Elastic-Plastic deformation studies in 4140 steel using the critically refracted longitudinal (Lcr)wave technique /

2.25MHz and 5MHz. Although slightly different acoustoelastic

Bibliographic Details
Main Author: Tang, Wei, 1957-
Format: Thesis eBook
Language:English
Published: [Place of publication not identified] : [publisher not identified] ; 1996.
Subjects:
Online Access:Link to OAKTrust copy
Description
Summary:2.25MHz and 5MHz. Although slightly different acoustoelastic
approached. It is applicable even in a passed yield region.
below the elastic limit is on, it is also capable of
by only 2︢ ns, (0.026% of total travel time). When the load
can not only predict the applied stress level when a load
constants were obtained for both 2.25 MHz and 5 MHz
frequencies in the elastic region (up to 80% of the yield
in predicting the acoustoelastic constant. The I MHz
In the elastic-plastic region, a simple quadratic
indicating prior yielding, in terms of residual strain, when
interesting results. When an applied load was below the
material in the elastic-plastic region. Both applied tensile
of 4140 steel, typically used for turbine components, was
passed the yield point, the "return to no-load" LCR travel-
probe sets of three different nominal frequencies, IMHZ,
procedure was found not to be adequate for the plate type
relationship between the LCR travel time and the residual
residual strain. After load release, a 12.8% residual strain
resulted in a 15 ns (0.198% of total travel time) change in
specimen using a 5 MHz probe set provided some very
strain may replace the linear correlation between the LCR
strength), statistically both have no significant difference
stress and residual strain effects are discussed. A sample
stress-strain behavior until the yield stress level is
structure. Data obtained in post yield tests on the same
technique has been used to investigate a typical turbine disk
tested. The acoustoelastic phenomenon was evaluated using
the "no-load" travel time. The test results indicate that
the component has been worked in an elastic-plastic region.
The critically refracted longitudinal (LCR) wave ultrasonic
The LCR travel time, or the relative change on LCR velocity,
the LCR ultrasonic technique can linearly track the material
time showed a distinct change, due to the occurrence of
velocity and applied stress in the elastic limit.
yield point, the "return to no-load" LCR travel time varies
Item Description:"Major subject: Mechanical Engineering".
Vita.
Physical Description:xii, 94 leaves : illustrations ; 28 cm.
Also available online.
Issued also on microfiche from Lange Micrographics.
Bibliography:Includes bibliographical references: 71-73.