Fatigue design of steel and composite structures : Eurocode 3: Design of Steel Structures Part 1-9 – Fatigue Eurocode 4: Design of Composite Steel and Concrete Structures

294 Pages·2018·12.99 MB·English

by  Alain Nussbaumer, Luís Borges, Laurence Davaine

Table of Contents
Cover
FOREWORD
PREFACE
Chapter 1: INTRODUCTION
1.1 BASIS OF FATIGUE DESIGN IN STEEL STRUCTURES
1.2 DAMAGE EQUIVALENT FACTOR CONCEPT
1.3 CODES OF PRACTICE
1.4 DESCRIPTION OF THE STRUCTURES USED IN THE WORKED EXAMPLES
Chapter 2: APPLICATION RANGE AND LIMITATIONS
2.1 INTRODUCTION
2.2 MATERIALS
2.3 CORROSION
2.4 TEMPERATURE
2.5 LOADING RATE
2.6 LIMITING STRESS RANGES
Chapter 3: DETERMINATION OF STRESSES AND STRESS RANGES
3.1 FATIGUE LOADS
3.2 DAMAGE EQUIVALENT FACTORS
3.3 CALCULATION OF STRESSES
3.4 MODIFIED NOMINAL STRESSES AND CONCENTRATION FACTORS
3.5 GEOMETRIC STRESSES (STRUCTURAL STRESS AT THE HOT SPOT)
3.6 STRESSES IN ORTHOTROPIC DECKS
3.7 CALCULATION OF STRESS RANGES
3.8 MODIFIED NOMINAL STRESS RANGES
3.9 GEOMETRIC STRESS RANGES
Chapter 4: FATIGUE STRENGTH
4.1 INTRODUCTION
4.2 FATIGUE DETAIL TABLES
4.3 DETERMINATION OF FATIGUE STRENGTH OR LIFE BY TESTING
Chapter 5: RELIABILITY AND VERIFICATION
5.1 GENERALITIES
5.2 STRATEGIES
5.3 PARTIAL FACTORS
5.4 VERIFICATION
Chapter 6: BRITTLE FRACTURE
6.1 INTRODUCTION
6.2 STEEL QUALITY
6.3 RELATIONSHIP BETWEEN DIFFERENT FRACTURE TOUGHNESS TEST
RESULTS
6.4 FRACTURE CONCEPT IN EN 1993-1-10
6.5 STANDARDISATION OF CHOICE OF MATERIAL: MAXIMUM ALLOWABLE
THICKNESSES
REFERENCES
Annex A: STANDARDS FOR STEEL CONSTRUCTION
Annex B: FATIGUE DETAIL TABLES WITH COMMENTARY
B.1 PLAIN MEMBERS AND MECHANICALLY FASTENED JOINTS (EN 1993-1-9,
TABLE 8.1)
B.2 WELDED BUILT-UP SECTIONS (EN 1993-1-9, TABLE 8.2)
B.3 TRANSVERSE BUTT WELDS (EN 1993-1-9, TABLE 8.3)
B.4 ATTACHMENTS AND STIFFENERS (EN 1993-1-9, TABLE 8.4)
B.5 LOAD CARRYING WELDED JOINTS (EN 1993-1-9, TABLE 8.5)
B.6 HOLLOW SECTIONS (T ≤ 12.5 mm) (EN 1993-1-9, Table 8.6)
B.7 LATTICE GIRDER NODE JOINTS (EN 1993-1-9, TABLE 8.7)
B.8 ORTHOTROPIC DECKS – CLOSED STRINGERS (EN 1993-1-9, TABLE 8.8)
B.9 ORTHOTROPIC DECKS – OPEN STRINGERS (EN 1993-1-9, TABLE 8.9)
B.10 TOP FLANGE TO WEB JUNCTION OF RUNWAY BEAMS (EN 1993-1-9,
TABLE 8.10)
B.12 TENSION COMPONENTS
B.11 DETAIL CATEGORIES FOR USE WITH GEOMETRIC (HOT SPOT) STRESS
METHOD (EN 1993-1-9, TABLE B1)
B.13 REVIEW OF ORTHOTROPIC DECKS DETAILS AND STRUCTURAL
ANALYSIS
Annex C: MAXIMUM PERMISSIBLE THICKNESSES TABLES
C.1 MAXIMUM PERMISSIBLE VALUES OF ELEMENT THICKNESS T IN MM
(EN 1993-1-10, TABLE 2.1)
C.2 MAXIMUM PERMISSIBLE VALUES OF ELEMENT THICKNESS T IN MM
(EN 1993-1-12, TABLE 4)
End User License Agreement
List of Tables
Chapter 1: INTRODUCTION
Table 1.1 – Overview and changes in the transition from ENV to EN versions of the
various Eurocode 3 and Eurocode 4 parts
Table 1.2 – Definition of consequence classes (adapted from EN 1990, Table B1)
Table 1.3 – Suggested criteria for service categories (from EN 1090-2, Table B.1)
Table 1.4 – Suggested criteria for production categories (from EN 1090-2, Table B.2)
Table 1.5 – Recommendation for the determination of the execution classes (from EN
1090-2, Table B.3)
Table 1.6 – Main weld requirements, extracts from EN 1090-2
Table 1.7 – f and f according to the plate thickness for steel grade S355
y u
Chapter 3: DETERMINATION OF STRESSES AND STRESS RANGES
Table 3.1 – Overview of Eurocode standards to assess the fatigue strength of different
structures
Table 3.2 – Set of frequent lorries for road bridges, fatigue load model 2 (source EN
1991-2, Table 4.6)
Table 3.3 – Indicative numbers of heavy vehicles expected per year and per slow lane
(source EN 1991-2)
Table 3.4 – Set of equivalent lorries for road bridges, fatigue load model 4 (source EN
1991-2, Table 4.7)
Table 3.5 – Load model 71 and SW/0
Table 3.6 – Classification of the fatigue actions from cranes into service classes
according to EN 13001-1
Table 3.7 – Determination of the exposure class of tension components
Table 3.8 – Partial damage equivalent factor λ value for road bridge detail
1
Table 3.9 – Partial damage equivalent factor λ value for road bridge detail
max
Table 3.10 – Summary of damage equivalent factor values for road bridge example
Table 3.11 – Coefficients k for secondary stresses in members of open sections
1
(source Table 5.4 from EN 1993-6)
Table 3.12 – λ -values according to the classification of cranes (source Table 2.12
i
from EN 1991-3)
Table 3.13 – Values of β and ϕ (EN 1991-3, Table 2.5)
2 2,min
Table 3.14 – Summary of the moments and stress ranges in the runway beam
Table 3.15 – Summary of the additional moments and stress ranges in the runway beam
with cranes occasionally acting together
Chapter 4: FATIGUE STRENGTH
Table 4.1 – Modified strength curves, original and alternatives values
Table 4.2 – Influence of length on the detail category for a longitudinal attachment
(extract from Table 8.4 EN 1993-1-9)
Table 4.3 – Groups of tension components and corresponding detail categories for
fatigue strength
Chapter 5: RELIABILITY AND VERIFICATION
Table 5.1 – Indicative design working life according to EN 1990, including additional
information
Table 5.2 – Recommended values for the partial factor γ
Mf
Table 5.3 – Damage analysis of a test result from Fisher et al (1993) with only 0.01 %
of stress ranges above CAFL
Table 5.4 – Damage sum for FLM4 traffic
Table 5.5 – Maximum stress limits f for service conditions (from EN 1993-1-11)
SLS
Table 5.6 – Summary of the detail fatigue verifications.
Table 5.7 – Summary of the detail fatigue verifications for two cranes working together
Chapter 6: BRITTLE FRACTURE
Table 6.1 – Definition of steel quality according to European codes
List of Illustrations
TERMINOLOGY
Figure 0.1 – Orientation of the attachment with respect to the main force
Chapter 1: INTRODUCTION
Figure 1.1 – Possible location of a fatigue crack in a road bridge (TGC 10, 2006)
Figure 1.2 – Definition of stresses and influence of tensile residual stresses (TGC 10,
2006)
Figure 1.3 – Fatigue test results of structural steel members, plotted in double logarithm
scale, carried out under constant amplitude loading (TGC 10, 2006)
Figure 1.4 – Illustration of generic variable amplitude stress-time history (ECCS,
2000)
Figure 1.5 – Example of stress spectrum and corresponding histogram (ECCS, 2000)
Figure 1.6 – Example of measured stress history on a road bridge (Schumacher and
Blanc, 1999)
Figure 1.7 – Example of stress range histogram from two weeks measurements on a
road bridge (Schumacher and Blanc, 1999)
Figure 1.8 – Damage accumulation scheme
Figure 1.9 – Influence of stress ranges below the constant amplitude fatigue limit, Δσ ,
D
and the cut-off limit, Δσ (TGC 10, 2006)
L
Figure 1.10 – Damage equivalent factor (Hirt, 2006)
Figure 1.11 – Standard system for steel structures (Schmackpfeffer et al, 2005) and
composite steel and concrete structures
Figure 1.12 – Side view of road bridge with span distribution
Figure 1.13 – Cross section of road bridge with lane positions
Figure 1.14 – Cross frame on supports
Figure 1.15 – Structural steel distribution (half length of the road bridge)
Figure 1.16 – Detailed view of longitudinal stiffener
Figure 1.17 – Side view of the example chimney
Figure 1.18 – Anchor bolts at +0.350 m (plan view)
Figure 1.19 – Drawing of bottom part of chimney with manhole position, section and
top view, ground plate with anchor bolts at +0.350 m
Figure 1.20 – Relevant bolted flange connection between two sections at +11.490 m
(remark: this flange design corresponds to standard practice and does not represent
optimum design; an improved design is possible)
Figure 1.21 – Ground plate with anchor bolts at +0.350 m (section view)
Figure 1.22 – Crane supporting structure
Figure 1.23 – Cross section of the runway beam
Chapter 2: APPLICATION RANGE AND LIMITATIONS
Figure 2.1 – Hybrid girder stress-strain fatigue cycles
Chapter 3: DETERMINATION OF STRESSES AND STRESS RANGES
Figure 3.1 – Fatigue load model 3 for a road bridges according to EN 1991-2
Figure 3.2 – Load arrangements to obtain the relevant vertical actions on the runway
beams (from EN 1991-3)
Figure 3.3 – Two stress cycles rising from one crane working cycle
Figure 3.4 – Chimney 1st mode correlation length (EN 1991-1-4)
Figure 3.5 – Damage equivalent partial factor λ for road and rail bridges as a function
1
of the critical influence line length L (Nussbaumer, 2006)
Figure 3.6 – Definition of mid-span and intermediate support regions
Figure 3.7 – λ factor for railway bridges
1
Figure 3.8 – λ factor for railway bridges
2
Figure 3.9 – λ factor for shear studs in railway bridges
v,1
Figure 3.10 – Gaussian distribution standardised as relative stress range for crane
supporting structures (tracks) (IIW, 2009)
Figure 3.11 – Critical fatigue locations to be verified
Figure 3.12 – Example of detail (from EN 1993-1-9, Table 8.5, detail 6, end of
coverplate) and fatigue crack that developed at this detail
Figure 3.13 – Wide flange beam in bending with a structural detail on its flange
Figure 3.14 – Relevant stresses in fillet welds (double-sided is represented), also
valid for partial penetration welds
Figure 3.15 – Partial penetration T-butt joints or fillet welded joint (double-sided)
Figure 3.16 – Fillet welded double-sided lap joint
Figure 3.17 – Positive eccentricity in a K-joint made of circular hollow sections
(CIDECT, 2001)
Figure 3.18 – Plane frame analysis according to CIDECT (CIDECT, 2001)
Figure 3.19 – Plane frame analyses and joint modelling assumptions (Walbridge 2005)
Figure 3.20 – Geometric stress concentration in the vicinity of a hole
Figure 3.21 – Geometric stress concentration factors at holes and unreinforced
apertures (based on net stress at X-X) adapted from BS 7608 (BS 7608, 1993)
Figure 3.22 – Geometric stress concentration factors at re-entrant corners (based on net
stress at X-X), adapted from (BS 7608, 1993)
Figure 3.23 – Possible cases of axial misalignment between plates
Figure 3.24 – Case of angular misalignment
Figure 3.25 – Reinforcement of the manhole edge and positions of computed modified
stresses
Figure 3.26 – View of welded transverse attachments with different weld shapes, all
having the same structural stress at the hot spot, σ
hs
Figure 3.27 – Illustration of concept of extrapolation of surface stresses to weld toe
(Schumacher, 2003)
Figure 3.28 – Types a and b of structural stress at the hot spot obtained from FEA by
extrapolation on surface using solid elements (b) and shell elements (c) (extracted from
(Niemi et al, 2006))
Figure 3.29 – Typical orthotropic steel deck with crossbeams and main girder
(Leendertz, 2008)
Figure 3.30 – Representation of the reduced stress range for non-welded details
Figure 3.31 – Comparison between different recommendations for computing reduced
stress ranges correction factors
Figure 3.32 – Comparison between the stress ranges in a non-preloaded and a
preloaded bolted joints
Figure 3.33 – Evolution between external load and bolt tension force for a non
preloaded and a preloaded bolt (NCHRP, 2002)
Figure 3.34 – Geometry and notations for L-joint part of a bolted ring connection
Figure 3.35 – Possible fatigue crack locations in partial penetration a T-joints, butt or
fillet welded (double-sided)
Figure 3.36 – Differentiation between proportional and non-proportional cyclic
loadings and further separation of the different cases (Radaj, 2003)
Figure 3.37 – Stresses at mid-span in a simply supported beam due to the passage of a
single load
Figure 3.38 – Design value of the bending moment for the basic SLS combination of
non-cyclic loads
Figure 3.39 – Stress ranges for the upper face of the lower flange
Figure 3.40 – Shear connectors row spacing (density) for one of the steel flanges
Figure 3.41 – Shear stress ranges at the steel-concrete interface along one of the steel
upper flange
Figure 3.42 – Example of detail with additional geometric stress concentration due to
misalignment, or say eccentricity
Figure 3.43 – Uniplanar girder and design load situation (constant amplitude load
ranges)
Figure 3.44 – Internal load condition of joint 6 (axial forces and bending moments
ranges)
Figure 3.45 – Two basic fatigue load-cases of joint 6
Chapter 4: FATIGUE STRENGTH
Figure 4.1 – Set of fatigue strength curves for direct (normal) stress ranges
Figure 4.2 – Set of fatigue strength curves for tubular lattice girder node joints (details
from Table 8.7)
Figure 4.3 – Set of fatigue strength curves for shear stress ranges
Figure 4.4 – The two alternative fatigue strength curves for a particular detail category
45* under direct (normal) stress ranges
Figure 4.5 – Bolted connections in shear, categories, area of load transfer and possible
location of fatigue crack (from ESDEP courses (ESDEP, 1995))
Figure 4.6 – Different possible fit-up cases in bolted connections in tension with (a)
best, (c) worst, because of prying forces (from ESDEP courses (ESDEP, 1995))
Figure 4.7 – Different types of welded details
Figure 4.8 – Total attachment length, L, in transverse attachments
Figure 4.9 – Chimney socket joint fatigue detail (EN 1993-1-9, Table 8.5)
Figure 4.10 – Fatigue detail for bolt in tension in chimney socket joint (EN 1993-1-9,
Table 8.1)
Figure 4.11 – Chimney bottom socket joint, with possible fatigue crack locations
Figure 4.12 – Geometry of runway beam of crane
Figure 4.13 – Typical orthotropic steel deck crack locations, adapted from EN 1993 –
2 (detail numbering corresponds to the one in Table B.13)
Figure 4.14 – Fatigue strength curves for tension components
Chapter 5: RELIABILITY AND VERIFICATION
Figure 5.1 – Schematic of fatigue reliability assuming damage tolerant and safe life
methods and a failure with high consequence
Figure 5.2 – Reliability index, β, as a function of the choice of the verification method
(strategy) and the consequence of failure
Figure 5.3 – Verification using the fatigue limit
Figure 5.4 – Chimney welded stiffener tee-butt joint (Table 8.5)
Figure 5.5 – 3D views of a) the road bridge box beam and location of longitudinal
attachment, b) its equivalent in the detail category tables
Figure 5.6 – Verification of single stress ranges related to the shear connection
Figure 5.7 – Fatigue strength curves for tension components
Figure 5.8 – (a) typical crane runway for top running overhead travelling crane, (b)
detail of runway under bending and local stresses due to wheel passage
Figure 5.9 – Verification of the interaction criterion for the shear connection
Chapter 6: BRITTLE FRACTURE
Figure 6.1 – Standard ISO specimen geometry with a V-notch for the Charpy test (TGC
10, 2006)
Figure 6.2 – Example of Charpy impact test results at different temperatures and
transition curve (S355N steel) (Banz and Nussbaumer, 2001) - 1) Brittle behaviour
(lower shelf); 2) Transition region; 3) Ductile behaviour (upper shelf)
Figure 6.3 – Schematic difference between static and impact tests transition curves for
a structural steel (TGC 10, 2006)
Figure 6.4 – Toughness-temperature curve and related load-deformation curves for
tension members using various parameters for toughness properties for ferritic steels
(Sedlacek et al, 2002)
Figure 6.5 – Temperature shift between CVN and toughness tests (JRC, 2008)
Figure 6.6 – Predicted static fracture toughness for the S355 N steel from (Banz and
Nussbaumer, 2001)
Figure 6.7 – Verification scheme based on temperatures, with example values for
temperature shifts (Sedlacek et al, 2002)
Figure 6.8 – Flaw in a plate (non-welded details), modelled as an initial crack with
dimensions a and c (JRC, 2008)
0 0
Figure 6.9 – Schematic of the method and main parameters in the fracture mechanics
safety verification (Schmackpfeffer et al, 2005)
Figure 6.10 – Tensile stresses in the upper flange for the determination of the steel
quality
Figure 6.11 – Comparison between results from crack growth computations for various
typical details in steel S355 and ΔT limiting curve obtained with σ = 0.75 f (JRC,
σ Ed y
2008)
Figure 6.12 – Maximum permissible thickness of an element, influence of stress level
and of the subgrade, for steel grade S235
Figure 6.13 – Maximum permissible thickness of an element, influence of steel grade,
from S2365 to S690, for selected subgrades