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...

Fatigue resistance of rib to deck, crossbeam to deck and deck to deck welds in orthotropic decks using structural stress

This study derives the fatigue resistance of welded details in orthotropic decks using structural stress (hot-spot stress where possible) based on tests described in literature and tests by the authors. The data are supported with linear elastic fracture mechanics simulations. Details covered are the rib to deck weld, the crossbeam to deck...

Numerical study of response behaviors of natural gas hydrate reservoir around wellbore induced by water jet slotting

The trial production of natural gas hydrate reservoirs remains poor. Reasonable reservoir reconstruction, which can improve formation permeability, is an important approach to increasing the efficiency and enhancing production. In this work, water jet slotting is proposed to reconstruct an natural gas hydrate reservoir near a wellbore. The...

Stress topology analysis for porous infill optimization

The optimization of porous infill structures via local volume constraints has become a popular approach in topology optimization. In some design settings, however, the iterative optimization process converges only slowly, or not at all even after several hundreds or thousands of iterations. This leads to regions in which a distinct binary...

Alternating optimization of design and stress for stress-constrained topology optimization

Handling stress constraints is an important topic in topology optimization. In this paper, we introduce an interpretation of stresses as optimization variables, leading to an augmented Lagrangian formulation. This formulation takes two sets of optimization variables, i.e., an auxiliary stress variable per element, in addition to a density...

Hemodynamic Study of a Patient-Specific Intracranial Aneurysm: Comparative Assessment of Tomographic PIV, Stereoscopic PIV, In Vivo MRI and Computational Fluid Dynamics

Introduction: Wall shear stress (WSS) is associated with the growth and rupture of an intracranial aneurysm. To reveal their underlying connections, many image-based computational fluid dynamics (CFD) studies have been conducted. However, the methodological validations using both in vivo medical imaging and in vitro optical flow measurements...

Numerical simulation on reflective cracking behavior of asphalt pavement

Cracks are one of the main problems that plague road workers. A correct understanding of the internal crack propagation mechanism of asphalt pavement will help road workers evaluate the road’s working status more comprehensively and make more reasonable decisions in design, construction, and maintenance work. This paper established a three...

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...

Residual ultimate strength of damaged seamless metallic pipelines with combined dent and metal loss

The combination damage induced by mechanical interference, in reality, is more likely to happen. In this paper, numerical models on pipes with combined dent and metal loss in terms of a notch are developed and validated through tests (diameter-to-thickness ratio D/t of test pipes around 21), capable of predicting the residual ultimate...

Enhancing the charge ordering temperature in thin films of Pr0.5Ca0.5MnO3 by strain

We report the effects of biaxial strain on the charge ordering temperature Tco of the mixed-valent manganite perovskite oxide Pr0.5Ca0.5MnO3. Thin films were grown on SrTiO3, which has a 1.3% larger in-plane lattice parameter. Other substrates were used for comparison. Transport measurements combined with data from electron microscopy show that...