Research Papers: Design Theory and Methodology

Q2S2: A New Methodology for Merging Quantitative and Qualitative Information in Experimental Design

[+] Author and Article Information
Rahul Rai

Automated Design Lab, Department of Mechanical Engineering, University of Texas at Austin, Austin, TX 78712-0292rahulrai@mail.utexas.edu

Matthew Campbell1

Automated Design Lab, Department of Mechanical Engineering, University of Texas at Austin, Austin, TX 78712-0292mc1@mail.utexas.edu


Corresponding author.

J. Mech. Des 130(3), 031103 (Feb 05, 2008) (12 pages) doi:10.1115/1.2829884 History: Received May 30, 2006; Revised October 10, 2007; Published February 05, 2008

Sequential sampling refers to a set of experimental design methods where the next sample point is determined by information from previous experiments. This paper introduces a new sequential sampling method where optimization and user knowledge are used to guide the efficient choice of sample points. This method combines information from multiple sources of varying fidelity including actual physical experiments, computer simulation models of the product, and first principles involved in design and designer’s qualitative intuition about the design. Both quantitative and qualitative information from different sources are merged together to arrive at a new sampling strategy. This is accomplished by introducing the concept of a confidence function C, which is represented as a field that is a function of the decision variables x and the performance parameter f. The advantages of the approach are demonstrated using different example cases. The examples include design of a bistable microelectro mechanical system switch, a complex and relevant mechanical system.

Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Figure 1

A single experiment in the design of a heat sink shows that an experiment run at l=4in. yields a surface temperature of 600F

Grahic Jump Location
Figure 2

(a) The C field created by introducing the results of a single experiment and (b) the C field that results from including monotonicity information

Grahic Jump Location
Figure 3

The Q2S2 process is a cycle of six main steps

Grahic Jump Location
Figure 4

In Example 2, taken from Martin and Simpson (37)

Grahic Jump Location
Figure 5

In Example 2, the Q2S2 process slowly approximates the true oxidant-temperature relationship. (a) After five nearly evenly distributed sample points. (b) The C′ plot at this stage shows several local optima to sample next. (c) The relationship after ten points; many of which are between the ascribed monotonic regions.

Grahic Jump Location
Figure 6

Actual model for the projectile problem

Grahic Jump Location
Figure 7

The metamodel curve fit for the projectile problem: (a) using FF, (b) using Latin hypercube, (c) using generalized linear models, (d) using QS, and (e) using Q2S2

Grahic Jump Location
Figure 8

Comparison of sampling methods

Grahic Jump Location
Figure 9

(a) Potential energy as a function of changing configuration of a MSE system (b) Force versus displacement curve of a MSE system

Grahic Jump Location
Figure 10

Step-by-step decoding of the representation of the structure. (a) First beam of length l1 is attached at the origin at orientation angle θ1. (b) Second beam of length l2 and orientation angle θ2 is added to the end of the first beam. (c) The symmetrical half of the structure after adding all the beams and anchoring the beam ends. (d) The final structure. Also, note that the origin is considered as the loading point.

Grahic Jump Location
Figure 11

SLS manufactured “macro” prototypes

Grahic Jump Location
Figure 12

Feasible solutions generated in ANSYS



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In