NASA Scientific and Technical Aerospace Reports

20040121019 NASA Langley Research Center, Hampton, VA, USA
Taguchi Approach to Design Optimization for Quality and Cost: An Overview
Unal, Resit; Dean, Edwin B.; [1990]; 10 pp.; In English; 1991 Annual Conference of the International Society of Parametric
Analysts, 1 Jan. 1991, USA; No Copyright; Avail: CASI; A02, Hardcopy
Calibrations to existing cost of doing business in space indicate that to establish human presence on the Moon and Mars
with the Space Exploration Initiative (SEI) will require resources, felt by many, to be more than the national budget can afford.
In order for SEI to succeed, we must actually design and build space systems at lower cost this time, even with tremendous
increases in quality and performance requirements, such as extremely high reliability. This implies that both government and
industry must change the way they do business. Therefore, new philosophy and technology must be employed to design and
produce reliable, high quality space systems at low cost. In recognizing the need to reduce cost and improve quality and
productivity, Department of Defense (DoD) and National Aeronautics and Space Administration (NASA) have initiated Total
Quality Management (TQM). TQM is a revolutionary management strategy in quality assurance and cost reduction. TQM
requires complete management commitment, employee involvement, and use of statistical tools. The quality engineering
methods of Dr. Taguchi, employing design of experiments (DOE), is one of the most important statistical tools of TQM for
designing high quality systems at reduced cost. Taguchi methods provide an efficient and systematic way to optimize designs
for performance, quality, and cost. Taguchi methods have been used successfully in Japan and the USA in designing reliable,
high quality products at low cost in such areas as automobiles and consumer electronics. However, these methods are just
beginning to see application in the aerospace industry. The purpose of this paper is to present an overview of the Taguchi
methods for improving quality and reducing cost, describe the current state of applications and its role in identifying cost
sensitive design parameters.
Author
Taguchi Methods; Quality Control; Total Quality Management; Design Analysis
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STRUCTURAL MECHANICS
Includes structural element design, analysis and testing; dynamic responses of structures; weight analysis; fatigue and other structural
properties; and mechanical and thermal stresses in structures. For applications see 05 Aircraft Design, Testing and Performance; and
18 Spacecraft Design, Testing and Performance.
20040111124 Sandia National Labs., Albuquerque, NM, USA
Four-Parameter Iwan Model for Lap-Type Joints
Segalman, D. J.; Nov. 2002; In English
Report No.(s): DE2004-805877; SAND2002-3828; No Copyright; Avail: National Technical Information Service (NTIS)
The constitutive behavior of mechanical joints is largely responsible for the energy dissipation and vibration damping in
weapons systems. For reasons arising from the dramatically different length scales associated with those dis- sipative
mechanisms and the length scales characteristic of the overall structure, this physics cannot be captured through direct
numerical simulation(DNS) of the contact mechanics within a structural dynamics analysis. The difficulties of DNS manifest
themselves either in terms of Courant times that are orders of magnitude smaller than that necessary for structural dynamics
analysis or as intractable conditioning problems. The only practical method for accommodating the nonlinear nature of joint
mechanisms within structural dynamic analysis is through constitutive models employing degrees of freedom natural to the
scale of structural dynamics. In this way, development of constitutive models for joint response is a prerequisite for a
predictive structural dynamics capability. A four-parameter model, built on a framework developed by Iwan, is used to
reproduce the qualitative and quantitative properties of lap-type joints. In the development presented here, the parameters are
deduced by matching experimental values of energy dissipation in harmonic loading and values of the force necessary to
initiate macro-slip. (These experiments can be performed on real hardware or virtually via fine-resolution, nonlinear
quasi-static finite elements.) The resulting constitutive model can then be used to predict the force/displacement results from
arbitrary load histories.
NTIS
Energy Dissipation; Vibration Damping; Weapon Systems
20040111192 Building and Construction Research TNO, Delft, Netherlands
SUS: Survivability after Underwater Shock: Implementation of Whipping Bending Moment and Hull Plate Dishing
Bos, J.; March 2004; 25 pp.; In English
Contract(s)/Grant(s): A02/KM/109; TNO Proj. 006.38108
Report No.(s): TD-2004-0103; Rept-2004-CMC-R013; Copyright; Avail: Other Sources
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