Vehicle technology experts win best paper award for tome on condition-based maintenance

June 13, 2012

Story Highlights

  • VTD scientists coauthored best paper for Structures and Materials Sessions during the American Helicopter Society 68th Annual Forum and Technology Display recently.
  • The paper described the state-of-the-art probabilistic methodology for risk based fatigue life management in support of Army CBM+ for structural integrity.
  • The paper will be submitted for the consideration of the Alfred Gessow Forum Best Paper Award.

"Dr. Chi-Yu "Michael" Shiao, Dr. Tzi-Kang Chen, and Dy Le, from the Mechanics Division of the Vehicle Technology Directorate, coauthored the best paper for the Structures and Materials Sessions during the American Helicopter Society 68th Annual Forum and Technology Display, May 1-3, at the Fort Worth Convention Center in Texas.

This forum, which focused this year on "Steering Vertical Flight Technology in New Directions," is an international conference on vertical flight technology.

Their paper, "Probabilistic Damage Tolerance Analysis of Debonded Sandwich Composites," described the state-of-the-art probabilistic methodology for risk based fatigue life management in support of Army CBM+ for structural integrity.

"I definitely feel honored to be recognized by my peers in this technical area," said Shiao. "I am also encouraged by that my research result can provide proper means to improve the safety and reliability of Army vehicles that our Soldiers are operating to defend our country."

Shiao said damage tolerance and risk-based fatigue life management in support of Army CBM+ for structural integrity considers uncertainties like initial and repair qualities, material resistance and impact damage among other sources for the probabilistic risk assessment. Due to the complexity involved in the assessment, multi-disciplines are required to develop the probabilistic methodology including structural mechanics, fracture mechanics, structural reliability, probabilistic and statistical methods, uncertainty modeling and probabilistic damage propagation.

"Although these types of problems can normally be solved by Monte Carlo simulations (MCS), the computational efficiency using MCS to achieve a required accuracy is of great concern," he said. ARL developed a methodology to relieve the computational burden of traditional MCS methods for various maintenance strategies using NDI and SHM for damage monitoring. He said that methodology combines the generality of MCS with the efficiency of analytical probabilistic methods. The core of the method is a recursive probabilistic integration method, which is a way to systematically transform the random fatigue patterns using MCS to a more logical and manageable probabilistic event tree representation. Using the event tree, state-of-the-art efficient reliability methods such as importance sampling techniques can be applied, which results in a significant improvement on computational efficiency.

"ARL's role is to develop and demonstrate the state-of-the-art probabilistic methodology and provide predictive tool that can accurately and efficiently provide the evidence of need for maintenance action that is essential and critical to the success of Army CBM and CBM+ implementation. ARL will also transition to and assist stake holders to prepare necessary guidance," said Shiao.

The paper was selected from 20 others in the Structures and Materials Session. The technical committee representing the coauthors' areas of expertise will submit up to three papers, including theirs, this year for the consideration of Alfred Gessow Forum Best Paper Award.

The Alfred Gessow Forum Best Paper Award is presented to authors of submissions that stimulate wider interest in presenting papers at the AHS Forum, encourage quality presentations at the AHS Forum and that ensure that AHS forwards top works to the European Rotorcraft Forum.

Selection committee for Structures and Materials Session includes rotorcraft equipment technical experts from Boeing, Bell and Sikorsky, as well as experts from academia, the U.S. Navy and Army, and from the Australia Defense Department.

This year, the three-day event included 250 presentations on every technical discipline from Acoustics to Unmanned Systems.

The Technology Display that runs concurrent with the Forum showcases cutting edge vertical flight technologies around the world, and includes other technologies more broadly applicable to aerospace in general. Leading manufacturers, service providers, defense agencies, universities and research and development organizations showcased the latest developments in vertical flight technology and advancements in airframe, propulsion, avionics, systems integration and simulation technology.

 

Last Update / Reviewed: June 13, 2012