BS EN 61788-18:2013:2014 Edition
$167.15
Superconductivity – Mechanical properties measurement. Room temperature tensile test of Ag- and/or Ag alloy-sheathed Bi-2223 and Bi-2212 composite superconductors
| Published By | Publication Date | Number of Pages |
| BSI | 2014 | 42 |
IEC 61788-18:2013 specifies a test method detailing the tensile test procedures to be carried out on Ag/Bi-2223 and Ag/Bi-2212 superconductive composite wires at room temperature. This test is used to measure the modulus of elasticity and to determine the 0,2 % proof strength. When the 0,2 % proof strength could not be determined due to earlier failure, the stress level at apparent strains of 0,05 %, 0,1 %, 0,15 %, 0,2 %, 0,25 % with increment of 0,05 % is measured. The values for elastic limit, fracture strength, percentage elongation after fracture and the fitted type of 0,2 % proof strength serve only as a reference. The sample covered by this test procedure should have a round or rectangular cross-section with an area of 0,3 mm 2 to 2,0 mm 2 (corresponding to the tape-shaped wires with width of 2,0 mm to 5,0 mm and thickness of 0,16 mm to 0,4 mm). Key words: superconductivity, mechanical properties measurement
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 4 | Foreword Endorsement notice |
| 5 | Annex ZA (normative) Normative references to international publications with their corresponding European publications |
| 6 | English CONTENTS |
| 8 | INTRODUCTION |
| 9 | 1 Scope 2 Normative references 3 Terms and definitions |
| 11 | 4 Principle 5 Apparatus 5.1 General 5.2 Testing machine 5.3 Extensometer 6 Specimen preparation 6.1 General |
| 12 | 6.2 Length of specimen 6.3 Removing insulation 6.4 Determination of cross-sectional area (S0) 7 Testing conditions 7.1 Specimen gripping 7.2 Setting of extensometer 7.3 Testing speed 7.4 Test |
| 13 | Figures FigureĀ 1 ā Typical stress-strain curve and definition of modulus of elasticity and 0,2Ā % proof strengths of an Ag/Bi-2223 wire externally laminated by brass foil |
| 14 | 8 Calculation of results 8.1 Modulus of elasticity (E) FigureĀ 2 ā Typical stress-strain curve of an Ag/Bi-2223 wire where the 0,2Ā % proof strengths could not be determined and definition of tensile stresses at specified strains |
| 15 | 8.2 0,2 % proof strength (Rp 0,2) 8.3 Tensile stress at specified strains (RA) |
| 16 | 8.4 Fracture strength (Rf) 9 Uncertainty of measurement 10 Test report 10.1 Specimen |
| 17 | 10.2 Results 10.3 Test conditions |
| 18 | Annex A (informative) Additional information relating to Clauses 1 to 14 FigureĀ A.1 ā Low mass Siam twin type extensometer with a gauge length of ~ 12,3 mm (total mass ~ 0,5 g) |
| 19 | Figure A.2 ā Low mass double extensometer with a gauge length of ~ 25,6 mm (total mass ~ 3 g) |
| 20 | FigureĀ A.3 ā An example of the extensometer provided with balance weight and vertical specimen axis |
| 21 | FigureĀ A.4 ā Original raw data of an Ag/Bi-2223 wire measurement in form of load and displacement graph |
| 22 | FigureĀ A.5 ā Typical stress versus strain of an Ag/Bi-2223 wire up to the elastic limit corresponding to the transition region from elastic to plastic deformation (point G) |
| 25 | Tables TableĀ A.1 ā Results of relative standard uncertainty values achieved on different Ag/Bi-2223 wires during the international round robin tests |
| 26 | TableĀ A.2 ā Selected data for F test for E0 of Sample E bare wire TableĀ A.3 ā Results of F-test for the variations of E0 of four kinds of Bi-2223 wires |
| 28 | Annex B (informative) Uncertainty considerations |
| 29 | TableĀ B.1 ā Output signals from two nominally identical extensometers TableĀ B.2 ā Mean values of two output signals TableĀ B.3 ā Experimental standard deviations of two output signals TableĀ B.4 ā Standard uncertainties of two output signals |
| 30 | TableĀ B.5 ā Coefficient of variations of two output signals |
| 32 | Annex C (informative) Specific examples related to evaluation of uncertainties for Ag/Bi-2223 and Ag/Bi-2212 wires |
| 33 | FigureĀ C.1 ā Measured stress versus strain curve for Bi-2223 wire |
| 34 | TableĀ C.1. ā Load cell specifications according to manufacturerās data sheet |
| 35 | TableĀ C.2 ā Uncertainties from various factors for stress measurement |
| 37 | TableĀ C.3 ā Uncertainties with respect to measurement of strain measurement TableĀ C.4 ā Summary of evaluated uncertainties caused by various factors |
| 38 | TableĀ C.5 ā Results of uncertainty evaluation for the modulus of elasticity (E0Ā =Ā 86,1 GPa) as a function of initial cross head rate |
| 39 | TableĀ C.6 ā Uncertainties from various factors for stress measurement Table C.7 ā Results of uncertainty evaluation for the stress (R = 42,5 MPa) as a function of initial strain rate |
| 40 | Bibliography |
