IEC 61400-23:2014 defines the requirements for full-scale structural testing of wind turbine blades and for the interpretation and evaluation of achieved test results. The standard focuses on aspects of testing related to an evaluation of the integrity of the blade, for use by manufacturers and third party investigators. The following tests are considered in this standard: – static load tests; – fatigue tests; – static load tests after fatigue tests; – tests determining other blade properties. The purpose of the tests is to confirm to an acceptable level of probability that the whole population of a blade type fulfils the design assumptions.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 6<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 1 Scope 2 Normative references <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 4 Notation 4.1 Symbols 4.2 Greek symbols 4.3 Subscripts 4.4 Coordinate systems <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 5 General principles 5.1 Purpose of tests Figures Figure 1 \u2013 Chordwise (flatwise, edgewise) coordinate system Figure 2 \u2013 Rotor (flapwise, lead-lag) coordinate system <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 5.2 Limit states 5.3 Practical constraints 5.4 Results of test <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 6 Documentation and procedures for test blade <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 7 Blade test program and test plans 7.1 Areas to be tested 7.2 Test program 7.3 Test plans 7.3.1 General 7.3.2 Blade description <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 7.3.3 Loads and conditions 7.3.4 Instrumentation 7.3.5 Expected test results 8 Load factors for testing 8.1 General 8.2 Partial safety factors used in the design 8.2.1 General 8.2.2 Partial factors on materials <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 8.2.3 Partial factors for consequences of failure 8.2.4 Partial factors on loads 8.3 Test load factors 8.3.1 Blade to blade variation 8.3.2 Possible errors in the fatigue formulation Tables Table 1\u00a0\u2013 Recommended values for (ef for different number of load cycles <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 8.3.3 Environmental conditions 8.4 Application of load factors to obtain the target load <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 9 Test loading and test load evaluation 9.1 General 9.2 Influence of load introduction 9.3 Static load testing <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 9.4 Fatigue load testing <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 10 Test requirements 10.1 General 10.1.1 Test records 10.1.2 Instrumentation calibration 10.1.3 Measurement uncertainties 10.1.4 Root fixture and test stand requirements 10.1.5 Environmental conditions monitoring <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 10.1.6 Deterministic corrections 10.2 Static test 10.2.1 General 10.2.2 Static load test <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 10.2.3 Strain measurement 10.2.4 Deflection measurement 10.3 Fatigue test 10.4 Other blade property tests 10.4.1 Blade mass and center of gravity <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 10.4.2 Natural frequencies 10.4.3 Optional blade property tests 11 Test results evaluation 11.1 General 11.2 Catastrophic failure <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 11.3 Permanent deformation, loss of stiffness or change in other blade properties 11.4 Superficial damage 11.5 Failure evaluation 12 Reporting 12.1 General <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 12.2 Test report content 12.3 Evaluation of test in relation to design requirements <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | Annex A (informative) Guidelines for the necessity of renewed static and fatigue testing Table A.1 \u2013 Examples of situations typically requiring or not requiring renewed testing <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | Annex B (informative) Areas to be tested <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | Annex C (informative) Effects of large deflections and load direction Figure C.1 \u2013 Applied loads effects due to blade deformation and angulation <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Annex D (informative) Formulation of test load D.1 Static target load D.2 Fatigue target load Figure D.1 \u2013 Polar plot of the load envelope from a typical blade <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Figure D.2 \u2013 Design FSF Figure D.3 \u2013 Area where design FSF is smaller than 1,4 (critical area) <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | D.3 Sequential single-axial, single location D.4 Multi axial single location Figure D.4 \u2013 rFSF and critical areas, sequential single-axial test <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | Figure D.5 \u2013 rFSF and critical area, multi axial test <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Annex E (informative) Differences between design and test load conditions E.1 General E.2 Load introduction E.3 Bending moments and shear E.4 Flapwise and lead-lag combinations Figure E.1 \u2013 Difference of moment distribution for target and actual test load <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | E.5 Radial loads E.6 Torsion loads E.7 Environmental conditions E.8 Fatigue load spectrum and sequence <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | Annex F (informative) Determination of number of load cycles for fatigue tests F.1 General F.2 Background F.3 The approach used Table F.1 \u2013 Recommended values for (ef for different number of load cycles <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | Figure F.1 \u2013 Simplified Goodman diagram <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | Table F.2 \u2013 Expanded recommended values for (ef for different number of load cycles <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | Figure F.2 \u2013 Test load factor (ef for different number of load cycles in the test <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Wind turbines – Full-scale structural testing of rotor blades<\/b><\/p>\n |