Flange Type Research Articles

Stent misdeployment and factors associated with failure in EUS-guided choledochoduodenostomy: an analysis of the combined datasets from the ELEMENT and DRA-MBO trials.

Stent misdeployment (SMD) is a feared technical challenge of EUS-guided choledochoduodenostomy using a lumen apposing stent (EUS-CDS) that has been poorly characterized. We aim to ascertain the rate of SMD in EUS-CDS for malignant distal biliary obstruction (MDBO) and describe its outcomes while identifying variables associated with its occurrence. In addition, we aim to propose a de novo SMD classification. A post hoc analysis of two RCTs comparing EUS-CDS vs. endoscopic retrograde cholangiopancreatography in MDBO. The main endpoint was the rate of SMD classified as misdeployment of the distal flange (type I), proximal flange (type II), contralateral bile duct wall injury (type III), or double mucosal puncture (type IV). A multivariable analysis was performed to identify variables associated with the odds of SMD and/or technical failure and clinical failure or stent dysfunction. 152 patients were included with a technical success of 93.4%. SMDs occurred in 11 (7.2%) patients (95% CI, 3.1%-11.4%): 8 type I, 1 type II, and 2 type III. Endoscopic salvage was successful in 81.8%. SMDs led to an adverse event (AE) in 4 cases (2 mild and 2 moderate) with an overall AE rate of 2.6% (95% CI, 0.7%-6.6%). On multivariable analysis, an extrahepatic bile duct diameter of ≤ 15 mm was associated with increase odds of SMD and/or technical failure. SMD is relatively common in EUS-CDS and is associated with an extra-hepatic bile duct diameter measuring ≤ 15 mm. The majority of SMDs can be rescued endoscopically with low risk for AE.

CeO2/SWCNT nanocomposite coating: A novel approach for corrosion application

AbstractThe coatings were prepared by blending different concentrations of SWCNTs and CeO2 particles with an epoxy resin by hydrothermal method, which was then applied to the substrate through the doctor blade technique. The mixtures were transferred into a 1‐L capacity autoclave with a teflon‐lined flange type and subjected to hydrothermal treatment at 100°C for 3 h. The surface coatings were applied using a doctor blade. Subsequently, the coated materials were placed in an oven and dried for 12 h at 50°C under vacuum conditions. The samples' structural analysis was examined through x‐ray diffraction (XRD). XRD analysis verified the CeO2/SWCNT composite coating, and Fourier transform infrared spectroscopy (FTIR) was utilized to assess the presence of functional groups. Thermodynamic properties and thermal stability of composite coatings that were modified with SWCNTs and CeO2 particles were studied by thermogravimetric analysis (TGA). The impact of the CeO2/SWCNT composite on the anticorrosion capabilities of the epoxy coating was examined through electrochemical impedance spectroscopy (EIS), Nyquist curve, and Tafel slope characterization. Corrosion tests were conducted on the CeO2/SWCNT composite coatings in a 3.5 wt% sodium chloride (NaCl) solution at 25°C to improve corrosion resistance. The concentration of 0.4 wt% CeO2 was found to be optimal for achieving effective corrosion resistance. The composite coating CNT0.6‐C0.4 exhibited significantly higher Ecorr (−426 V) and lower Icorr (2.96 × 10−6 A cm−2) values compared to samples from the CNT0, CNT0.2, and CNT0.6 groups. The paper presents a viable solution with CeO2/SWCNT composite coating for the engineering application of corrosive‐inhibiting coatings.

Pediatric Custom Tracheostomies: A Ten-Year Experience.

To describe the use of customized and custom tracheostomies at our institution, and to identify trends in patient presentation and tracheostomy design. A retrospective review was conducted for patients at our institution for whom a customized or custom tracheostomy tube was ordered between January 2011 and July 2021. Customized tracheostomy tubes allow for a small selection of alterations to trach design, such as cuff length and flange type. Custom tracheostomies have a unique design created by tracheostomy tube engineers in collaboration with the clinical provider, and are built specifically for a single patient. A total of 235 patients were included, of whom 220 (93%) received customized tracheostomies and 15 custom (7%). The most common indications for customized tracheostomy were tracheal or stomal breakdown on a standard tracheostomy (n = 73, 33%) and ventilation difficulties (n = 61, 27%). The most frequent customization was shaft length (n = 126, 57%). The most common indication for custom tracheostomies was a persistent air leak on a standard or customized trach (n = 9) and the most frequent designs were custom cuffs (n = 8), flanges (n = 4), and anteriorly curved shafts (n = 4). Patients treated with a customized tracheostomy had a 5-year overall survival of 75.3%, compared to 51.4% for custom. These are the first cohorts of pediatric patients with customized and custom tracheostomies to be described. Modifications to tracheostomies, in particular shaft length and cuff design, can address common complications of extended tracheostomy, and may help improve ventilation in the most challenging cases. 4 Laryngoscope, 134:452-458, 2024.

The structural design and earthquake resistance assessment of composite steel–concrete frame structures with welded dissipative fuses

Mitigation of earthquake damage to buildings is a major task in structural engineering. A reliable reinforced concrete structure with composite joints is crucial to create a high-performance structural system. The paper develops and investigates alternative dissipative systems with welded fuses in reinforced concrete structures, particularly, composite steel–concrete frame structures. This paper discusses the findings of an experiment on the mechanical properties of three types of plate flanges with different geometric parameters and power factors under different cyclic loadings. Sample ductility, dissipation, and durability made it clear that increasing the plate’s cross-sectional area leads to increased bending stiffness coefficient and reduced intensity of stiffness degradation during cyclic loading. The tensile strength is twice the yield in the case of sagging, while these values are very close in the case of hogging. Samples with a high power factor have low dissipative properties, thereby contributing to the rapid wear of non-replaceable parts. Plates with a 10 × 100 mm2 cross-section have a sufficiently high resistance and the ability to dissipate the seismic vibration energy. The findings can be used in the design of residential and industrial buildings with reinforced concrete structures with welded fuses. Further research involves studying the effect of other plate parameters on improving the composite structure’s plastic parameters.

Influence of flange geometric configuration and bolt stress on joint integrity during assembly using FEA

The aim of this study is to develop a procedure suitable to determine the maximum bolt pre-stress required for the proper gasket seating in bolted flange connections. The proposed method is valid for all the flange types and assumes that the gasket leakage must be limited so as to not affect the flange joint integrity. A 3D finite element model is used in which elastic–plastic behaviour of the flange material, non-linear gasket material behaviour and non-linear flange–gasket contact are assumed. The final goal of the developed work is to update, using a more realistic perspective, the recommendations given by ASME PCC-1 Appendix-O for bolt pre-stress values when applied to standard dimensional ASME flanges. Additionally, in this work, the effect of the straight portion length of the flange hub at its welded connection with the connected pipe and the fillet radius at the hub-flange transition on the stresses and strains distribution are also addressed.

Residual Stresses in Welded I‐section Members with Flame‐cut Flanges

AbstractThe residual stress distribution influences substantially the stability behavior of steel members. Its shape, directly impacted by the fabrication process, is very different in hot‐rolled and welded members. Among welded members, flame‐cut flanges and hot‐rolled flanges are commonly employed in practice. However, buckling curves of Eurocode 3 are based on experimental tests and numerical simulations performed on welded members having hot‐rolled flanges only and lead to conservative results comparatively to the previous French design standards but also to hot‐rolled members. Investigations are strongly needed to adapt the existing buckling curves to welded members using flame‐cut flanges and a first step is to estimate the residual stress distribution in such members.The results available in the literature dealing with residual stresses measurements in welded members with flame‐cut flanges investigate stocky profiles that can be far from common practice, welded members being preferably slender sections. This paper presents the results of an experimental campaign on residual stresses performed on eight slender welded members varying the flange width and thickness as well as the flange type : hot‐rolled or flame‐cut. The measurements were performed using the sectioning method. A new model for residual stress distribution in welded I‐section members with flame‐cut flanges is then proposed based on these tests results and existing data from the literature.

Shape suitability and mechanical safety of customised hip implants: Three-dimensional printed acetabular cup for hip arthroplasty

BackgroundOwing to an increase in the number of hip arthroplasty surgeries, the number of implant replacement surgeries is increasing rapidly as well. This necessitates the study of hip joint conditions. Therefore, Paprosky defined a classification system to indicate the degree of damage to the hip joint. In this study, a customised hip implant suitable for Paprosky classification Type ⅡC and over was designed. The shape, suitability, and mechanical safety of the worst-case model for the implant were evaluated. Materials and methodsTo identify the implant size depending on states over Type ⅡC acetabulum bone loss, a size range was selected and a customised implant was designed according to the computed tomography data within the size range. The implant was designed for the flange, hook, and flattened model types. The worst-case selection test was conducted using finite element analysis. The von Mises stresses of the flange, hook, and flattened models were found as 76.223, 136.99, and 80.791 MPa, respectively. Therefore, the hook-type model was selected as the worst case for the mechanical performance test. ResultsA bending test was conducted on the hook-type model without fracture and failure at 5344.56 N. The proposed customised implant was found suitable for Type ⅢA acetabulum bone loss, whereas the shape suitability and mechanical safety were verified for the worst case. ConclusionThe shape of a customised implant suitable for Paprosky ⅢA type was designed. The shape suitability and mechanical safety were evaluated using finite element method analysis and bending tests. Clinical validation is required through subsequent clinical evaluation.

Axial tensile test and design method of special-shaped rigid flange

Unlike the conventional flange with 90°-connecting angle, the new type of special-shaped rigid flange adopting non-90°-connecting angle can effectively reduce the joint region dimensions of steel tube connection in some conditions. Three special-shaped rigid flanges that adopt 45°, 60° and 75°-connecting angles were designed and tested under axial tensile load to investigate the mechanical characteristics and design method. The slip and open deformations occurred between two flange plates under axial tensile load, and the connecting bolts bore non-uniform tensile and shear forces along the bolt elliptical circle, which increase from the short axis to the long axis of elliptical flange plate. In addition, the nonlinear finite element model, whose accuracy was validated by the test results, were built to further inspect the bearing capacity and force-transfer mechanism. The results reveal that the bolt tensile forces are larger than the design values, and the corresponding modified factor was proposed. The stress developments of different fan-shaped sectors were analyzed, and the sectors located on the short axis are suggested to be selected for strength design of flange plate. The stiffener of these sectors has larger load allocation factor, and should be chosen for the strength design of stiffener weld lines. Lastly, the design method of special-shaped rigid flange under axial tensile load was provided, in which the combined tensile and shear forces should be considered for the connecting bolts and weld lines.

Research on vacuum properties of CuCrZr UHV flanges for the Hefei Advanced Light Facility

Hefei Advanced Light Facility (HALF), one of the Diffraction-Limited Storage Rings (DLSR), requires low-impedance flanges to be welded with Oxygen-free with Ag (OFS) vacuum chamber. In this paper, CuCrZr alloy as flange material and spring energized metal C-ring sealing structure are proposed. Two types of CuCrZr flanges have been designed, which are chain clamp and bolted flange, respectively. Chain clamp flanges are planed for compact areas, due to its small axial dimension. Bolted flanges with better positioning ability are designed to place in sections without space limitation. A series of leak rate and outgassing rate measurements were performed, and force and finite element analyses were carried out. Leak rates of both two flanges are lower than 5×10−13Pam3s−1 after 10 times seal-changing tests and 15 times same-seal bakeout cycles. Required fastening torques of chain clamp and bolted flange are 5–7 N m and 3–5 N m, respectively, in order to achieve sealing. The outgassing rate of CuCrZr is about an order of magnitude less than that of stainless steel after bakeout to 250 °C. The simulation results indicate that stress on the CuCrZr flange is far lower than metal C-ring due to the large deformation of the seal.

The MODIFICATION OF THE DRIVE SYSTEM IN AUTOMATICAL AMMUNITION CLADDING DETROYER

The era of the Industrial Revolution 4.0 military power became one of the important elements because technological developments have changed the entire order of military strategy. One of them is the development of military equipment technology part of weaponry. As is known, often Indonesia army soldiers conduct shooting exercises to defend the Nation and the Unitary State of the Indonesian People (NKRI). With the shooting training there is a lot of waste from bullet cladding. Bullet cladding or patrun is an object that is a container that wraps around a bullet projectile and consists of propellant (gunpowder), rim, and primer. Bullets/munitions after firing can still be recycled back into active munitions. In accordance with the purpose of this study, researchers modified a cladding machine in order toimprove the performance of thetool effectively than before. The research methods used are a combination of experimental and empirical manual calculations to determine the relevant results. The result destruction can cut 3 grains of cladding even more in everyone round of the cutting blade, so this study modified the transmission system, fixed clutch, shaft, straight gear. The transmission uses a1:60 wpa gearbox ratio, with an electric motor drive power of 1.5 kW/ 2 HP, 1450 r / min, using a flange type clutch.

A CFD Study of a Flanged Shrouded Wind Turbine: Effects of Various Flange Surface Types on Output Power

There is a global trend to optimize energy harvesting from all energy resources including renewable energy. In this study, the focus is on improving the surface of flanges in flanged shrouded wind turbines to obtain more efficient systems. A CFD approach is utilized for this purpose. All models are identical in the entrance diameter, exit diameter, length of the diffuser, and the height of the flange, but each model is of a different flange surface type. Different surfaces are studied, including a simple surface and some furrowed surfaces. The validation reports that there is a strong correlation between the present study's outcomes and that of previously experimental results. The results show that the models with furrowed surface flange type lead to an increase in the wind velocity when approaching the wind turbine blades. This leads to about 5-7% more output power. Also, the results indicate that the maximum velocity occurs at about 5cm after the shroud entrance. Consequently, it is suggested that the wind turbine should be installed at that location inside the shroud, to obtain the optimum energy harvest.

Impact of concrete strength on seismic behavior of T-shaped double-skin composite walls

This study investigates the seismic performance of T-shaped double-skin composite walls (DSCWs), which are comprised of double-skin composite flange and web walls and concrete filled steel tubular (CFST) boundary elements, through experimental tests. Six T-shaped DSCW specimens, which are categorized into three groups, according to flange width and type of mechanical connectors (shear studs/tie bars), are tested under combined axial compressive loads and lateral cyclic loads. The DSCWs fail in a ductile flexural mode with similar damage patterns, characterized by buckling of steel tubes and faceplates, concrete crushing, and fracture of steel tubes at the wall base, and exhibit asymmetric hysteresis behaviors, with higher stiffness and strength but lower deformation capacities when the flange walls are under tension. Special focus should be placed on the design of CFST boundary element connected to the web wall, whose compressive failure triggers the loss of load carrying capacity of the specimens. The comparisons between the behaviors of two specimens in each group, which are infilled with high strength (C70) and normal strength concrete (C30) respectively, suggest that employment of high strength concrete improves the seismic behavior of T-shaped DSCW significantly regardless of the flange wall width when shear studs are used. Tie bars may impair the seismic behaviors of DSCWs by inducing premature local buckling of perforated steel faceplates. Numerical studies are conducted using detailed finite element models to investigate the buckling behaviors of steel faceplates which are connected to infilled concrete by tie bars and shear studs. The simulation results reveal that the former buckles earlier than the latter due to smaller critical stress. The slenderness ratio limits to prevent local buckling prior to yielding of steel faceplates are also suggested when these two types of mechanical connectors are used.

Manufacturing and development of a bolted GFRP flange joint for oil and gas applications

The goal of this experimental study is to manufacture a bolted GFRP flange connection for composite pipes with high strength and performance. A mould was designed and manufactured, which ensures the quality of the composite materials and controls its surface grade. Based on the ASME Boiler and Pressure Vessel Code, Section X, this GFRP flange was fabricated using biaxial glass fibre braid and polyester resin in a vacuum infusion process. In addition, many experiments were carried out using another mould made of glass to solve process-related issues. Moreover, an investigation was conducted to compare the drilling of the GFRP flange using two types of tools; an Erbauer diamond tile drill bit and a Brad & Spur K10 drill. Six GFRP flanges were manufactured to reach the final product with acceptable quality and performance. The flange was adhesively bonded to a composite pipe after chamfering the end of the pipe. Another type of commercially-available composite flange was used to close the other end of the pipe. Finally, blind flanges were used to close both ends, making the pressure vessel that will be tested under the range of the bolt load and internal pressure.

RESEARCH OF PUNCHING PROCESSES BY PACKING WITH USE OF SURFACE HEATING OF PREPARATIONS

Despite the fact that stamping processes have been around for a relatively long time and have significant advantages compared to traditional approaches, as well as high technical and economic indicators, this process is not widespread. The machine-building industry needs mass production and use of sophisticated parts of various designs. The need of Ukraine for the details of such a design varies significantly and can reach tens of millions of pieces. The need for ring blanks of type flanges (gear) of the total amount is more than 50% [1]. According to foreign enterprises, when cutting, the material utilization ratio is 40-50%, and when using stamping, it is pumped through using surface heating of workpieces - 75-80% [5]. If we take into account the use of energy for the production of steel and its processing per unit weight of the finished part, then it is 70–84 MJ / kg when machined, and 41–49 MJ / kg for plastic deformation. To improve the ductility and deformability of the material, it is advisable to use induction plants for heating carbon steel preforms before pressure treatment. Two types of fundamentally different heating options are used: pass-through, when the workpiece warms up to its entire thickness with a temperature difference between the surface and the core of 50-100 °, and surface, when you need to heat only a relatively small layer of metal to a certain depth. Before stamping, wetting requires the use of surface induction heating, which provides greater surface plasticity of the workpiece material without changing its structure [3]. In this regard, surface and end-to-end inductive heating installations are widely used in stamping processes for wetting. The absence of theoretically justified parameters of the regime leads to the use in practice of induction heating of systems with unsuccessful design solutions and relatively low technical and economic indicators. Thus, there is a need for relevant research aimed at determining the rational parameters of the heating mode, providing on this basis effective processing of workpieces.

Study on characteristics of fatigue strength of ARALL composite in constructive elements

Due to Fatigue Testing fatigue life of specimens made of various materials and with various flange types was estimated. Specimens with dish-shaped and ring-shape flanges were tested. Specimens were made of aluminum alloy D16chATV sheets (thickness 1.2 mm) and of ARALL with a thickness of 1.2 mm based on aluminum layers of 0.5 mm thickness. Specimens were tested under 3 levels of cyclic stress: σmax=120, 100, 80 MPa with minimum stress of σmin=20 MPa. Some of ARALL specimens were tested only under σmax=100 MPa stress level. Under each stress level were tested 5 – 6 specimens. According to the results of all specimen tests the authors plotted plotted fatigue curves. Using the Finite Element Method the stress state of specimens during cyclic stress tests was analyzed. Calculations of fatigue life of specimens were made on the basis of the offered method. Full-element and numerical experiments revealed that fatigue resistance of monolithic alloy specimens with dish-shaped flange under all stress levels is higher than of specimens with a ring-shaped flange. ARALL specimens with dish-shaped and ring-shaped flanges both according to test results have a higher fatigue resistance than monolithic alloy specimens.

The metal gasket sealing performance of bolted flanged with fem analysis

There is a wide variation of flange style and configuration, but only four types of facing are widely used, which are raised face, flat face, ring joint facing and lap joint flange. Corrugated metal gaskets 400MPa-mode has better performance than gaskets 0Mpa-mode for flat face flange type. In this study we investigated the performance of corrugated metal gasket 400MPa-mode for three types of flange facing which are raised face, flat face and combination raised-flat face. The finite element method employed to analysis the effect of different types of flange on contact width and contact stress in relation with axial force of corrugated metal gasket. The result shows corrugated metal gasket 400MPa-mode give good performance for all type of flange face.

Numerical Simulation of Damage Accumulation in a Composite Flange with a Delamination Defect

In this work, a numerical model for predicting the residual life of structures made of polymer composite materials using a structural-phenomenological model is proposed. To estimate the residual life of PCM structures under cyclic loading, it is proposed to use the approach of explicit describing the process of adhesive layers’ destruction. The model is implemented in the APDL language in ANSYS Mechanical engineering complex. The model and the program testing was carried out on a flange type construction with a defect. A comparison of numerical experiments was made for flanges with and without the defect.

Influence of Flange on Seismic Performance of 1,100-kV Ultra-High Voltage Transformer Bushing

Failures of the metal flange were observed in transformer bushings in previous earthquakes. In order to evaluate the influence of the flange on the seismic responses of 1,100-kV ultra-high voltage (UHV) bushing, two types of flanges were selected, which used different materials and layouts. The finite element (FE) and theoretical analyses were first carried out. The results indicate that there is an out-of-plane rocking effect at the flange bottom plate, and the flange will be damaged if the stiffeners are improperly designed. Then two identical bushings using different flanges were tested on the shaking table. The bottom plate of the cast aluminum flange cracked along the stiffeners accompanied by oil leakage. However, the UHV bushing with stainless steel flange survived in the test. It is concluded that the properly designed flange could improve seismic performance of UHV transformer bushings.

Experimental research on dynamic tensile behavior of full-scale weld-necked flange joints used in transmission steel tubular towers

A new type of weld-necked flange (WF) joint is presented in this paper. The flange neck of the new WF joint adopts an inner-slope section with a taper angle ranged from 20° to 25°, with the flange plate being thicker than the traditional WF joint. Compared to the traditional WF joint, the bolt cluster circle of the new WF joint is reduced relative to the steel tube wall. As a result, the effect of tensile load eccentricity on the steel bolts is significantly reduced. A series of dynamic tensile tests is conducted on the new WF joint. The stiffness of the flange plate is of importance to reduce the prying force for the new WF joint. The thickness of the flange plate, which is an important parameter for the new WF joint, is investigated to study the effects on the new WF joint’s dynamic behavior. Meanwhile, the finite element model of the new WF joint is developed to study their dynamic tensile behavior. The finite element model is verified by experimental results and proved to be precise and reliable. Base on the finite element analysis, the dynamic stress distribution and contact pressure at typical locations of the new WF joints are better revealed. Afterwards, a simplified design model for the new WF joints under tensile force is proposed, which can meet the safety and economic requirements in practical engineering projects. Furthermore, the design model can provide valuable reference for the design of the new WF joints.

Thermo-mechanical performance of automotive disc brakes

The kinetic energy of the vehicle is converted into mechanical energy while braking which leads to heat dissipation and temperature rise of the disc and the disc-pads. The aim of this investigation was to study the rise in temperature of an automotive disc brake at the time of braking and its effect on disc durability using finite element method. Application of a specified braking torque on the rotor led to generation of heat flux. The heat flux generated and the heat transfer coefficient taken into consideration were numerically analyzed, which were then used to calculate the rotor rigidity, maximum temperature rise on the disc rotor. The rotor was further loaded with thermo-mechanical cyclic stresses which were used to analyze the durability and fatigue factor of safety of disc. The influence of variations in disc rotor geometry i.e. holes and airfoil ventsin comparison to a simple flange type disc were studied and their effect on maximum temperature rise and disc durability has been investigated by modeling and conducting FEM techniques in Solid works and ANSYS respectively.