Test method of bending for plastics welded test specimen
1 Scope
This standard specifies the terms and definitions, symbols and descriptions, test principles, test devices, test sample preparation, state adjustment, test methods, test results and test reports by the test method of bending for plastics welded specimen.
This standard is applicable to bending testing for thermoplastic samples in hot air welding, extrusion welding, hot fusion welding, electric fusion welding and other welding procedures.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 2918-1998 Plastics — Standard atmospheres for conditioning and testing
GB/T 3375 Welding terminology
GB/T 11997 Plastics — Multipurpose test specimens
GB/T 17200 Technical specification for tensile, compression and flexural testing machines for rubber and plastics (constant rate of traverse)
HG/T 4282 Test method of tensile for plastics welded test specimen
JB 4708 Welding procedure qualification for steel pressure vessels
ISO 2602:1980 Statistical interpretation of test results — estimation of the mean — confidence interval
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 3375, HG/T 4282, JB 4708 and the following apply.
3.1
bending angle
angle change of test sample after extrusion and bending
3.2
ram displacement
displacement of the contact point between the head and the test sample after extrusion and bending
4 Symbols and interpretations
Symbols used in this standard Table 1 and its interpretations are given in Table 1, and its specific meanings are expressed in Figures 1 to 9, Equations (1) to (3), Table 2 and Table 4.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and interpretations
5 Test principle
6 Test device
6.1 Testing machine
6.2 Support and indenter
6.3 Measuring appliance
7 Test sample preparation
7.1 Sampling requirements
7.2 Shape and dimension of test sample
7.3 Test sample preparation method
7.4 Number of test samples
8 Conditioning
9 Test methods
9.1 Test environment
9.2 Sample installation
9.3 Ram speed
9.4 Records
9.5 Bending mode
10 Judgment of test results
10.1 General
10.2 Determination of bending angle
10.3 Determination of ram displacement
10.4 Ram displacement at 160° bending angle
11 Test report
Annex A (Informative) Format of test report
Figure 1 Schematic diagram for bending test
Figure 2 Test sample shape of parallel surface (plate and pipe)
Figure 3 Test sample shape of radiant surface (pipe)
Figure 4 Stereo schematic diagram of pipe welding bending sample sampling
Figure 5 Parallel surface sampling and stress direction
Figure 6 Sampling and stress direction of radiant surface
Figure 7 Various bending types of welding samples
Figure 8 Schematic diagram of original bending angle and ram displacement of test sample
Figure 9 Schematic diagram of final bending angle and final ram displacement of test sample
Table 1 Symbols and interpretations
Table 2 Test sample dimension and relevant dimensions of test device
Table 3 Bending ram speed
Table 4 Ram displacement values when the bending angle is 160°
Table A.1 Bending test report of plastic welded test sample
