Flange Diameter Research Articles

An experimental study on web-bearing resistance of cold-formed steel sigma-shaped sections with web holes under interior-two-flange loading case

Cold-formed steel (CFS) sigma-shaped sections used as flooring joists and bearers are commonly fabricated with web holes to accommodate building services. These sections featuring web stiffeners and curved lips exhibit lower web-bearing resistance than traditional lipped channel sections. However, the web-bearing resistance of CFS sigma-shaped sections with web holes has not been thoroughly investigated. To address this gap, a detailed experimental investigation was conducted, testing 29 CFS sigma-shaped sections with web holes under an interior-two-flange (ITF) loading case. For comparison, specimens without web holes were also tested. Variables such as hole diameter ratio, hole location, bearing length, and flange condition were examined. A finite element (FE) model was developed and validated against the test results. The results indicated that the web-bearing resistance for specimens with web holes was reduced by 24.0 % on average. To assess the accuracy of existing design specifications, the test results were compared against the design strengths predicted by the American Iron and Steel Institute (AISI) (2016), Australian and New Zealand Standards (AS/NZS) (2018), European Standard (EC3) (2006), and Uzzaman et al. (2012). The comparison revealed that the design strength predicted by Uzzaman et al. (2012) agreed well with the test results.

Off-label use of Lumen-apposing metal stents for treatment of short benign biliary strictures

BackgroundEndoscopic stenting is the mainstay of treatment for benign biliary strictures. There is a not-negligible rate of recurrence and stent migration. Lumen-apposing metal stents (LAMS) have a unique design with short length, large diameter and wide flanges which make them less prone to migration. AimsTo describe the intraluminal use of LAMS to treat short benign biliary strictures. MethodsAll consecutive patients who underwent bi-flanged LAMS placement for benign biliary strictures, in approximately 6 years, were retrospectively included. Primary outcomes were technical and clinical success; secondary outcomes were number of endoscopic procedures, adverse events evaluation and stricture recurrence during follow-up. ResultsSeventy patients (35 male, mean age 67) were enrolled; bilio-enteric anastomotic stricture was the most common etiology. Technical and clinical success were 100 % and 85.7 %, respectively. Patients with post-surgical stricture had a higher success rate than patients with non-surgical stricture or with bilio-enteric anastomotic stricture (90.4 %, 86.3 % and 81.4 %, respectively). Adverse events were 12/70 (17.1 %): stent migration was the most frequent (8/70, 11.4 %). Stricture recurrence was found in 10/54 patients (18.5 %). ConclusionLAMS placement could be safe and effective treatment for short benign biliary strictures in patients in which a significant caliber disproportion between stricture and the duct above was revealed.

Attaining the optimal flange technique for transscleral capsular bag stabilization using iris hooks.

To investigate the flange properties of different iris hooks. Vienna Institute for Research in Ocular Surgery (VIROS), Hanusch Hospital, Vienna, Austria. Laboratory study. The flanging properties of 4 different iris hooks made from polypropylene (PP), elastic polymer (EP), and nylon were investigated with different heating distances and both with and without forceps gripping. The maximum diameter of the flanges was measured, and the shape of the flanges was evaluated. Although both nylon and EP iris hooks had too small flange diameters for intrascleral fixation, PP iris hooks had a sufficient flange diameter (>330 μm) and mushroom-like shape. Furthermore, in PP hooks, heating distance was directly proportional to flange diameter. The findings of this study suggest that only PP iris hooks are suitable for flanged intrascleral fixation, which is off-label, to secure adequate fixation.

SUBSTANTIATION OF INDUCTION HEATING DURING FLANGING OF TUBULAR WORKPIECES BY ROLLING FORMING

Rolling forming (RF) processes are among the most efficient methods of metal forming. The required profile of the workpiece in rolling processes is formed by local deformation with conical or cylindrical rolls using sound technological schemes. When roll forming pipe billets with a ratio of the height of the initial deformed part to the wall thickness of more than 2.5, the flange seating process is made impossible by the loss of billet stability with subsequent fold formation. This phenomenon makes it impossible to produce wide flanges by drawing. To form workpieces with particularly wide flanges, we have developed a flanging method by rolling stamping. The essence of the flanging method is that at the initial stages of rolling, the top of the conical roll is shifted in the direction of the contact patch. At intermediate stages, to prevent the workpiece wall from turning inside out, the top of the roll is shifted in the opposite direction (along the workpiece axis). The main technological constraints are imposed by the insufficient ductility of the billet material, which can cause fracture. To develop the flanging processes in a reasonable manner, we studied the mechanics of outer flange deformation and methods of controlling material flow. The stress-strain state (SSS) of the material was analyzed using the hardness measurement method and the mesh method. The nature of the change in the stress-strain state in the most dangerous zones of the workpiece was determined, depending on the ratio of the flange diameter to the initial workpiece. Based on the experimental results, a mathematical model of the deformation trajectory of material particles of the outer surface of the flange in the coordinates of deformation intensity - an indicator of the stress state - was constructed. To assess the deformability of the material, a damage summation model with a power law approximation of the damage function was used. The model allows us to determine the ultimate fracture dimensions of the flange, as well as the plasticity resource used at intermediate stages. The condition for the suitability of metals for flanging by rolling stamping for engineering calculations is obtained. The necessity of applying induction heating in the processes of culling by rolling stamping is substantiated. This makes it possible to expand the technological capabilities of flanging processes by developing and using induction heating of workpieces, due to an increase in the plasticity characteristics and a decrease in the strength characteristics of metals in the process of deformation.

Mechanical Behavior of Crimping Composite Post Insulator: Experimental and Simulation Study

The composite post insulator composed of a large diameter mandrel and flange pressed by a one-time integral pultrusion has high strength and good toughness and is widely used in the existing flexible converter valve. For constructing the finite element model of the crimped post insulator, most of the flange surface and the mandrel surface are directly connected, making the simulation model’s stiffness deviate from the actual model and the model distortion. Based on this, this study proposes a new finite element simplified model of crimped composite post insulator based on multi-point constraints (MPC), which accurately simulates the crimping area of mandrel and flange in engineering practice. It verifies the model’s reliability through static tests and characteristic vibration tests. The results show that the difference between the finite element simulation and the test results is within 5%. The finite element modeling method based on MPC local constraints is very reliable in applying crimped composite post insulators. Based on the proposed model, the influence of flange height and thickness on the mechanical properties of composite post insulators is further explored. The results show that the influence of flange height on mechanical properties can be ignored when the height of the insulator stiffener (non-press common area) is constant. Within the allowable thickness range of the flange crimping process, the increase in flange thickness will significantly reduce the maximum bending stress of the insulator and increase its safety margin. It provides a good design idea for the design of crimping composite insulators.

Joint Maintenance Strategy Optimization for Railway Bogie Wheelset

A wheelset is one of the most severely worn components of railway bogies. Its health condition has a significant impact on the safety and comfort of railway trains. Moreover, wheelset maintenance costs account for a sizeable part of the railway operating company. Therefore, it is essential to investigate executable maintenance strategies for wheelsets. In this paper, a maintenance strategy that combines periodic inspection and preventive maintenance is proposed. The wheel flange and wheel diameter deterioration models are established by the compound Poisson process based on the cumulative shock from the failure mechanism, and the Weibull distribution is adopted for modeling wheel tread failure probability. The age reduction factor is introduced to describe the maintenance effect. Then, the joint maintenance optimization model is constructed to determine the periodic inspection interval and the reprofiling strategy, with the objective of achieving a minimum maintenance cost rate and with the wheel flange thickness failure as the failure risk constraint. Lastly, a case study is provided, and the results show that, compared with the two conventional maintenance strategies with fixed inspection periods, the maintenance strategy proposed in this paper can reduce the maintenance cost rate by 27.06% and 12.0%, respectively. Moreover, the life span is prolonged by 11.51% and 11.98%, respectively.

Effect of interlock angle and bottom die flange diameter on clinching joint load bearing capacity in cross-tensile loading

Effect of interlock angle and bottom die flange diameter on clinching joint load bearing capacity in cross-tensile loading

Theoretical and Experimental Study on the Effect of Selected Parameters in a New Method of Extrusion with a Movable Sleeve.

This paper presents a new method for forming hollow flanged products. The method involves extrusion with the use of a sleeve moving in the opposite direction to that of the punch. A tube with a constant hole diameter and two different outside diameters, made of aluminum alloy EN AW 6060 was used as a material. Numerical calculations were performed using Deform 2D/3D. Experiments were conducted on the PYE 160SS hydraulic press equipped with a specially designed device in which the punch is driven by the press slide while the moveable sleeve is driven by two hydraulic servomotors. Both numerical simulations and experiments were conducted under cold forming conditions. The aim of this study was to determine the effect of selected parameters (flange diameter, height of the cavity in the moveable sleeve, and the chamfer angle between the regions with different outside diameters on the workpiece and in the moveable sleeve cavity) on the stability of the extrusion process. Results were then used to undertake detailed comparative analyses of underfill, flange heights, and flange flank inclination angles. Findings of the analyses served as a basis for drawing conclusions regarding the effect of the analyzed parameters on the investigated extrusion process.

Investigation of earing defect and thickness distribution in stamp forming of continuous glass fiber reinforced polypropylene composite laminates

When lightweighting studies are examined, thermoplastic matrix composites come to the fore as they have a high specific strength, are recyclable, and can be formed by thermoforming. Some obscurity needs to be overcome for the rapid forming of three-dimensional parts from laminated thermoplastic composites. In this study, deep drawing experiments were carried out to investigate the forming capabilities of continuous glass fiber reinforced polypropylene composite laminates. The parameters of drawing depth, laminate temperature, holding pressure, and punch speed were examined at each three different levels. The effects of these parameters were evaluated on the earing defect and the thickness distribution. It was concluded that the laminate temperature affected both deformations the most. It was determined that all parameters caused a change in flange diameter, but the amount of earing increased with the increase of drawing depth. It was established that inhomogeneous thickness distributions occurred in the part and the highest thickening took place in the curve region.

Experiment on crack resistance of prestressed CFRP tendons-steelreinforced concrete members under eccentric tension

In our country, there are many eccentric tension members, such as steel reinforced concrete truss transfer layer straining beam, low-rise building corner column. For these members, large-scale cracks easily appear during normal use stage. Aiming at these problems, this paper took the light, high-strength and anti-corrosion carbon fiber reinforced polymer composite (CFRP) tendons as the prestressed reinforcement, the prestressed CFRP-steel reinforced concrete structure system was designed by combining CFRP tendons with prestressed steel reinforced concrete, which can effectively restrain the crack. And on this basis, a systematic study on the crack resistance under eccentric tension was carried out. A total of eleven members were designed and fabricated with the prestress level, eccentricity, longitudinal reinforcement diameter and profile flange thickness as the main parameters, and eccentric loading was achieved through the self-developed tension-compression conversion truss system. The results indicate that the crack resistance of the prestressed CFRP tendons-steel/concrete members is greatly strengthened. Compared with the ordinary eccentric members, the cracking loads of the large tension members with prestressed CFRP tendons are increased by 64.8%–102.3%, the cracking loads of the small tension members with prestressed CFRP tendons are increased by 61.7%–117%. The crack resistance of the member is positively related to the prestress level, longitudinal reinforcement diameter and steel flange thickness, and negatively related to the eccentricity. With reference to the combined structural design specification, three positions of the neutral axis of the prestressed CFRP tendons-steel reinforced concrete members during the cracking stage are proposed, and the calculation formula of cracking load is derived. Compared with the test value, the agreement is perfect, which can provide a reference for the application of other composites in the prestressed eccentric tension system.

Magnetically Coupled Electrical Machines for Renewable Energy Applications

Mechanical coupling between the drive and the driven systems in electrical machines poses design challenges. Rigid and flexible couplings have a trade-off between the rotational speed and vibrations, which are associated with misalignment. This paper discusses a procedure for obtaining the dimensions of a pre-designed rigid (flange-type) mechanical coupling system using the finite element-based electromagnetic full-wave simulator element software (FE, ANSYS) for a benchmark torque and proposes a process that replaces a mechanical coupling system by a magnetic coupling system. This paper also elaborates on the comparative performance analysis between magnetic coupling and mechanical coupling. The simulation results of this analysis affirm that adjusting the flange diameter and thickness tune the magnetic coupling system performance similar to that of the mechanical coupling with an added advantage of auto-decoupling when exposed to higher loads. The auto-decoupling property protects the mechanical and electrical system from damage. This research considers the use of COMSOL Multiphysics software for determining the optimum number of magnets to couple the flanges for specified torque and speed, the distance between the flanges, and limits of angular and parallel misalignments. JMAG software is used for the analysis of the dynamic behaviour of the magnetic coupling system and the holding torque characteristics. This manuscript shows that the magnetic coupling technique has promising results in the renewable energy industry, such as wind energy, wave energy and electric vehicles.

SIMULATION AND EXPERIMENTAL INVESTIGATION OF WRINKLE DEFECT IN DEEP DRAWING PROCESS OF CARBON STEEL SPCC SHAPED CYLINDER FLANGE CUP

A Sheet Metal Forming (SMF) process, especially deep drawing, is one of the manufacturing processes that commonly used in the automotive industry. Compared with casting and forging, the SMF process has several advantages, including lesser weight materials and broader variations in shape that can be made. One of the problems in the SMF process is the wrinkling phenomenon, which can cause the size and appearance defects of sheet products. The wrinkle occurs because of the mechanical properties of the material, product geometry, and blank holder force (BHF). Several variations of BHF were applied in these simulations and experiments to eliminate the wrinkle defects of cylinder flange cup test products. The characteristic of the cylinder flange cup is from the cold-rolled coiled steel plate (SPCC) type of material with a thickness of 0.8 and 1.0 mm, the height of 10 mm, the inner diameter of 58 mm, and flange diameter of 76 mm. Simple simulations of the SMF process were carried out by using Solidworks with version 2017, and the experiment was carried out at a 600 kN press with a punch velocity of 40 strokes per minute and blank holder force variations from 0 to 21 kN. The experimental data performed with a single die on a flanged cup cylindrical test material shows that the higher the blank holder force (BHF) number, the smaller the wrinkle defect, and it can be eliminated starting from the BHF number of 15 kN.

A Review of Challenges and Opportunities Associated with Bolted Flange Connections in the Offshore Wind Industry

The use of bolted flange connections in the offshore wind industry has steeply risen in the last few years. This trend is because of failings observed in other modes of joints such as grouted joints, coupled with enormous economic losses associated with such failures. As many aspects of bolted flange connections for the offshore wind industry are yet to be understood in full, the current study undertakes a comprehensive review of the lessons learned about bolted connections from a range of industries such as nuclear, aerospace, and onshore wind for application in offshore wind industry. Subsequently, the collected information could be used to effectively address and investigate ways to improve bolted flange connections in the offshore wind industry. As monopiles constitute an overwhelming majority of foundation types used in the current offshore wind market, this work focusses on large diameter flanges in the primary load path of a wind turbine foundation, such as those typically found at the base of turbine towers, or at monopile to transition piece connections. Finally, a summary of issues associated with flanges as well as bolted connections is provided, and insights are recommended on the direction to be followed to address these concerns.

Application of a Monopole Antenna Probe with an Optimized Flange Diameter for Tdr Soil Moisture Measurement.

Soil volumetric water content (θ) is a parameter describing one of the most important factors conditioning proper plant growth. Monitoring soil moisture is of particular importance in the rational use of water resources for irrigation, especially during periods of water scarcity. This paper presents a method of measuring soil moisture in the vicinity of the plant root system by means of a probe designed to be mounted on a mobile device used for precise plant irrigation. Due to the specific field conditions of the measurement, the design of the probe was proposed as a monopole antenna. Electromagnetic simulations of the probe were carried out with Ansys HFSS software to optimise its dimensions. Then a prototype of the probe was manufactured to conduct laboratory measurements with the use of a vector network analyser (VNA) working in the 20 kHz to 8 GHz frequency range. The VNA analyser was configured to work in the time-domain reflectometry (TDR) mode. From measurements of the time distance between reflections from the probe’s elements it is possible to calculate the bulk dielectric permittivity of the soil surrounding the probe. Next, based on commonly used soil moisture dielectric calibrations one can determine θ of the soil sample. The paper presents simulation results and laboratory tests of an antenna probe. Due to its tough and durable design, this type of probe gives the possibility of easy application in field conditions, which makes it especially suitable for mechanically demanding measurement systems. As the sensitivity zone is comparatively large, this probe is well-suited to measuring soil moisture in the vicinity of the plant root system.

Maintenance intervals for MP-TP bolted connections – A case study

Abstract In offshore windfarms there has recently been an increasing trend in the use of large diameter bolted connections for the connection between the Transition Piece (TP) and the Monopile (MP). The dimensions of such connections cause handling challenges due the size of the bolts, often M72. An cost driver for these connections the need for maintenance: neither the maintenance intervals nor the maintenance scope can be clearly deferred from standards, and industry experience specifically on these large diameter flanges is generally limited. For these offshore installations, maintenance costs and HSE risks can be high due to the difficult accessibility of these bolted connections offshore often in confined spaces. I n addition, maintenance periods should preferably be scheduled in good weather seasons. This paper describes a case study whereby inspection results are used to set the interval to the next inspection with the purpose of minmizing the maintenace costs.

The Study of Geometric Parameters of the Mong Impact on Natural Frequency

The Mong or Tam-tam is sometimes also called Gong, which is a percussion instrument in Thailand. The Mong with boss generates a tone with less shim and a one-key sound. A player has to percuss the Mongs to create a rhythm with a hard rubber mallet. It was originally used for signaling peasant workers in from the fields and telling time in Thai because the Mongs are loud enough to be heard from up to 8 km away. The sound of the Mong is usually generated from the vibration of its own structure. The aims of this analysis were to study the eigen modes and identify the important parameters to generate a natural frequency, in which the boss of the Mong are excited. Finite element analysis and the design of the experiment were used to find the relation of geometric parameters that impact the eigen mode. In this paper, the inertia relief method was used to study the natural frequency of the Mong, while the spectrum analyzer was used to measure the eigen mode. The results showed that the diameter of the horizontal flange and the thickness of the Mong had a significant effect on the eigen natural frequency, which is similar to the Gong. This implies that the thickness and horizontal flange diameter must be increased if wanting to use the Mong with many key tones. The analysis agreed with the actual behavior of the structure of the Gong of Khong Wong Yai.

Axial strength of steel circular hollow section (CHS) X-joints strengthened by flanged larger pipe

In steel design, enhancing the structural joints’ capacity is considered a challenge that faces the designer. This challenge becomes more difficult when it comes to enhancing the capacities of circular hollow section (CHS) joints due to their closed nature that complicates the strengthening process. Recent research related to strengthening T-joints by utilizing two outer hollow ring flanges welded to additional pipe showed that this technique can significantly improve the joints’ strength. In this study, the utilization of this technique is extended for enhancing the axial strength of CHS X-joints. In this regard, a parametric study using finite element models was carried out to investigate the different design aspects that might affect the behavior of strengthened X-joints. The examined parameters included, the ring flange diameter, the stiffening pipe thickness and length for different brace diameter-to-chord diameter ratios and chord diameter to double chord thickness ratio. The results demonstrated that these strengthened X-joints gained significant axial strength that reached up to three times the axial strength of the unstrengthened joints. Guidelines for proper detailing of such strengthening scheme were provided. Finally, an equation that estimates the axial strength of strengthened joints was established based on the achieved results.

Development of Continuous-Flow Total Artificial Heart for Use in Infants

Purpose Heart transplantation in infants and children is an accepted therapy for congenital heart disease, but donor organ availability remains unstable. Mechanical circulatory support is another standard option, but there is a lack of implantable devices due to size and functional range. The purpose of this study was to evaluate in vivo performance of the initial prototype of an infant continuous-flow total artificial heart (I-CFTAH) with one motor and one rotating assembly supported by a hydrodynamic bearing. Methods The I-CFTAH was designed to cover a range of 3 kg infant to 9 kg child (flange diameter - 26.9 mm; length - 44 mm), with nominal design point was matched to a 6 kg child, requiring 1.0 L/min of flow. I-CFTAH was tested using in silico virtual simulation mock loop (VML; MATLAB; MathWorks®) and simulated the hemodynamics as they surge through the system implanted with blood pump (run at 0.5 L/min for 3 kg infant). Lumped-parameter model including systemic/pulmonary circulation, values for impedance, beat rate, and blood volume was used. Results The in silico experiments showed intended performance of scaled down pump (left and right pump flows - 0.5 L/min at 4380 RPM). The difference between the left and right atrial pressures was maintained within ± 5-15 mm Hg. Simulation of I-CFTAH was successfully performed and allowed creating arterial pulsation with this device. Conclusion The present simulation-based approach showed feasibility of I-CFTAH design. The I-CFTAH met the proposed requirements for self-regulation, performance and pulse modulation. Further in vitro validation and in vivo implantation will be necessary to explore this technology in more detail.

Determination of formability considering wrinkling defect in first-pass conventional spinning with linear roller path

Flange wrinkling is one of the common defects that occur in conventional spinning process, severely restricting the improvement of forming quality and formability. How to universally determine the formability dependent on flange wrinkling is a critical issue in conventional spinning process. For this end, such a determining method for the formability in the process is proposed to rationally design the forming parameters to prevent flange wrinkling. The method is as follows: firstly, the maximum circumferential stress during the process is calculated at the outer edge of the flange, where the circumferential stress is considered as the combining result of the shrinkage of flange diameter and the bending of flange; then, the formability is determined by comparing the maximum circumferential stress to critical circumferential stress for wrinkling defect. Based on the method, a formability analytical model considering wrinkling defect in the first-pass conventional spinning process with a linear roller path is established. The formability model is validated by experiments and FE simulations at different spinning conditions. Sequentially, the influences of forming parameters and their interaction on the formability considering wrinkling defect are systematically analyzed. Furthermore, the forming diagrams considering wrinkling defect for the first-pass conventional spinning are established. It is found that the feed ratio has the most significant effect on the formability, followed by the blank thickness, the hardening exponent, the feed ratio-hardening exponent interaction and the feed ratio-sheet blank thickness interaction. The smaller feed ratio and hardening exponent, thicker sheet blank and greater relative sheet blank radius are helpful to increase the formability. The research results could provide a theoretical basis and guidance for the selection of forming parameters in the actual production of the first-pass conventional spinning.

Evaluation of metal plasticity and research on the mechanics of pressure treatment processes under complex loading

A calculating apparatus has been developed to help evaluate the stress-strain state in the plastic forming processes accompanied by a complex loading in which the Bauschinger effect can be manifested. The developed methods are based on the phenomenological approach in which a material map is devised in the form of flow curves, Bauschinger curves, a function j characterizing the hereditary influence of the loading history, plasticity diagrams, and limiting strain surfaces. To evaluate the plasticity resource used, taking into account the non-monotonicity of loading, the relations for determining the main components of the guiding strain-rate tensor were obtained, which made it possible to simplify the calculation of the components of the damage tensor. With the help of the developed calculating apparatus, the applied plasticity resource was evaluated in the process of radial extrusion with the contour sag, which allowed setting the limiting parameters of the shaping. Also, as a result of the research, an increase in the plasticity of the metal was established by selecting rational loading paths in the space of the dimensionless coordinates h, m s , and e u . For example, in the process of radial extrusion with the contour sag due to a change in the nature of the deformation, it was possible to obtain a flange diameter of 44 mm, with the initial diameter of the cylindrical workpiece being 20 mm. The results obtained are important because in most cases the processes of metal pressure treatment are accompanied by non-monotonic deformation