BSI PD 6695-1-9:2008
$142.49
Recommendations for the design of structures to BS EN 1993-1-9
| Published By | Publication Date | Number of Pages |
| BSI | 2008 | 26 |
This Published Document gives non-contradictory complementary information for use in the UK with BS EN 1993-1-9 and its UK National Annex.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 3 | Contents 1 Scope 1 2 Material and execution tolerances and inspection 1 3 Derivation of specific fatigue loading models 4 4 Determining fatigue strengths from tests 4 5 Assessment methods for fatigue design 6 6 Use of nominal, modified nominal and geometric stress ranges 8 7 Stress concentration factors 16 8 Determination of fatigue load parameters and verification formats 17 Bibliography 20 List of figures Figure 1 – Method of indicating quality requirements higher than Fat 56 on drawings when using BS EN 1090-2 for execution 3 Figure 2 – Effect of stress concentrations on nominal and modified nominal stresses 10 Figure 3 – Example of hot spot stresses in a tubular lattice joint – load applied in the brace 14 Figure 4 – Typical stress concentration factors from radiused corners in flat plate (from BS 5400-10:1980) 16 Figure 5 – Procedure on cycle counting using the reservoir method 19 List of tables Table 1 – Fatigue class requirement in BS 5400-6 corresponding to minimum required detail category in BS EN 1993-1-9 2 Table 2 – Fatigue class requirement corresponding to minimum required detail category in BS EN 1993-1-9 2 |
| 4 | Foreword |
| 5 | 1 Scope 2 Material and execution tolerances and inspection [BS EN 1993-1-9:2005, 1.1(2)] 2.1 General 2.2 Implementation with materials and specification to BS 5400-6 |
| 6 | Table 1 Fatigue class requirement in BS 5400-6 corresponding to minimum required detail category in BS EN 1993-1-9 2.3 Implementation with materials and workmanship specification to BS EN 1090-21) Table 2 Fatigue class requirement corresponding to minimum required detail category in BS EN 1993-1-9 |
| 7 | Figure 1 Method of indicating quality requirements higher than Fat 56 on drawings when using BS EN 1090-2 for execution 2.4 Assurance of quality |
| 8 | 3 Derivation of specific fatigue loading models [BS EN 1993-1-9:2005, 2(2)] 4 Determining fatigue strengths from tests [BS EN 1993-1-9:2005, 2(4)] 4.1 General 4.2 Test specimens 4.3 Testing conditions |
| 9 | 4.4 Instrumentation 4.5 Loading history 4.6 Monitoring of test 4.7 Analysis of results a) lack fit and residual stresses; b) dimensional tolerances and scale effects; c) manufacturing procedures; d) material and workmanship imperfections, taking into account the acceptance criteria and methods of inspection in the execution standard; e) environment. |
| 10 | 5 Assessment methods for fatigue design [BS EN 1993-1-9:2005, 3(1)] 5.1 General 5.2 Safe life method 5.3 Damage tolerant method |
| 11 | 5.4 Consequence class a) by applying different multiplication factors on actions (1,1, 1,0 and 0,9 for “high”, “medium” and “low” respectively; see BS EN 1990:2002, Table B.3); b) by applying different levels of checking of designs (third party, independent in-house and self checking for “high”, “medium” and “low” respectively; see BS EN 1990:2002, Table B.4); c) by applying different levels of inspection during execution (third party, in-house procedures, and self inspection for “high”, “medium” and “low” respectively; see BS EN 1990:2002, Table B.5). |
| 12 | 5.5 Partial factor gMf 6 Use of nominal, modified nominal and geometric stress ranges [BS EN 1993-1-9:2005, Clause 5 and Clause 6] 6.1 General 6.2 Guidance on global analysis |
| 13 | 6.3 Nominal stresses 6.3.1 General a) The details associated with the site are in reasonable agreement with the appropriate detail category requirements in BS EN 1993-1-9. b) In the event that a) does not apply, the detail category has been established by test in accordance with National Annex recommendations and the results have been expressed in terms of the nominal stresses. c) Gross geometrical effects such as those detailed in the National Annex are not present in the vicinity of the initiation site. d) The crack initiation site is located at the root of a fillet weld or a partial penetration butt weld. e) The crack location is in the thread or under the head of a bolt in axial tension and/or bending. |
| 14 | Figure 2 Effect of stress concentrations on nominal and modified nominal stresses |
| 15 | 6.3.2 Derivation of nominal stresses 6.3.2.1 Structural models using beam elements 6.3.2.2 Structural models using membrane, shell or solid elements |
| 16 | 6.3.3 Modified nominal stresses 6.3.3.1 Range of use of modified nominal stress a) gross changes in cross-section shape, e.g. at cut-outs or re-entrant corners; b) gross changes in stiffness around the member cross-section at unstiffened angled junctions between open or hollow sections; c) changes in direction or alignment from those given in detail category tables (Tables 8.1 to 8.10) in BS EN 1993-1-9:2005; d) shear lag and distortion in wide plated or hollow members; e) non-linear out-of-plane bending effects in slender components such as flat plates where the static stress is close to the elastic critical stress, e.g. tension field in webs. 6.3.3.2 Derivation of modified nominal stresses – Structural models using beam elements a) standard solutions for stress concentration factors; b) substructuring of the surrounding geometry using shell elements taking into account geometrical discontinuities that need to be modelled, and applying the nominal stresses to the boundaries; c) measurement of elastic strains on a physical model which incorporates the gross geometrical discontinuities, but excludes those features already incorporated within the detail category [see item b)]. 6.3.3.3 Derivation of modified nominal stresses – Structural models using membrane, shell or solid elements a) Local stress concentrations such as the classified detail and the weld profile already included in the detail category should be omitted. b) The mesh in the region of the initiation site should be fine enough to predict the general stress field around the site accurately but without incorporating the effects in a). |
| 17 | 6.3.4 Geometrical (hot spot) stresses 6.3.4.1 Range of use of geometrical (hot spot) stresses a) the initiation site is a weld toe in a joint with complex geometry where the nominal stress is not clearly defined; or b) a hot spot detail category has been established by test where the results have been expressed in terms of the hot spot stress, for the appropriate loading mode. 6.3.4.2 Derivation of geometrical (hot spot) stresses |
| 18 | Figure 3 Example of hot spot stresses in a tubular lattice joint – load applied in the brace |
| 20 | 7 Stress concentration factors (BS EN 1993-1-9:2005, Clause 6) Figure 4 Typical stress concentration factors from radiused corners in flat plate (from BS 5400-10:1980) |
| 21 | 8 Determination of fatigue load parameters and verification formats [BS EN 1993-1-9:2005, Annex A] 8.1 General |
| 22 | 8.2 Application of the cumulative damage method in BS EN 1993-1-9:2005, Annex A 8.2.1 Fatigue loading 8.2.2 l factor 8.2.3 Particular points when applying BS EN 1993-1-9:2005, Annex A 8.2.3.1 BS EN 1993-1-9:2005, A.1 8.2.3.2 BS EN 1993-1-9:2005, A.2 8.2.3.3 BS EN 1993-1-9:2005, A.3 8.2.3.4 BS EN 1993-1-9:2005, A.4 |
| 23 | Figure 5 Procedure on cycle counting using the reservoir method |
| 24 | Bibliography |
