium. M.S. thesis, Worcester Polytechnic Institute, July 1993.

Pettinger A. Überarbeitung und Optimierung der Seastar Höhenleitwerksflosse: Vergleich einer GFK-und CFK Stuktur (Design and optimization of the seastar’s horizontal stabilizer: A comparision between GFRP and CFRP). Diplomarbeit, Fachhochschule München, July 1991.

Selected Reports

Pettinger A, Arruda J. Tractor gear box evaluation on the matter of Armando Orozco Juarez v. Pacific Vineyard Company. Failure Analysis Associates, Inc. Report, submitted to the State Compensation Insurance Fund of the State of California, May 2009.

Pettinger A, Moore C.D. Engineering analysis of Pemco B737-300 Quick Change Modification. Exponent, Failure Analysis Associates, Inc., Rule 26B Report, May 2005.

Pettinger A. Stress analysis of the Sunrise Mountain Landfill Pipeline. Exponent, Failure Analysis Associates, Inc. Report, submitted to the EPA, December 2003.

Pettinger A, Hamilton D, Lyle J. Expanded pipeline investigation report, Sunrise Mountain Landfill Clark County, Nevada. Exponent, Failure Analysis Associates, Inc. Report, submitted to the EPA, August 2003.

Pettinger A. Rollover accident of a tractor-tank semi trailer. Exponent Failure Analysis Associates, Inc. report, March 2003.

Pettinger A. 06CW4 - Failed item analysis report, Contractor AST, Prepared for Project Manager Soldier System (U.S. Army). Exponent Failure Analysis Associates, Inc., Report, March 2003

Pettinger A. 06CW5 - Failed item analysis report for DT, prepared for Project Manager Soldier System (U.S. Army). Exponent Failure Analysis Associates, Inc. report, March 2003.

Pettinger A. 06CW - Failed item analysis report, Final Contractor HALT Test, prepared for Project Manager Soldier System (U.S. Army). Exponent Failure Analysis Associates, Inc. report, February 2003.

Pettinger A. 06CW1 - Failed item analysis report, prepared for Project Manager Soldier System (U.S. Army). Exponent Failure Analysis Associates, Inc. report, February 2003.

Pettinger A. 06CW3 - Failed item analysis report for E0E (EFA), prepared for Project Manager Soldier System (U.S. Army). Exponent Failure Analysis Associates, Inc. report, February 2003.

Pettinger A, Fessler J, Shekerlian S, Medhekar S. Recommendations for the design, manufacture, installation, operation and maintenance of the cement-lined pipe for Well IID-16. Exponent, Failure Analysis Associates, Inc. report, June 2002.

Pettinger A. Follow-up survey of Invensys MA-200 Series Actuators, for submittal to the U.S. Consumer Product Safety Commission. Exponent Failure Analysis Associates, Inc. report, April 2002.

Pettinger A, Klopp R, Duffner D. Gear analysis of Invensys MA-220 and MA-230 Actuators, for submittal to the U.S. Consumer Product Safety Commission. Exponent Failure Analysis Associates, Inc. report, February 2002.

Pettinger A, Du Y. Failure investigation of Challenger bus lifts, Valley Transportation Authority, CA. Exponent Failure Analysis Associates, Inc., Report, September 2000.

Pettinger A, Medhekar S, Pye J. SSD design risk assessment. Prepared for Space Systems LORAL, Exponent Failure Analysis Associates, Inc., Report, June 2000.

Pettinger A, Wu M, Jewett C, Emery J, Foulds J, Kalinowski A, James B. Finite element analysis and fatigue life evaluation of TALENT Endoluminal NiTi Spring Stent Graft System. Exponent Failure Analysis Associates, Inc. report, April 2000.

Book Chapters

Pettinger A, Rakow J. Chapter 9. Structures Investigation: Composite Materials. Manual of Aircraft Accident and Incident Investigation, Part III. International Civil Aviation Organization, Doc 9756-AN/965.

Technical Reports

Pettinger A, Rakow J. Failure analysis of composites: A manual for aircraft accident investigators. First Edition, International Society of Air Safety Investigators, 2007.

Invited Speaking Engagements

Pettinger A. Updated pipeline integrity analysis of the Camisea Transportation System. Presented at 6th public conference on the Camisea Project by the Inter-American Development Bank, Lima, Peru, November 2007.

Pettinger A. Pipeline integrity analysis of the Camisea Transportation System. Presented at 5th public conference on the Camisea Project by the Inter-American Development Bank, Washington D.C., June 2007.

Pettinger A. Safety investigation elements: Design, materials, usage and manufacture. Presented at Center for Occupational and Environmental Health of the University of California, Irvine, October 2005.

Energy Power and Pipelines

Performed a failure analysis investigation of a ruptured heavy crude oil pipeline in Ecuador. The investigation included a metallurgical field investigation, site inspection, geotechnical evaluation and review of the operational data to determine the root cause of this pipeline failure.

Evaluated the inspection and testing requirements of a large gas pipeline in Australia. The investigation included the review of prior evaluations by the operator, various consulting firms and Universities. Dr. Pettinger provided an independent assessment for the operator’s In-line inspection (ILI) needs.

Assisted the Inter-American Development Bank (IDB) with a pipeline integrity study of the Camisea transportation system in Peru, after the pipeline experienced 5 spill incidents in 19 months of operation. The IDB retained us to perform a failure analysis, conduct a design audit and risk assessment, and to provide the operator with recommendations to reduce future operational risks in the areas of seismicity, river scour, geotechnical stability, and mechanical pipe integrity. The design audit included a review of the applicable regulations, and standards promulgated by the American Society of Mechanical Engineers (ASME) and the American Petroleum Institute (API). In addition, we reviewed the adequacy of the pipe material, girth welds, and the subsequently performed hydrostatic testing. The failure analysis investigation integrated geotechnical site investigations, metallurgical investigations, in-line inspection (ILI) data, and external pipe inspection data with a detailed fracture mechanics analysis of the girth welds, to determine the root cause of the spill incidents.

Assisted the general contractor of a nuclear power plant where a large pipe of the primary circuit was vibrating excessively, significantly reducing the allowable power production. The assignment included the technical support of the general contractor’s engineering staff on fluid induced pipe vibration, and the selection of the most effective mitigation methods to reinstate full power production.

Performed a feasibility and due diligence study for a pipeline expansion project in Africa.

Assisted the operator of a nuclear power plant in the identification of pump and pipe related vibration problems. Identified the root cause and proposed structural changes to mitigate the vibration problem.

Assisted a power plant operator in the evaluation of a vibration related problem of a large induced fan. Evaluated the proposed design changes and assisted the general contractor in identifying the problem and develop an effective solution.

Reviewed the design of high temperature sour gas flow lines to address issues of upheaval buckling and pipe integrity.

Performed failure analysis and design evaluations of various gas distribution systems made of polyethylene and steel pipe. The investigation included the analysis of pipe soil interactions, failure analysis of various pipe components and a performance evaluation of compression couplings.

Evaluated the creep behavior and risks associated with carbon steel welds for high temperature steel pressure vessel.

Performed a failure analysis and designed a replacement for a cement lined pipeline system at a geothermal power plant. This project included a root cause analysis, a preliminary pipe stress analysis, the development of design criteria, qualified welding procedures, construction specifications, and a start up procedure.

Performed design studies on a pipeline system that was intended to cross a landfill. This effort included the design of a large diameter above ground HDPE pipeline system.

Evaluated various drainage and sewer piping systems for various parties where soil movement was identified to a significant risk factor.

Performed a root cause failure analysis investigation of a large diameter low pressure air piping system. The investigation determined that the failure of the expansion joints during pressure testing was related to the design of the piping system.

Conducted a performance evaluation and root cause analysis of a thermal energy storage system, including its piping, tanks, chillers, energy storage medium, and auxiliary equipment.

Machinery Design, Safety, and Maintenance

Reviewed and evaluated the design of a proprietary machine design to manufacture highly engineered plastic films.

Performed a fitness of service evaluation of the mechanical equipment used in the Biosphere 2.

Performed several root cause analysis on the failure of various structural components of trailers, semi-trailers, buses, and recreational trailers. Manufacturing defects, welding quality, weld design, as well as design defects, were evaluated in this context.

Responsible for Exponent’s failed item analysis and HALT/HASS of the USA Army’s Land Warrior system (fully integrated wearable communication and situational awareness system for the soldier). This project included the system’s evaluation of all components, development of test procedures, and execution of the system HALT.

Performed a design review and root cause analysis of a large floating dredge, which included a review of the structural design of the pontoons. Specifically, issues related to stringer and frame placement, material wall thickness, and structural welding were evaluated.

Performed design reviews and root cause analysis of various gearboxes, gas turbines, and bearings. Overall, Dr. Pettinger has performed close to one hundred design evaluations and accident investigations on machinery in the food processing industry, manufacturing industry, agriculture field, heavy engineering industry, and the consumer goods area.

Airplane Design and Maintenance

Performed a review of the supplemental type certificate of a converted Boeing 737-300 for the operator. This investigation included a structural review and damage tolerance evaluation of an added upper deck main cargo door and its surround structure, with respect to compliance with the applicable Federal Aviation Regulations.

Performed a design review and accident investigation of the composite fiber reinforced plastic vertical tail of an Airbus 300-600.

Reviewed structural aspects of the supplemental type certificate of a modified Boeing 747 to evaluate the structural integrity and compliance with applicable Federal Aviation Regulations. This investigation included the structural analysis of the rear fuselage section with an added upper deck cargo door.

Executed the design and analysis of two horizontal stabilizers for the Dornier Composites Seastar, which was developed in the late 80s. This assignment included the design of two horizontal stabilizers to reduce the weight of the existing design and to evaluate different design and manufacturing techniques. One design study utilized carbon fiber reinforced plastics and the other glass fiber reinforced plastics. Integral as well as sandwich designs were evaluated in the course of this design study. In addition, analysis tools were developed and a complete set of manufacturing drawings of two designs were provided.

• Member of the Power Train and Gear Committee of ASME
• Vice-Chair of the Special Committee on Engineering Licensure, ASME
• American Society of Mechanical Engineers (member)
• ASM International (member)
• SAE International (member)
• ASME International Design Engineering Technical Conference/ IDETC/CIE 2009 – Technical Papers Review Coordinator, Paper Reviewer, Session Chair
• ASME International Design Engineering Technical Conferences, Paper Reviewer, Long Beach, CA, 2005