Fatigue behaviour of toe and root stiffener cracks in stiffener-to-deck plate weld of orthotropic bridge decks

Fatigue cracks in the stiffener-to-deck plate connections of orthotropic bridge decks, initiating from the weld toe or root and propagating into the stiffener or weld throat, are experimentally and numerically studied. A statistical analysis of the structural stress is carried out using the experimental data. Automatic welded specimens show a...

Fatigue behaviour of root crack in stiffener-to-deck plate weld at crossbeam of orthotropic bridge decks

Steel Orthotropic Bridge Decks (OBDs) are widely used in long-span and movable bridges. Fatigue resistance analysis plays an important role in the design or assessment of OBDs. One possible fatigue failure is the crack initiating from the weld root of stiffener-to-deck plate connections at crossbeams. A full-scale experimental investigation...

Uniaxial tensile response and tensile constitutive model of ultra-high performance concrete containing coarse aggregate (CA-UHPC)

To establish the tensile constitutive model of ultra-high performance concrete containing coarse aggregate (CA-UHPC), monotonic and cyclic uniaxial tensile tests for CA-UHPC with fiber volume fractions of 2.5% and 2.0% were conducted. Test results showed that CA-UHPC exhibits approximately linear stress-strain relation up to the tensile strength...

Experimental investigations of welding induced temperature gradients and distortions in a segment of an OSD

Orthotropic bridge decks are susceptible to fatigue cracks which are influenced by the thickness of their components, welding procedure, type of the weld, the position of the considered detail in relation to the local loading condition and by residual stresses due to welding. The above-mentioned parameters determine the detail category for...

Ductile fracture simulation of cold-formed high strength steel using GTN damage model

The use of high strength steel (HSS) cold-formed hollow section is of significant interest in the construction sector due to competitive costs. The accurate simulation of ductile fracture failure at the micro and macro scale is critical for improving the validity of predicting structural behaviour of HSS cold-formed hollow sections and welded...

Residual stress effects on fatigue life prediction using hardness measurements for butt-welded joints made of high strength steels

The fatigue resistance of welded connections made of high strength steel (HSS) is one of the most important topics for the application of HSS in the construction sector. One of the most challenging issues is how to predict the fatigue life of welded structures with complex geometry based on the test results from relatively simple coupon...

Effects of residual stresses on fatigue crack propagation of an orthotropic steel bridge deck

Orthotropic steel decks (OSD's) are susceptible to fatigue failure due to cyclic loading. Often fatigue cracks are found in the joint between the deck plate and the trough. Due to the welding process, residual stresses are present in and around the joint. In this paper, the effect of residual stresses on the fatigue crack propagation rate has...

Three-dimensional fatigue crack propagation simulation using extended finite element methods for steel grades S355 and S690 considering mean stress effects

The assessment of fatigue crack propagation of steel structures is essential and important especially to improve the application of high strength steel in construction. The load ratio R, reflecting mean stress effects, will be changed with crack extension in the steel structures with complicated geometry. In this paper, the Walker equation is...

Fracture simulation of partially threaded bolts under tensile loading

Failure of bolts exposed to tension is generally avoided in the design of bolted connections due to the smaller deformation capacity of bolts than the connected plates. This is one of the reasons why few studies focus on the tensile failure behaviour of bolts. However, failure behaviour of bolts is essential for the advanced finite element...

Ductile damage model calibration for high-strength structural steels

Numerical analyses incorporating appropriate damage models provide an opportunity to predict the strength and deformation capacity of steel structures. This paper presents a practical calibration for the ductile damage model of S355 and high-strength steel S690Q, S700MC, S960Q based on tensile coupon test results. A combined linear and power...

Residual stress effects on fatigue crack growth rate of mild steel S355 exposed to air and seawater environments

In this paper, the parameters of fatigue crack growth rate for Q355J2 steel exposed to air and seawater were presented using the “Paris' law” based on the stress intensity factor (SIF), J-integral, crack tip opening displacement (CTOD) and crack tip opening angle (CTOA). The residual stress of a compact tension specimen is analysed by...

Resistance of cold-formed high strength steel angles

This paper describes a study of the behaviour of cold-formed high strength steel angles. Thirty-six specimens with different cold-formed angles (90°, 100°, 120°, 140°, 160°, and 170°) and different thicknesses (4 mm and 6 mm) were considered. The initial geometric imperfections of the specimens were determined using the 3D laser scanning...

Stress intensity factors of the rib-to-deck welded joint at the crossbeam conjunction in OSDs

The orthotropic steel decks (OSDs) are one of the most widely used bridge components, especially in moveable and long span bridges. Numerous cracks have been detected in this type of deck in existing bridges, mainly in the welded joints. The fatigue performance of the bridge deck dominates its design. Among them, the crack at the rib-to-deck...