A New Multiple Proof Loads Approach For Estimating Correlations

  • Richard Johnson
  • Wenqing Lu
Part of the Statistics for Industry and Technology book series (SIT)


By employing reliability based design to structures, engineers can make efficient use of building materials. One important input to the design is the correlation between two or more strength properties such as bending and tensile strength. However, with wood products, there is the added complication that it is difficult to create good pairs of specimens. When specimens are tested to failure in one strength mode the specimen is destroyed. Somehow, information on both strength properties must be obtained from a single specimen. Our approach is to load each specimen to a specified load in strength mode one and then load survivors to failure in strength mode 2.

We first review our earlier experimental designs which do allow for the estimation of correlation in a bivariate normal distribution. Then, we present some results for a new design that uses multiple proof loading. Some preliminary results are also presented for estimating correlation under a bivariate Weibull distribution.

Keywords and phrases

Destructive testing estimation of correlation 


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Copyright information

© Springer Science+Business Media New York 2000

Authors and Affiliations

  • Richard Johnson
    • 1
  • Wenqing Lu
    • 1
  1. 1.University of WisconsinMadisonUSA

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