Description
| Abstract: | A new computerized technique has been developed to measure wavespeed and attenuation in thin specimens in the through-the-thickness direction. The wavespeed in monolithic material can be measured with a precision of 0.1%. In heterogeneous materials the wavespeed has been measured to a precision of 0.2% and attenuation to 2.0%. This technique was used for the non-destructive evaluation of matrix cracks in cross-ply graphite/epoxy laminates and it was found that the through-the thickness attenuation is a very sensitive measure of matrix cracks but the wavespeed is not. The plate wave or Lamb wave equations for a general composite laminate immersed in a fluid have been developed and an accurate numerical solution has been obtained. The in-plane measurements of wavespeed and attenuation were made by utilizing the Lamb waves. Both wavespeed and attenuation have been found to be sensitive measures of matrix cracks in cross-ply laminates. |
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| Item Description: | Typescript (photocopy).
Vita. |
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| Physical Description: | xv, 150 leaves : illustrations ; 29 cm |
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| Bibliography: | Includes bibliographical references (leaves 130-141). |
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