Metal Liner Research Articles

Influence of resin curing cycle on the deformation of filament wound composites by in situ strain monitoring

The residual stress of metal liners wrapped by composite materials has a significant influence on the service performance of rotating parts, such as flywheel rotors and motor jackets. However, the deformation of the liners, the flow of resins, and the temperature variation during the winding process make it difficult to predict and control this residual stress. In this paper, the process-induced strains were monitored online by a strain gauge with the help of a wireless strain meter. The evolution of this strain during the manufacturing process was fully discussed. A rapid curing resin system was used and its curing properties were tested by differential scanning calorimetry. The mechanical properties of the resin matrix and its composite were characterized. The effect of the curing cycle on the evolution of the residual strain was discussed in detail through comparative experiments. The experimental results show that the use of infrared radiation has a significant advantage regarding residual stress accumulation. This advantage is greater when carbon fiber is used than when glass fiber is used. The prestress in composites of glass fiber and carbon fiber increases by 5.9% and 41.7%, respectively, after cooling.

Technology Focus: Acidizing (June 2021)

Hydraulic fracturing technologies propagated from North America outward to other oil- and gas-producing regions in the world. In earlier days, the main technology developments were mostly related to the materials, such as fluids and proppants, and their characterizations. In recent years, more advancements have been made in tools, engineering processes, and analyses. In a cased-hole fracturing treatment, perforating plays a critical role to the success of the job, though it is often overlooked because perforations are visualized as holes with empty tunnel behind the pipe. Any damage is irrelevant because fracturing will simply bypass the damage. In fact, a shaped charge is made of metal liner and case with explosive loaded in between. The metal material is pushed into the formation under extremely high pressure from the detonation of the explosive. Without backflow of reservoir fluid to flush out the debris, the perforation tunnels are very likely plugged. In tight formations, the backflow is not efficient because the permeability is too low and the time scale of the surge is very short. Obtaining information about perforation before pumping the fracture treatment allows the engineers to adjust the job design, adding perforations or other means to deliver a more-desirable outcome for the fracturing treatment. Not all the wells or zones are suitable for hydraulic fracturing. Concerns over the well completion rating, nearby water layers, equipment and water availability, and other environmental and infrastructure constraints can limit the selection of stimulation method. Matrix chemical injection has often been the preferred or sometimes the only option. More-advanced technologies, however, are needed to extend reservoir access beyond the distance of matrix stimulation. Mechanical tunneling tools have been developed in recent years. They can bridge the gap between matrix and fracturing treatment very well. When combined with chemicals, this process can add efficiency in certain carbonate reservoirs. Hydrochloric acid continues to be the most effective and low-cost material for carbonate stimulation. Though exotic chemistries such as chelating agents and organic acids have been promoted for being less corrosive at high temperatures, the cost and dissolving capacity limit their use to large-scale implementation. The ability to inhibit the corrosion tendency of hydrochloric acid can prove to be beneficial in the economics of acidizing. New technologies in corrosion prevention, both in acid stimulation and production processes, should always be beneficial. During the tough year of 2020, and for the foreseeable future, implementation of engineering ingenuity will become more critical to maintain economical energy delivery in our industry. Recommended additional reading at OnePetro: www.onepetro.org. SPE 202369 Novel High-Effective Component for Acidizing Corrosion Inhibitors: Indolizine Derivatives of the Quaternary Quinolinium Salts by Zhen Yang, China University of Petroleum, et al. SPE 203086 First Successful Fishbone Stimulation Completion in Onshore Oil Field in the United Arab Emirates by Fernando Quintero, ADNOC, et al.

Damage quantification in an aluminium-CFRP composite structure using guided wave wavenumber mapping: Comparison of instantaneous and local wavenumber analyses

Composite-overwrapped pressure vessels (COPV) are increasingly used in the transportation industry due to their high strength to mass ratio. Throughout the years, various designs were developed and found their applications. Currently, there are five designs, which can be subdivided into two main categories - with a load-sharing metal liner and with a non-load-sharing plastic liner. The main damage mechanism defining the lifetime of the first type is fatigue of the metal liner, whereas for the second type it is fatigue of the composite overwrap. Nevertheless, one damage type which may drastically reduce the lifetime of COPV is impact-induced damage. Therefore, this barely visible damage needs to be assessed in a non-destructive way to decide whether the pressure vessel can be further used or has to be put out of service. One of the possible methods is based on ultrasonic waves. In this contribution, both conventional ultrasonic testing (UT) by high-frequency bulk waves and wavenumber mapping by low frequency guided waves are used to evaluate impact damage. Wavenumber mapping techniques are first benchmarked on a simulated aluminium panel then applied to experimental measurements acquired on a delaminated aluminium-CFRP composite plate which corresponds to a structure of COPV with a load-sharing metal liner. The analysis of experimental data obtained from measurements of guided waves propagating in an aluminium-CFRP composite plate with impact-induced damage is performed. All approaches show similar performance in terms of quantification of damage size and depths while being applied to numerical data. The approaches used on the experimental data deliver an accurate estimate of the in-plane size of the large delamination at the aluminium-CFRP interface but only a rough estimate of its depth. Moreover, none of the wavenumber mapping techniques used in the study can quantify every delamination between CFRP plies caused by the impact, which is the case for conventional UT. This may be solved by using higher frequencies (shorter wavelengths) or more advanced signal processing techniques. All in all, it can be concluded that imaging of complex impact damage in fibre-reinforced composites based on wavenumber mapping is not straightforward and stays a challenging task.

Simulations on the multi-shell target ignition driven by radiation pulse in Z-pinch dynamic hohlraum* *Project supported by the Science Challenge Project (Grant No. TZ2018001), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant Nos. XDA25051200 and XDA25050200), the National Natural Science Foundation of China (Grant Nos. 11705282 and 11775305), and Hunan Graduate Scientific Research Innovation Project (Grant

We present the first simulation results of a multi-shell target ignition driven by Z-pinch dynamic hohlraum radiation pulse. The radiation pulse is produced with a special Z-pinch dynamic hohlraum configuration, where the hohlraum is composed of a single metal liner, a low-Z plastic foam, and a high-Z metallic foam. The implosion dynamics of a hohlraum and a multi-shell target are investigated separately by the one-dimensional code MULTI-IFE. When the peak drive current is 50 MA, simulations suggest that an x-ray pulse with nearly constant radiation temperature (∼ 310 eV) and a duration about 9 ns can be obtained. A small multi-shell target with a radius of 1.35 mm driven by this radiation pulse is able to achieve volumetric ignition with an energy gain (G) about 6.19, where G is the ratio of the yield to the absorbed radiation. Through this research, we better understand the effects of non-uniformities and hydrodynamics instabilities in Z-pinch dynamic hohlraum.

Adverse reaction to metal debris due to fretting corrosion between the acetabular components of modular dual-mobility constructs in total hip replacement: a systematic review and meta-analysis.

Modular dual-mobility (MDM) constructs can be used to reduce dislocation rates after total hip replacement (THR). However, there are concerns about adverse reaction to metal debris (ARMD) as a result of fretting corrosion between the metal liner and shell. This systematic review reports outcomes following THR using MDM components. It was registered with PROSPERO and conducted in line with Cochrane and PRISMA recommendations.Sixteen articles were included overall, with meta-analysis performed on relevant subsets using a random intercept logistic regression model. Estimated median incidence of ARMD requiring revision surgery within study follow-up period was 0.3% (95% CI 0.1 – 1.8%, from 11 cohort studies containing 1312 cases).Serum metal ion levels were mildly raised in 7.9% of cases, and significantly raised in 1.8%, but there was no correlation with worse clinical hip function scores within studies. Dislocation rate was 0.8%. Revision rate was 3.3%.There are mixed reports of wear on the backside of the metal liner from the acetabular shell and screw heads. Both implant design and component malseating are implicated, but currently it is unclear to what extent each factor is responsible.Studies were poor quality with high risk of confounding, especially from trunnion corrosion. We have made recommendations for further work. In the meantime, surgeons should be aware of the potential risk of ARMD when considering using an MDM prosthesis, and, if selecting one, must ensure proper seating of the liner and screws intraoperatively.Cite this article: EFORT Open Rev 2021;6:343-353. DOI: 10.1302/2058-5241.6.200146

Mechanical Study of Carbon Fiber Reinforced Plastic and Thin-walled Metal Liner in Bi-Material COPV Based on Grid Theory Optimization

Composite over-wrapped pressure vessel (COPV) with ultra-thin metal liner and high strength carbon fiber reinforced plastic (CFRP) structure was widely used in space system. Meanwhile, there are some difficulties in the calculation of COPV stress-strain state related to the elastic-plastic liner and elastic composite. In this paper a novel design theory was proposed for calculating stress distribution in the bi-material COPV and determining the optimal thickness parameters of COPV based on traditional grid theory optimization. This new theory named Parameters Correspondence Relationship Structure Design Method (PCRSDM) can increase the design precision and structure performance factor of COPV compared to traditional grid theory. The correct models of mechanical characteristic between liner and CFRP are established from the view of optimized grid theory, the present theory is useful to develop a theoretical framework to calculate and design the COPV double shells. The COPV stress-strain behavior is also systemically studied by the ANSYS finite element analysis (FEA), the results show good agreement between FEA simulation and PCRSDM calculation. Both FEA and PCRSDM can meet the design requirements of COPV. A complete design, development and qualification testing of a specialized COPV used to satellite propulsion system was successfully conducted to verify the COPV design in terms of PCRSDM and FEA, the result show that PCRSDM is suitable for the design of COPV.

Ageing and air leakage assessment of a nuclear reactor containment mock-up: VERCORS 2nd benchmark

Electricité de France (EDF) operates a large fleet of nuclear reactors and is responsible for demonstrating the safety of facilities, including concrete containment buildings (CCB), which are non-replaceable components. The leak-tightness of CCBs is assessed every 10 years during integrated leak-rate tests (IRLT). For double-wall containments, which have no metallic liners, the leak-tightness is strongly influenced by the degree of cracking of concrete and opening of the cracks, which mostly depends on (a) the prestress decrease due to the delayed strains of concrete and to a lesser extent due to relaxation of tendons steel, and (b) the saturation degree of the Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation concrete wall. Therefore, to optimize the maintenance programs on CCBs, it is important to predict the evolution of drying, creep and shrinkage strains of concrete to be able to correctly assess the pre-stress losses, and finally the air leak-tightness at a structural level during pressure tests or under accidental loadings.To improve our understanding and identify the best modelling practices on this issue, a large experimental program called VERCORS was launched in 2014. VERCORS is a 1/3 mock-up of a 1300 MWe nuclear reactor CCB. It has been widely instrumented, and its concrete thoroughly characterized. A specific attention has been paid to ensure it is consistent with real CBBs features in EDF's nuclear fleet. To complement its internal R&D efforts, EDF decided to associate external partners to this program. One of the means for this is the organization of benchmarks, where all teams are given data and information about the mock-up and are asked to quantitatively predict its behaviour. The present paper reports the organization and findings of the 2nd benchmark which was organized in 2018 and gathered several international teams around the same objective: improve the confidence in the modelling of structural behaviour as well as the leak-tightness of concrete in containment walls under pressure test loading.The benchmark has shown once again that predicting the mechanical and leakage behaviour of containment buildings is a difficult task. The benchmark also yielded interesting information about the possibility to use spatially reduced models to predict the mechanical behaviour and leakage and underlined the fact that more research must be done to better predict the localization of cracks and leakage.Some lessons have been learnt for the next benchmark: EDF will ask to clarify further the calibration methods, will give more data (including drying, creep and shrinkage at different temperatures and moisture measurements in the mock-up), and will help the participants using local leakage data by projecting the raw measurements on a regular grid, so that the local leakage models can be improved.

Pearls: Removing Modular Metal-on-Metal Liners using a Battery-powered Handheld Impaction System.

The number of dislocations following THA is increasing in tandem with the increased number of primary and revision THAs being performed [2, 4]. Dual mobility (DM) articulations can address this complication by allowing the use of larger diameter femoral heads [5], which may contribute to a reduced risk of dislocation associated with DM components. Perhaps for these reasons, the use of DM implants in both primary and revision THA is increasing as well [1, 3, 6-8]. Most DM implants used in the United States employ a modular cobalt chrome liner that engages the acetabular shell with a mated Morse taper. In order to perform acetabular revision on one of these modular components, the modular liner must first be dissociated from the acetabular component. Many manufacturers provide instruments or technique suggestions, but despite these, dissociating a modular DM liner from its shell can be very difficult to do. Design-specific challenges, mechanical and chemical degeneration resulting in cold welding, and corrosion causing abnormal mating of the taper interface can make these liners resistant to removal. We propose a liner removal technique that makes it easier. Techniques to loosen the taper engagement of modular cobalt chrome bearings typically involve introducing mechanical vibration to the rim or face of the acetabular component to disengage the taper using tamps or extractor “plates” [9]. This can be challenging because the force and frequency of vibration required to disengage the liner may be inconsistent and unpredictable. We found that a battery-powered, handheld impaction system (Fig. 1) provides vibration with consistent and sufficient force, frequency, and direction to loosen the modular taper junction of modular DM liners or modular metal liners without damaging the existing well-fixed acetabular shell behind the liner. The battery-powered, handheld impaction system is a standard device that is made by any of the companies that offer drill/reamer power kits.Fig. 1: The battery-powered, handheld impaction system is shown. The system shown here is provided free of charge with the DePuy primary hip system. This particular system offers several modular attachments that can be used for THA. We utilized the bullet tip attachment for this technique.To use this system, we perform a revision approach to the hip of the surgeon’s choosing, and following removal or retraction of the femoral component, we obtain adequate exposure of the acetabular component. We then position the handheld system with the tip of the adaptor on the exposed rim of the acetabular component (Fig. 2). This system typically uses an adapter to attach to the acetabular component and femoral broaches; however, a bullet tip adapter that does not require component attachment is also available. In the example depicted here, we demonstrate the bullet tip stem insertion adaptor provided by the manufacturer. After several (three to five) consistent strikes to the rim of the acetabular component, the liner usually is unseated from the acetabular shell behind it, and its displacement is both visible (Fig. 3) and palpable to the surgeon.Fig. 2: The bullet tip for the impaction system is positioned on the rim of the well-fixed acetabular component after full exposure.Fig. 3: In some cases, the cobalt chrome liner can be visualized to disengage from the acetabular component. In this view, the liner is no longer sitting flush with the rim of the component, indicating disengagement.In modular DM design in this demonstration, the liner frequently seats flush with the rim of the component, making it difficult to grasp the liner for removal from the shell even after it is unseated. Sometimes, though, visual disengagement is not clearly observed; however, in our experience, three to five taps is enough to disengage it. Therefore, in our technique, we would either use a suction device provided by the manufacturer (Fig. 4) or the suction provided by the pulse irrigation system to grasp the liner and remove it from the component (Fig. 5). Once the liner has been removed, the surfaces of the shell and liner can be assessed for corrosion and the revision operation can proceed as planned. We have successfully used this technique to remove the modular DM liner from a number of different manufacturers and modular metal liners from metal-on-metal THA with similar consistency and success.Fig. 4: A suction device is utilized to grasp the unseated liner for removal.Fig. 5: The liner is removed after it is unseated using the suction device.

Experimental and numerical investigation of the cylinder-dome transition region of a pressure vessel

The difference in stiffness between cylindrical and dome regions of a filament wound composite pressure vessel may cause undesirable bending in the cylinder-dome transition region. Because of the bending, strain distribution may be non-uniform in the transition region. Therefore, accurate modeling that captures non-uniform strain distribution in the transition region is crucial for a safe pressure vessel design. In this study, a pressure vessel with a metallic liner was designed. Three identical pressure vessels were manufactured. One of the vessels was cut for detailed geometric investigation. The section of the transition region was investigated using an optical microscope. The termination of each hoop layer and resin pockets under the helical layers were clearly observed at the micro-scale. Also, measurement of layer by layer thickness and fiber volume fraction were performed. Other vessels were pressurized until the burst pressure. Fiber direction strain was measured using strain gauges that were mostly attached to the transition region to capture the non-uniform strain distribution. Two finite element models were created to analyze the transition region. The first finite element model was created with design parameters. The second finite element model was established by considering the findings obtained from the microscopic analysis. Strain distributions obtained from the strain gauges and finite element analyses were compared. In contrast to the first finite element model, strain distribution in the transition region was perfectly matched with the second finite element model. Thus, important aspects of analyzing the transition region of a pressure vessel were addressed for designers.

Prediction of Cylinder Wall Velocity Profiles for ANFO Explosives Combining Thermochemical Calculation, Gurney Model, and Hydro‐Code

AbstractTheoretical prediction of performance indicators of explosives plays an important role in the development of new explosives and explosive formulations. Of particular interest is the possibility to estimate the velocity of metal liner driven by an explosive charge. We present a theoretical model for estimation of metal cylinder wall velocity profiles of non‐ideal ANFO explosives. The model is based on thermochemical calculations using EXPLO5 code, expressing the Gurney energy in terms of JWL equation of state, and using hydro‐code simulation. The Wood‐Kirkwood detonation theory, incorporated in EXPLO5, is applied for calculation of detonation parameters of non‐ideal ANFO explosives. It was found that this approach enables prediction of cylinder wall velocity for ANFO explosives, with the error at V/V0=7 expansion ratio not exceeding 100 m/s.

Fretting Corrosion, Third-Body Polyethylene Damage, and Cup Positioning in Primary vs Revision Dual Mobility Total Hip Arthroplasty

BackgroundDual mobility (DM) articulations were introduced for total hip arthroplasty to reduce the risk of instability for patients who have a high risk of dislocation. The use of DM constructs in both primary and revision total hip arthroplasty has been steadily increasing, leading to concerns regarding potential risks of fretting corrosion, polyethylene wear, metal release, and failure due to component positioning. MethodsA total of 56 retrieved DM constructs were collected. The inner and outer polyethylene liner surfaces were assessed for 7 damage mechanisms, and fretting corrosion was evaluated for the femoral stem, head, and modular liner. Three polyethylene liners with the greatest amounts of embedded debris were examined using scanning electron microscopy. Energy-dispersive X-ray spectroscopy was used to determine the elemental content of the debris. Acetabular cup orientation was analyzed radiographically using the EBRA (Einzel-Bild-Roentgen-Analyse) method. ResultsThe devices were revised most frequently for infection (36%), loosening (21%), and instability/dislocation (18%). The most common polyethylene damage mechanisms were scratching, pitting, burnishing, and embedded debris, and no difference in total damage was found between primary and revision cases. Scanning electron microscopy/energy-dispersive X-ray spectroscopy revealed that debris morphology and composition were consistent with porous titanium coating, resulting from cup loosening or broken screws and augments. A total of 71% and 50% of the constructs were determined to be within the Lewinnek safe zone for inclination and anteversion, respectively. ConclusionThe most notable mechanisms of surface damage were due to third-body debris, especially for the polyethylene surfaces which articulate against cobalt-chromium femoral heads and acetabular liners. Scratching of the femoral head and the metal liner from this debris may support the clinical use of ceramic for DM bearing surfaces in the future.

Design and hydraulic tests of a metal liner composite overwrapped pressure vessels with seamless connection technology

In industries such as aerospace, automobile, and petro-chemical, the composite overwrapped pressure vessels (COPV) have become a popular technique with the features of high stiffness-to-weight ratios and the advantages of leak-before-break. Based on the characteristics of filament winding process, a new technology of weldless connection of metal-lined COPV was proposed. The new technology used filament winding technology instead of welding forming process and designed a sealing groove on skirt length of the head to solve the problems of continuity and sealing between the head and the cylinder body. And an auxiliary forming tool was invented to apply filament winding process on this novel liner structure successfully. Then, the feasibility of the new structure was verified by hydraulic test. And the vessel could withstand the blasting design pressure about 110 MPa. Three damage modes were obtained by macroscopically inspecting of the vessel profile. Finally, based on a Chang-Chang failure criterion and the cohesive model, the finite element model of the novel structure was established by writing a user material subroutine VUMAT. The results show the delamination damage is the main damage mode and the fiber tensile fracture at the transition region of the head and cylinder is the main failure mode of the novel structure.

Intraprosthetic dislocation after a revision hip replacement: a case report

ABSTRACT BACKGROUND: The dual mobility cup (DMC) was initially design in 1974. It was designed to offer additional stability in total hip arthroplasty (THA) and to prevent dislocations. The dissociation of a DMC has been termed an intraprosthetic dislocation (IPD) and is a rare complication. It is defined as separation of the articulation between the polyethylene and head articulation in the DMC. As the utilisation of DMCs in orthopaedic surgery increases, we can expect an increase in this rare complication. We report a case of an IPD in the setting of revision hip arthroplasty in a 72-year-old female. CASE REPORT: The report is on a 72-year-old female patient who underwent revision hip arthroplasty. The articulation utilised was of the dual mobility type. Some eight months later she dislocated her hip. An attempted closed reduction under general anaesthesia with muscle relaxant was unsuccessful. Thereafter she was taken to surgery to perform an open reduction of the hip. Intra-operatively it was found that the dual mobility head had dissociated, with the polyethylene component remaining in the metal liner. A revision of the components was performed. DISCUSSION: We postulate on the mechanisms of dissociation of the dual mobility head. We review the current literature related to IPD and discuss the risk factors associated with this rare complication. CONCLUSION: The diagnosis of IPD is an indication for revision surgery of the DMC. When utilising a DMC, care should be taken to mitigate against the known risk factors for IPD. All dual mobility dislocations should be reduced under general anaesthesia with muscle relaxant Level of evidence: Level 4.. Keywords: intraprosthetic dislocation, dual mobility cup, revision hip arthroplasty

Experimental Evaluation of Using Silica Aerogels as the Thermal Insulator for Combustor Liners

An experimental study was conducted for evaluating the feasibility of using silica aerogel as thermal insulator for combustor liners. Aerogels are a superior material for minimizing heat flux to the metal structure of the combustion liner due to their low thermal conductivity. In this study, a conical natural gas fired swirling-flame combustor was utilized for reproducing the combustion environment. The silica aerogel blanket was attached to the inner side of a perforated combustor liner. Temperature distribution on the outer side of the combustion liner was measured using a calibrated IR camera. To create a protective cooling film over the aerogel surface, cooling air was supplied from the back side of the perforated metal liner and was allowed to penetrate the silica aerogel blanket to be discharged to the combustor. As the combustor was operated at a fixed equivalence ratio of 0.83, cooling air flow rates were varied to evaluate the effectiveness of transpiration cooling on the aerogel blanket as various cooling flow rates. The measured evolution of temperature distribution confirmed thermal equilibriums for every test condition with transpiration cooling. The measured temperature distribution of metal liner demonstrated superior thermal insulation of aerogel blanket under the protection of cooling film with a temperature difference as high as 1580 K between combustion products temperature and the metal liner temperature on the back side. In addition, silica aerogel samples were examined before and after the combustion tests to understand their material degradation exposing to a typical gas turbine combustor environment using high-resolution scanning electron microscope (SEM). Test results suggest multiple degradation mechanisms to the silica aerogel blanket samples from the combustion tests. Improvements can be made to the silica aerogel blankets for a more resilient thermal insulator, for example, by replacing glass fibers in silica aerogels.

A Study of the detonation wave shape inside confined explosive with a metallic copper liner

The behaviour of shock wave inside a shaped charge is so important that the detonation wave nature characterizes (determines) the degree of jet coherency at the liner interface. The detonation wave shape inside the shaped charge depends on the casing thickness, material, the liner material, geometry and the applied wave shaper geometry. In this paper, a series of numerical simulation models were performed to study the incident and reflected waves and to characterize the resulting shock wave front to evaluate its effect on the produced (generated) jet characteristics. The used code was Autodyn 3D based on non-linear dynamic analysis with jetting analysis model. Inert wave shapers (Lead, Aluminium and steel) and active ones (TNT and PETN) behaviour were studied. The liner type used in this study was copper with in which the apex angle of the liner cone was 40°. It was concluded that the wave front shape has an obvious influence on the characteristics of the jet formation and its properties such as mass of jet and velocities of its tip. Also, the bulk sound speed of the liner itself in addition to the collapse characteristics of the liner was discussed in this paper successfully.

Experimental Study of the Strength and Durability of Metal-Composite High-Pressure Tanks

The results of unique experimental studies of the strength and service life of a metal-composite high-pressure tank are presented. The study is aimed at analyzing the fracture mechanisms and evaluating the strength characteristics of the structure. The technique included tests of full-scale samples of the tank for durability under short-term static, long-term static, and cyclic loading with internal pneumatic pressure. The generalized test results and data of visual measurements, instrumental and acoustic-emission control of deformation processes, accumulation of damage, and destruction of full-scale tank samples are presented. The strength and the stiffness of the structure exposed to internal pneumatic pressure are analyzed. The types of limiting states of the tanks are established experimentally. Variation in the stress-strain state of the tank under cyclic and prolonged static loading is considered. The specific features of the destruction mechanism of the metal-composite tank are determined with allowance for the role of the metal liner strain. The calculated and experimental estimates of the energy potential of destruction and the size of the area affected by destruction of the tank are presented. Analysis of the test results show that the tank has high strength and resource characteristics that meet the requirements of the design documentation. The experimental results are in good agreement with the results of the numerical calculations and analysis of the stress-strain state and destruction mechanisms of the metal-composite tank.

Electroless Deposition of Pure Cobalt Film for Realizing Low Resistivity LSI Interconnection

With a scaling trend of LSI interconnection, effective resistivity of Cu/barrier metal interconnect is expected to increase due to increasing electron scattering due to ultrafine dimension smaller than electron mean free path. Therefore, the trend is to substitute Co metal liner for Cu when the line width of LSI interconnect is 10 nm or less. While Chemical Vapor Deposition (CVD) or electrodeposition are discussed as formation method of Co mainly, we introduced electroless deposition (ELD) method. In electroless deposition of Co using Dimethylamine Borane (DMAB), B was incorporated in Co film, and the electric resistivity of the film after heat treatment (400℃ in vacuum, 30 minutes) was 68 µΩ∙cm. In this report, we introduced hydrazine monohydrate as a reducing agent for the purpose of forming ELD pure Co film.ELD Co bath contains cobalt chloride hexahydrate (CoCl2∙6H2O) as metal ion source and hydrazine monohydrate (N2H4∙H2O) as a reducing agent. In addition, some complexing agents were added to prevent Co hydroxide precipitation. Plating bath pH was adjusted to about 12.3 and the CVD-Co film (thickness: 20 nm) on SiO2 and Si was used as substrate for Co deposition. Obtained Co plated film were observed and analyzed by Scanning Electron Microscope (SEM), X-ray Photoelectron Spectroscopy (XPS) and X-Ray Diffraction (XRD). Furthermore, Co plating film was heat-treated at 400℃ in vacuum, and the electrical resistivity of Co film before and after the heat-treatment was measured by four-terminal method.The deposition rate of ELD cobalt bath was about 19 nm/min, and this cobalt film consisted of columnar crystals (Figure 1). If the film surface is rough, it may cause void formation during electroless Co plating in fine via. Regarding the properties of Co film, impurities derived from the reducing agent were not detected from XPS spectral analysis. Co film with few impurities leads to low resistivity because the probability of electron impurity scattering decrease. However, the resistivity of obtained and heat-treated Co film is 53 µΩ∙cm. It is necessary to form the smooth Co film to reduce the electrical resistivity. Figure 1

Estimation of Explosive Energy Output by EXPLO5 Thermochemical Code

Detonation velocity, detonation pressure, and detonation heat are usually used as a measure of explosive's performance. However, they do not answer the question how fast an explosive can accelerate the surrounding metal liner. A semi‐empirical solution to this problem was proposed byR. W. Gurneyin 1943. In this paper we used thermochemical calculations to calculate energy of detonation products along the expansion isentrope and to estimate the Gurney energy and cylinder wall velocity from it. It was found that for the same degree of the products expansion, experimentally determined Gurney energy is systematically less than calculated detonation energy due to the energy losses. At about threefold expansion of the products, the detonation energy matches very well with an experimental Gurney energy.

Fabrication and uniaxial compression mechanical behavior of composite corrugated-core sandwich cylinder with thin-wall metal liner

The strong, stiff and weight efficient composite cylindrical shells with metal liner can withstand axial load, transverse load and higher internal pressure. In this paper, a composite corrugated sandwich cylinder with thin-wall metal liner was fabricated by integrated-solidification. Then, the damage and failure modes of the sandwich cylindrical shells were tested by quasi-static uniaxial compression tests. Finally, an equivalent monocoque shell theory was applied to predict the multi-mode failure by simplifying the sandwich cylinder to a quasi-isotropic cylinder. And the theoretical method could predict the failure modes of the sandwich cylinder within acceptable errors.

Effect of liner offset and inclination on cement retention strength of metal-in-metal acetabular constructs: A biomechanical study.

Cementing metallic liners into well-fixed acetabular shells facilitates utilizing dual-mobility cups in revision total hip arthroplasty without shell replacement. The current biomechanical study investigated the effect of increasing cemented liner (a) inclination; and (b) offset on the cement retention strength measured as the lever-out moment at cement failure. Eighteen metallic liner prototypes were cemented into cluster-hole acetabular shells at variable inclinations (0°, 10°, and 20°) and offsets (0 and 10 mm) relative to the enclosing acetabular shell (6 groups; n = 3 constructs per group). The constructs were connected to a material testing frame, and lever-out failure moments were tested through an established protocol. Failure occurred at the liner-cement interface (18/18). There was no correlation between liner inclination and the lever-out failure moment (r = -0.327, P = .185). Liner offset demonstrated a strong negative correlation to mean lever-out failure moments (r = -0.788, P < .001). There was no significant difference between mean lever-out failure moments at variable liner inclinations, regardless of offset (P = .358). Greater liner offset was associated with diminished mean lever-out failure moments (P < .001). Compared with neutral (0° inclination, 0 mm offset), the maximum inclination and offset group had the lowest mean lever-out failure moment (P = .011). Cemented metal-in-metal constructs are significantly affected by the liner positioning. While a correlation between liner inclination and cement retention strength could not be asserted, cement retention strength is significantly diminished by increased liner offset.