BS EN 61788-6:2011
$167.15
Superconductivity – Mechanical properties measurement. Room temperature tensile test of Cu/Nb-Ti composite superconductors
| Published By | Publication Date | Number of Pages |
| BSI | 2011 | 36 |
IEC 61788-6:2011 covers a test method detailing the tensile test procedures to be carried out on Cu/Nb-Ti superconductive composite wires at room temperature. This test is used to measure modulus of elasticity, 0,2 % proof strength of the composite due to yielding of the copper component, and tensile strength. The value for percentage elongation after fracture and the second type of 0,2 % proof strength due to yielding of the Nb-Ti component serves only as a reference. The sample covered by this test procedure has a round or rectangular cross-section with an area of 0,15 mm 2 to 2 mm 2 and a copper to superconductor volume ratio of 1,0 to 8,0 and without the insulating coating. This third edition cancels and replaces the second edition published in 2008. It constitutes a technical revision which adds a new Annex C including specific examples of uncertainty estimation related to mechanical tests.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 6 | English CONTENTS |
| 8 | INTRODUCTION |
| 9 | 1 Scope 2 Normative references 3 Terms and definitions |
| 10 | 4 Principle 5 Apparatus 5.1 Conformity 5.2 Testing machine |
| 11 | 5.3 Extensometer 6 Specimen preparation 6.1 Straightening the specimen 6.2 Length of specimen 6.3 Removing insulation 6.4 Determination of cross-sectional area (So) 7 Testing conditions 7.1 Specimen gripping 7.2 Pre-loading and setting of extensometer 7.3 Testing speed |
| 12 | 7.4 Test |
| 14 | 8 Calculation of results 8.1 Tensile strength (Rm) 8.2 0,2 % proof strength (Rp0,2A and Rp0,2B) 8.3 Modulus of elasticity (Eo and Ea) 9 Uncertainty |
| 15 | 10 Test report 10.1 Specimen 10.2 Results 10.3 Test conditions |
| 16 | Annex A (informative) Additional information relating to Clauses 1 to 10 |
| 17 | Figure A.1 – An example of the light extensometer,where R1 and R3 indicate the corner radius |
| 18 | Figure A.2 – An example of the extensometer provided with balance weightand vertical specimen axis |
| 21 | Annex B (informative) Uncertainty considerations |
| 22 | Tables Table B.1 – Output signals from two nominally identical extensometers Table B.2 – Mean values of two output signals Table B.3 – Experimental standard deviations of two output signals |
| 23 | Table B.4 – Standard uncertainties of two output signals Table B.5 – Coefficient of Variations of two output signals |
| 25 | Annex C (informative) Specific examples related to mechanical tests Figure C.1 – Measured stress versus strain curve of the rectangularcross section NbTi wire and the initial part of the curve |
| 28 | Table C.1 – Load cell specifications according to manufacturer’s data sheet Table C.2 – Uncertainties of displacement measurement |
| 29 | Table C.3 – Uncertainties of wire width measurement Table C.4 – Uncertainties of wire thickness measurement Table C.5 – Uncertainties of gauge length measurement |
| 30 | Table C.6 – Calculation of stress at 0 % and at 0,1 % strain using the zero offset regression line as determined in Figure C.1b. |
| 31 | Figure C.2 – 0,2 % offset shifted regression line, the raw stress versus strain curve and the original raw data of stress versus strain Table C.7 – Linear regression equations computed for the three shifted linesand for the stress versus strain curve in the region where the lines intersect |
| 32 | Table C.8 – Calculation of strain and stress at the intersectionsof the three shifted lines with the stress strain curve |
| 33 | Table C.9 – Measured stress versus strain data and the computed stress based on a linear fit to the data in the region of interest |
| 34 | Bibliography |
