In this paper, Taylor’s floating air-backed plate (ABP) model is extended to the case of a submerged water-backed (WBP) within acoustic range. The solution WBP cast into same format as that ABP with modified fluid-structure interaction (FSI) parameter, which allows unified analysis and using set formulas. influence back conditions on fluid structural dynamics, including cavitation, systematically investigated. Asymptotic limits are mathematically identified physically interpolated. Results...

There is an increasing interest in the use of composites for marine/naval structures to reduce weight and maintenance cost, improve hydrodynamic and/or structural performance. In particular, recent works suggest that a lightweight, soft core layer can significantly load transfer back sandwich structure when subjected shock or impulse loads. The objective this work investigate role fluid-structure interaction (FSI) shock-bubble transient response composite during underwater explosions...

Recently, there is an increased interest to use composites as alternative materials for naval structures. In addition the important advantage of weight reduction, deformation structure can be tailored improve hydrodynamic and/or elastodynamic performance. For propulsors in particular, hydroelastic tailoring help reduce load variations, delay cavitation inception, and propeller efficiency by allowing each blade automatically adjust its shape with local inflow. this work, a coupled boundary...

Abstract Interactions between deformable composite structures and compressible multiphase flow are common for many marine/submarine problems. Recently, there has been an increased interest in the application of marine industry (e.g. propulsion system, ship hulls, platforms, turbines, etc) to take advantage their high stiffness weight strength ratios, impact/shock resistance characteristics. It is therefore important evaluate performance subject dynamic loads. In this paper, a coupled...

In recent years, there has been an increased interest in the use of advanced composites marine applications. It shown that by exploiting inherent anisotropic nature material, fiber-reinforced composite structures can be tailored to allow automatic, passive, three-dimensional (3D) adaptive/morphing capabilities such they outperform their rigid counterparts both hydrodynamically and structurally. Much current research on shock response focuses air-backed with fixed-fixed or simply supported...

Abstract Most coiled tubing (CT) string failures in the field can be traced back to some initial defects, such as mechanical damage, a corrosion pit, manufacturing defect, etc. Because of ductility CT, introduction these defects doesn’t normally cause failure at onset. However, over course service life, evolve or grow until they reach critical stage, leading eventual failure. To assess serviceability CT string, industry has largely relied on periodic pipe inspection using magnetic flux...

Abstract Mechanical defects, such as manufacturing imperfections, grinding marks, corrosion pits, slip kinking, gouges, etc, whether occurred in the factory or field, can be readily found on CT strings. Extensive studies have demonstrated detrimental effects of mechanical over integrity coiled tubing, both lab and field. Researchers field been proposing theoretical models for severity assessment particularly it relates to remaining fatigue life. For models, defect sizing is usually a...

In this work, a numerical method is presented for the hydrodynamic and hydroelastic analysis of Newton-Rader (NR) propellers (Newton & Rader 1961). The NR are well-known series three-bladed specifically designed, extensively tested, well documented high-speed crafts. tests were conducted at Vosper Cavitation Tunnel, exhibit both face back cavitation patterns predicted fully wetted cavitating performance agreed with experimental measurements. results indicate that can achieve high...

This paper investigated the influence of interfacial bonding on transient response sandwich plates subject to underwater explosions. It was found that un-bonded receive lower impact energy, and are able dissipate more energy through plastic deformation foam core, than perfectly bonded plates. Consequently, de-bonding leads net transfer from explosion target structure although it also increases structural due stiffness reduction. Parametric studies showed advantage (diminishing transfer) is...

This paper investigated the influence of interfacial bonding on transient response sandwich plates subject to underwater explosions. It was found that un-bonded receive lower impact energy, and are able dissipate more energy through plastic deformation foam core, than perfectly bonded plates. Consequently, de-bonding leads net transfer from explosion target structure although it also increases structural due stiffness reduction. Parametric studies showed advantage (diminishing transfer) is...

Abstract In 2018, coiled tubing (CT) interventions in the Norwegian sector witnessed a rise adoption of high-grade quench and tempered (Q&T) CT strings. These primarily focused on multistage fracturing stimulation, involving tasks such as sliding sleeve manipulation, fishing, and, wells aged, underbalanced cleanouts using nitrified fluids due to reservoir depletion. Recent revealed significant wellbore abrasion, manifesting longitudinal grooves, where dogleg severity builds. This study...

In order to propose a practical formula of critical local buckling load based on the direct strength method, background and nature method effective width for calculating ultimate thin-walled members under axial compression are analyzed. Physical significance Pcr, Lis revealed. Selection criteria Lfor two methods is proposed. A L, considering plate-assembly effects, The accuracy proposed verified by comparing its results with exact values computing general beam theory software, GBUTL....

Summary Coiled tubing (CT) integrity is critical for well intervention operations in the field. To monitor and manage integrity, industry has developed a number of computer models over past decades. Among them, low-cycle fatigue (LCF) modeling plays paramount role safeguarding integrity. LCF CT strings dates back to 1980s. Recently, novel algorithms have contributed developments physics-based plasticity. When trips into out well, it goes through bending/straightening cycles under high...

This paper presents the transient response of submerged elastic structures subject to underwater shock waves. Two fundamental effects are investigated, namely, inertial and effects, characterized by two non-dimensional parameters, parameter M K. Case studies provided with physical mathematical interpretations results.