Norma de aluminio

Designation: E 399 – 90 (Reapproved 1997)

Standard Test Method for

Plane-Strain Fracture Toughness of Metallic Materials1
This standard is issued under the fixed designation E 399; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense.

1. Scope 1.1 This test method covers the determination of the planestrain fracture toughness (KIc) of metallic materials by tests using a variety of fatigue-cracked specimens having a thickness of 0.063 in. (1.6 mm) orgreater.2 The details of the various specimen and test configurations are shown in Annex A1-Annex A7 and Annex A9.
NOTE 1—Plane-strain fracture toughness tests of thinner materials that are sufficiently brittle (see 7.1) can be made with other types of specimens (1).3 There is no standard test method for testing such thin materials.

General information and requirements common to all specimen typesare listed as follows:
Sections Referenced Documents Terminology Stress-Intensity Factor Plane-Strain Fracture Toughness Summary of Test Method Significance and Use Precautions Practical Applications Apparatus Loading Fixtures Displacement Gage Design Displacement Measurements Specimen Size, Configurations, and Preparation Specimen Size Estimates Standard and Alternative Specimen Configurations Formsof Fatigue Crack Starter Notch Fatigue Cracking Crack Extension Beyond Starter Measurements before Testing Thickness Width Starter Notch Root Radius Specimen Testing Loading Rate Test Record Measurements after Testing Crack Length Crack Plane Angle Calculation and Interpretation of Results Analysis of Test Record Validity Requirements on Pmax/PQ Validity Requirements on Specimen Size Crack PlaneOrientation Designations Fracture Appearance Descriptions Reporting Precision and Bias Special Requirements for Rapid Load KIc(t) Tests 2 3 3.1.1 3.1.2 4 5 5.1.1-5.1.3 5.2 6 6.2 Annex A1 6.3 7 7.1 7.2 7.3.1 Annex A2 7.3.2.2 8.2.1 8.2.3 7.3.1 8.3 8.4 8.2.2 8.2.4 9 9.1 9.1.2 9.1.3 9.2 9.3 10 11 Annex A7

1.2 This test method also covers the determination of the specimen strength ratio Rsx where xrefers to the specific specimen configuration being tested. This strength ratio is a function of the maximum load the specimen can sustain, its initial dimensions and the yield strength of the material. 1.3 Measured values of plane-strain fracture toughness stated in inch-pound units are to be regarded as standard. 1.4 This test method is divided into two main parts. The first part gives generalinformation concerning the recommendations and requirements for KIc testing. The second part is composed of annexes that give the displacement gage design, fatigue cracking procedures, and special requirements for the various specimen configurations covered by this method. In addition, an annex is provided for the specific procedures to be followed in rapid-load plane-strain fracture toughness tests.
1This test method is under the jurisdiction of ASTM Committee E-8 on Fatigue and Fracture and is the direct responsibility of Subcommittee E08.07 on Linear–Elastic Fracture. Current edition approved Nov. 30, 1990. Published April 1991. Originally published as E 399 – 70 T. Last previous edition E 399 – 83. 2 For additional information relating to the fracture toughness testing of alumiinum alloys,see Method B 645. 3 The boldface numbers in parentheses refer to the list of references at the end of this test method.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

1

E 399 – 90 (1997)
1.5 Special requirements for the various specimen configurations appear in the following order:
Bend Specimen SE(B) Compact...