GB/T 15248-2008The test method for axial loading constant-amplitude low-cycle fatigue of metallic materials (English PDF)

1 Scope

This standard specifies the equipment, samples, test procedures, test results and test processing of metallic materials amplitude axial low cycle fatigue test

Reports.

This standard applies to metallic materials, and the funnel-shaped cross-section specimens subjected to axial stress amplitude or low-cycle fatigue test strain is not included

Test full-size components, structural parts. Inelastic strain and time applies to the time-dependent inelastic strain unrelated to or smaller than

Considerable temperature and strain rate. Allows testing at ambient factors such as temperature, pressure, humidity, media, etc., but these factors throughout the experiment

Process should be kept constant.

NOTE. When this guide can be analyzed as a standard material development, mechanical design, process and quality control, performance measurement and failure low cycle fatigue test.

2 Normative references

The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent

Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research

Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.

GB/T 10623 mechanical properties of metal test terminology

GB/T 12160 uniaxial extensometer calibration test

JJG556 axial loading fatigue testing machine test procedures

3 Symbol

Symbols used in this standard, name, unit and are described in Table 1.

Table 1 symbol, name, unit and description

Symbol Name Unit Description

deltaepsilont total strain range mm/mm in one cycle, the algebraic difference between the maximum and minimum strain, namely. deltaepsilont = epsilonmax-epsilonmin

Half deltaepsilon/2 strain amplitude mm/mm strain range

epsilonmax maximum strain mm/mm in one cycle, the maximum strain algebraic value. Stretching is positive, negative compression

The minimum value for generations epsilonmin minimum strain mm/mm in one cycle, the strain

Elastic strain range deltaepsilone mm/mm equal stress divided by elastic modulus range, namely. deltaepsilone = deltasigma/E

deltaepsilonp plastic strain range mm/mm taking the difference between the total strain range elastic strain range, namely. deltaepsilonp = deltaepsilont-deltaepsilone

deltasigma stress range MPa cycle in one cycle, the algebraic difference between the maximum stress and minimum stress, namely. deltasigma = sigmamax-sigmamin

Half deltasigma/2 MPa stress amplitude stress range

sigmamax maximum stress MPa in one cycle, the maximum value on behalf of the stress

sigmamin minimum stress MPa in one cycle, the smallest algebraic value of stress

Rsigma stress ratio - Rsigma = sigmamin/sigmamax

Repsilon strain ratio - Repsilon = epsilonmin/epsilonmax

Nf cycles to failure for several weeks to reach the number of cycles to failure

Reverse Number Reverse 2Nf failure to reach the number of failure reverse frequency […]