MSE2094
Analytic Methods in Material Science

Assignment #6: Statistial Analysis of Fracture Data

Ronald D. Kriz
College of Engineering
Virginia Tech

DUE: Tuesday April 7, 1998

Objective: Learn how to statistically analyze data and write a Fortran program that you can use in future projects.

Summary: Research related to fracture tests.

Given: Strength populations of graphite/epoxy laminates

Geometry:

" [08] " = Unidirectional lamina

" Type I" = Stacking sequence [0, +45, -45, 90] symetric

" Type II" = Stacking sequence [0, 90, +45, -45] symetric

Environmental Conditioning

" Wet " = Saturated with diffused water

" Dry " = Dehydrated of all absorbed water

Down load data files.

Calculate: Population mean and standard deviation for all six populations. Compare strength populations where only one variable is changed (i.e. Wet vs. Dry) and use the student T test to compare populations and conclude if this parametric change is statistically significant.

Write your solution in C or Fortran and make the following comparisions.

1. Type I: Wet vs. Dry

2. Type II: Wet vs. Dry

3. Dry: Type I vs. Type II

4. Wet: Type II vs. Type I

5. [08]: Wet vs. Dry

6. Wet: [08]: Randon fracture morphology vs. Single dominate crack morphology*

7. Test if the four different samples (Single-Dominant, Grip, Staggered, Broomed) are indeed from the same population of Wet: [08] fractures.