ASTM-D4093 › Historical Revision Information
Standard Test Method for Photoelastic Measurements of Birefringence and Residual Strains in Transparent or Translucent Plastic Materials
The following bibliographic material is provided to assist you with your purchasing decision:
Scope
1.1 This test method covers measurements of direction of principal strains,
1.2 In addition to the method using a compensator described in this test method, other methods are in use, such as the goniometric method (using rotation of the analyzer) mostly applied for measuring small retardation, and expressing it as a fraction of a wavelength. Nonvisual methods employing spectrophotometric measurements and eliminating the human judgment factor are also possible.
1.3 Test data obtained by this test method is relevant and appropriate for use in engineering design.
1.4 The values stated in either SI units or inch-pound units are to be regarded as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Note 1There is no known ISO equivalent to this test method.
Significance and Use
The observation and measurement of strains in transparent or translucent materials is extensively used in various modeling techniques of experimental stress analysis.
Internal strains induced in manufacturing processes such as casting, molding, welding, extrusion, and polymer stretching can be assessed and part exhibiting excessive strains identified. Such measurements can lead to elimination of defective parts, process improvement, control of annealing operation, etc.
When testing for physical properties, polariscopic examination of specimens is required, to eliminate those specimens exhibiting abnormal internal strain level (or defects). For example: Test Methods D 638
The birefringence of oriented polymers can be related to orientation, shrinkage, etc. The measurements of birefringence aid in characterization of these polymers.
For many materials, there may be a specification that requires the use of this test method, but with some procedural modifications that take precedence when adhering to the specification. Therefore, it is advisable to refer to that material specification before using this test method. Table 1 of Classification System D 4000
Keywords
birefringence; photoelastic measurements; photoelastic retardation; strain; strain optical constant; transparent plastics; ICS Number Code 83.080.01 (Plastics in general)
To find similar documents by ASTM Volume:
08.02 (Plastics (II): D3222 - D5083)
To find similar documents by classification:
71.080.99 (Other organic chemicals)
83.080.01 (Plastics in general)
This document comes with our free Notification Service, good for the life of the document.
This document is available in either Paper or PDF format.
Document Number
ASTM-D4093-95(2005)e1
Revision Level
1995 R05(E1) EDITION
Status
Superseded
Modification Type
Reapproval with Ed Change
Publication Date
July 1, 2005
Document Type
Test Method
Page Count
11 pages
Committee Number
D20.10