Structural Dynamics: Volume 2: Advanced Applications

Dr. Alvar M. Kabe is the Principal Director of the Structural Mechanics Subdivision of The Aerospace Corporation. His prior experience includes Director of the Structural Dynamics Department and Manager of the Flight Loads Section at The Aerospace Corporation. Dr. Kabe has made fundamental contributions to the state of the art of launch vehicle and spacecraft structural dynamics. He introduced the concept of multishaker correlated random excitation to better isolate modes for measurement in mode survey tests, and the concept of using the superposition of scaled frequency response functions to isolate modes for identification. He then introduced the concept of using structural connectivity information as additional constraints when optimally adjusting dynamic models to better match test data; this work has been cited over 260 times in other publications. Dr. Kabe developed the atmospheric flight turbulence/gust and time domain buffet loads analysis methodologies used on several operational launch vehicle programs, and he pioneered the concept of using structural dynamic models to compute atmospheric flight static-aeroelastic loads. Dr. Kabe led the development of a continually evolving integrated dynamics analysis system that has been used for over two decades to compute loads on over two dozen launch vehicle systems and their payloads. The work included independently developing and implementing analysis methodologies, developing loads and stress analysis models, computing loads, and establishing structural margins. This also included independent day-of-launch placard analyses and independent go/no-go launch recommendations. Dr. Kabe has led, co-chaired, or participated on numerous high level reviews and assessment teams that have had significant impact. He was a member of the Defense Science Board’s Aviation Safety Task Force, and he co-chaired four U.S. Air Force Titan IV Independent Readiness Reviews. He led the Space Shuttle Radar Topography Mission assessment, and he co-chaired NASA’s Mars Sample Return project review. In addition, Dr. Kabe is on the NASA Engineering Safety Center (NESC) Structural Dynamics Technical Discipline Team as a subject matter expert. Dr. Kabe has published 23 technical papers, and written over 150 corporate technical reports. He has taught undergraduate and graduate structural dynamics classes, presented invited seminars at major universities, and the Keynote at an AIAA Structural Dynamics Specialist Conference. Dr. Kabe has received numerous awards and over forty letters of commendation. The awards include the Trustees Distinguished Achievement Award, The Aerospace Corporation’s highest award, The Aerospace Corporation’s President’s Award, Division and Group Achievement Awards, and nine Program Recognition Awards. Dr. Kabe is a Registered Professional Engineer in the state of California; and his B.S., M.S., and Ph.D. degrees are from UCLA.

Dr. Brian H. Sako is a Distinguished Scientist in the Structural Mechanics Subdivision of The Aerospace Corporation. Prior to this position, Dr. Sako was an Engineering Specialist, a Senior Engineering Specialist, and an Aerospace Fellow. Dr. Sako has made significant contributions to the fields of structural dynamics, numerical analysis, and time series data analysis. His development of the filtering approach used to separate the more rapidly varying wind features from more slowly varying components is used on several launch vehicle programs to develop turbulence forcing functions for atmospheric flight loads analysis. Dr. Sako also developed an approach to remove tones from wind tunnel buffet test data; the approach was used, for example, on NASA’s Space Launch System (SLS) program. His developments have also made significant contributions to the assessment of the internal dynamic properties of rocket engines, pogo stability of launch vehicles, and the development of forcing functions for loads analysis. Dr. Sako developed state-of-the-art time series analysis and mode parameter identification tools that have been used to analyze data and identify structural dynamic parameters on numerous operational systems. The time series data analysis tool is used to assess flight and ground vibration test data. The mode parameter identification tool is used to extract mode parameters from launch vehicle and satellite mode survey test data, as well as flight data. Dr. Sako’s developments are used routinely to assess data from operational launch and space systems. Dr. Sako has published 25 technical papers, and written 100 corporate technical reports. He has taught graduate classes in numerical analysis, engineering mathematics, and signal processing. Dr. Sako has earned numerous awards and letters of commendation, including The Aerospace Corporation’s President’s Award, Division and Group Achievement Awards, and several Program Recognition Awards. Dr. Sako’s B.A. and M.A. degrees are from the University of Hawaii, and his Ph.D. is from UCLA.