Flange Size Research Articles

Dislocation force of scleral flange-fixated intraocular lens haptics

PurposeTo measure the dislocation forces in relation to haptic material, flange size and needle used.SettingHanusch Hospital, Vienna, Austria.DesignLaboratory Investigation.Methods, main outcome measures30 G (gauge) thin wall and 27 G standard needles were used for a 2 mm tangential scleral tunnel in combination with different PVDF (polyvinylidene fluoride) and PMMA (polymethylmethacrylate haptics). Flanges were created by heating 1 mm of the haptic end, non-forceps assisted in PVDF and forceps assisted in PMMA haptics. The dislocation force was measured in non-preserved cadaver sclera using a tensiometer device.ResultsPVDF flanges achieved were of a mushroom-like shape and PMMA flanges were of a conic shape. For 30 G needle tunnels the dislocation forces for PVDF and PMMA haptic flanges were 1.58 ± 0.68 N (n = 10) and 0.70 ± 0.14 N (n = 9) (p = 0.003) respectively. For 27 G needle tunnels the dislocation forces for PVDF and PMMA haptic flanges were 0.31 ± 0.35 N (n = 3) and 0.0 N (n = 4), respectively. The flange size correlated with the occurring dislocation force in experiments with 30 G needle tunnels (r = 0.92), when flanges were bigger than 384 micrometres.ConclusionsThe highest dislocation forces were found for PVDF haptic flanges and their characteristic mushroom-like shape for 30 G thin wall needle scleral tunnels. Forceps assisted flange creation in PMMA haptics did not compensate the disadvantage of PMMA haptics with their characteristic conic shape flange.

Research and Analysis of Leakage Detection of Chemical Equipment Based on Infrared Technology

This paper introduces the application of infrared thermal imaging detection technology in LDAR detection, then the various components of the chemical equipment are detected by infrared photography, and the leakage situation is analyzed. The following conclusions are drawn: The bolt preload of the flange connection is not balanced, which is easy to cause partial leakage. A large number of test data show that the larger the flange size, the greater the leakage. Because of the lack of effective non-destructive testing methods for nozzle fillet welds, infrared testing technology can be adopted for important equipment in use, which can find penetrating buried defects and reduce the risk of equipment use.

Lateral-torsional buckling resistance of corrugated web girders

AbstractThere is currently no accurate calculation procedure for determining the lateral-torsional buckling resistance of trapezoidally corrugated web girders. Therefore, a detailed investigation is performed in the frame of an experimental and numerical research program at the Department of Structural Engineering of the Budapest University of Technology and Economics. Based on the previous experimental results, a numerical model is developed to be used to determine the lateral-torsional buckling resistance by using deterministic method. The effect of flange size, corrugation geometry and boundary conditions are investigated. An improved design method is developed for the determination of the lateral-torsional buckling resistance of trapezoidally corrugated web girders.

Ultra low cycle fatigue behavior of Q690 high-strength steel welded T-stub joints: Experiments and fracture prediction analysis

The paper presented an experimental and numerical investigation of the ultra low cycle fatigue behavior of high-strength steel welded T-stub joints. The normal and funnel T-stub joints in Q690 high-strength steel were tested under monotonic tensile loading and ultra low cyclic loading. The cyclic response of normal T-stub joints varying from bolt diameter, flange size and weld form were studied. It is found that fracture mode of the T-stub joints is basically the same under tensile loading and cyclic loading, i.e., cracking behavior occurs at the weld toe of the flange and tensile-shear failure is observed. The different configuration parameters of normal T-stub joints in the study show no significant influence on the fatigue life of the joints. Comparing the ultra low cycle fatigue results between normal and funnel T-stub joints indicates that the funnel T-stub joints have better energy dissipation capacity. In addition, the ultra low cycle fatigue performance of Q690 steel and ER80-G weld metal under various stress states were analyzed and discussed. In order to numerically generate the overall fracture behavior of the T-stub joins, the Lode parameter enhanced cyclic void growth model was adopted in the numerical simulation and the model parameters were calibrated according to the test results of Q690 steel and weld metal. Comparison with the experimental monotonic and cyclic tests of welded T-stub joints shows that the Lode parameter enhanced cyclic void growth model can provide accurate predictions of the ultra low cycle fatigue of the joints.

Experimental Study of the Charring of I-Joists and Recession of Combustible Insulation in Light Timber Frame Assemblies with Comparison to Eurocode 5

Design models are commonly used in fire safety design of light timber frame assemblies. Parameters for use in the models are available for rectangular members with mineral wool, wood fibre or cellulose insulation and for assemblies with I-joists and mineral wool. For assemblies where I-joists and combustible insulations are combined, design parameters are missing. Five fire experiments with two I-joist types and four combustible insulation products have been conducted. The aim was to study charring of I-joist flanges and recession rates of combustible insulations and in addition, to compare their behaviour to the new and existing models of Eurocode 5. Charring rates for the flanges were 0.40–0.76 mm/min and 0.54–1.72 mm/min for the protected and post-protected phase, respectively. Rates decreased with increasing flange size. Charring rates for flanges of solid wood and LVL were comparable. The results show that lateral charring of I-joist flanges can be significant in the protected phase. The tested insulation products showed a lower recession rate than values reported for glass wool insulation, with a more pronounced difference for wood fibre and cellulose insulations. The low recession rates compared to previously reported generic values can possibly be explained by better product-specific properties, negligible shrinking and slightly different test set-up. The insulation stayed well in place after gypsum board fall-off and best-practice for keeping the insulation in place is given. The results, completed with future loaded full-scale tests, can give basis for further development of design models for assemblies with I-joists and combustible insulations.

An Overview of Angle Deviations of Fiber-Reinforced Polymer Composite Angular Laminates.

After manufacturing, fiber-reinforced polymer composite laminates may have residual stresses, resulting in warpage in flat structures and angle changes in angular sections. These shape distortions may cause fitting mismatch problems under high-level assembly, and extra efforts to fix these problems may be needed. The present paper only makes an overview of the angle deviation of angular composite laminates made of either thermoset matrix with autoclave curing or thermoplastic matrix with thermoforming. Depending on the positive or negative angle deviation, spring-back or spring-in behavior is observed. There are many parameters, including intrinsic and extrinsic parameters, that could affect the angle deviation. In the first part of this review paper, experimental results concerning the effects of the part angle, part thickness, lay-up sequence, corner angle, flange size, tool material, tool surface, and cure cycle are summarized. Spring-in angles are generally obtained in this part. In the second part, several prediction methods, such as simple equations and finite element methods, are compared to indicate the considered parameters. Some have good agreement and some have larger errors. The crucial differences may be dependent on the micromechanical theories and the input properties of the composite and the constituents.

Validation study of in situ sound absorption measurement

An in situ acoustic tube measurement is a non-destructive way to measure the sound absorption coefficient of a material. This method is practical for obtaining sound absorption in cases where it is not straightforward to sample specimens in applications such as automobile interiors, room walls, ceilings, or carpeted floors. However, the in-situ method's limitations lie in measurement errors due to the sound energy leakage through the open boundaries within the materials. In addition, it is not straightforward to provide a general correction factor compared to the standard in-tube method because the errors depend on various factors such as material characteristics, material flow resistance, installation conditions, pipe flange size, etc. The aim here is to provide practical guidelines for reducing in-situ error by analyzing and comparing that procedure with the standard in-tube method. Here, in-tube and in-situ methods were used to measure and they were then analyzed by creating FEM-based acoustic tube and poro-elastic material models. The effect of material flow resistivity and flange thickness were investigated and reported.

Underwater oscillations of rigid plates with H-shaped cross sections: An experimental study to explore their flow physics

In this work, we present a comprehensive experimental study on the problem of harmonic oscillations of rigid plates with H-shaped cross sections submerged in a quiescent, Newtonian, incompressible, viscous fluid environment. Motivated by recent results on the minimization of hydrodynamic damping for transversely oscillating flat plates, we conduct a detailed qualitative and quantitative experimental investigation of the flow physics created by the presence of the flanges, that is, the vertical segments in the plate cross section. Specifically, the main goal is to elucidate the effect of flange size on various aspects of fluid–structure interaction, by primarily investigating the dynamics of vortex shedding and convection. We perform particle image velocimetry experiments over a broad range of oscillation amplitudes, frequencies, and flange size-to-width ratios by leveraging the identification of pathlines, vortex shedding and dynamics, distinctive hydrodynamic regimes, and steady streaming. The fundamental contributions of this work include novel hydrodynamic regime phase diagrams demonstrating the effect of flange ratio on regime transitions, and in the investigation of their relation to qualitatively distinct patterns of vortex–vortex and vortex–structure interactions. Finally, we discuss steady streaming, identifying primary, and secondary structures as a function of the governing parameters.

Attaining optimal flange size with 5-0 and 6-0 polypropylene sutures for scleral fixation.

A technique for achieving an optimal flange size with 5-0 polypropylene and 6-0 polypropylene used for flanged intrascleral intraocular lens fixation is described. Flange size in polypropylene sutures is dependent on heating length and independent of forceps grip during heating. It was identified that heating of 1 mm created the optimal flange size for a 5-0 polypropylene suture when used for a 27-gauge needle scleral tunnel and for a 6-0 polypropylene suture when used for a 30-gauge needle scleral tunnel. Alternatively, 2 mm heating of a 6-0 polypropylene suture fits well for a 27-gauge needle tunnel. Even gentle forceps grip caused flattening of the polypropylene sutures but did not influence shaping and sizing of the flange.

Flexural behavior of prestressed concrete-filled steel tubular flange beams

This research presents a numerical and analytical investigation on the structural characteristics of concrete-filled steel tubular flange beams (CFSTFBs) prestressed using steel strands under bending. CFSTFBs are found to benefit from higher flexural and shear strength compared to those of I-section beams with flat flanges. The geometrical configurations of these sections provide them with higher web local buckling resistance due to a larger flange depth-to-width ratio. A large number of existing structures, constructed with steel–concrete composite beams, need to be retrofitted due to many factors such as loss of strength as a result of service loads and environmental conditions. A potentially economical and feasible approach to strengthening these beams is upgrading them using steel prestressing strands. The finite element (FE) approach was utilized to develop a three-dimensional numerical model considering both material and geometrical nonlinearity. Accordingly, the effects of concrete strength, tubular flange shape and dimension, steel yield stress, and quantity and eccentricity of strands were included in the analysis. A simplified model, on the basis of the plastic stress distribution method (PSDM), was used to estimate the ultimate moment capacity. In order to visualize the influence of steel and concrete strength and tubular flange size on the moment capacity of CFSTFBs, several artificial intelligence (AI) algorithms were employed and a partial dependence analysis was also conducted accordingly. The ultimate capacities obtained by analytical and FE models, considering the effect of confinement, were verified by comparing the predictions with the results from experimental studies. Both analytical and FE results indicated that the prestressing strands are significantly capable of enhancing the stiffness and strength of CFSTFBs under flexural loading. It was demonstrated that the tube geometric properties can significantly control the overall performance of prestressed CFSTFBs. The results also indicated a negligible effect of the concrete compressive strength.

Improved technique for radar absorbing coatings characterization with rectangular waveguide and numerical modeling

<span>For materials characterization, several methods have been developed. Most of them need a sample to be machined prior to testing process. Hence, they are destructive and cannot be used for in-situ radar absorbing coatings testing. This requires employing a suitable measurement technique to extract their electromagnetic properties quickly and accurately. In this paper, the swept frequency of probe reflection technique is proposed for broadband nondestructive radar absorbing coatings characterization using finite flange open-ended rectangular waveguide. The technique is based on the fact that the frequency of measurement is an independent variable of probe’s reflection coefficient by which its data set of selected frequency points can be directly measured in one step by varying the frequency. Finite-difference time-domain (FDTD) method was adopted to calculate probe reflection coefficients at different test conditions. Simple interpolation approximation was employed since they are frequency dependent parameters. Error analysis was numerically performed to evaluate the influences of both flange size and coated material thickness on the accuracy of the measurements, which are carried out on several samples of radar absorbing coatings at X-band to verify the proposed technique. Comparing with the existing methods, the proposed technique simplifies and speeds up measurement process and improves its repeatability and accuracy.</span>

Experimental study on the hysteresis behavior of L-shaped double-skin composite wall with concrete-filled steel tubes

In this paper, the seismic behavior of L-shaped double-skin composite wall (DSCW) with concrete-filled steel tubes were investigated. The influence of different parameters, i.e., axial compression ratio, shear span-to-depth ratio, corrugation size, corrugated arrangement, flange size and CFST side column were discussed based on cyclic tests. The hysteresis behavior of DSCW specimens in terms of hysteresis curves, skeleton curves and rigidity deterioration were analyzed. The failure mechanism, as well as the composite effect between each component was also compared based on the strain analysis. It was concluded that the L-shaped DSCW has favorable seismic ductility and toughness with the maximum lateral drift angle of 3%. With the increase of axial compression ratio, the peak load of DSCW specimens increased while the post-peak ductility decreased. By contrast, the peak load of DSCW specimens decreased with the increase of shear span-to-depth ratio. More corrugations are effective to increase the seismic behavior of L-shaped DSCW and it was recommended that the corrugations should be arranged vertically. The flange size has limited influence on the failure processes and carrying capacity of DSCW specimens, while the stress distribution was highly dependent on the flange design of DSCW. The application of concrete-filled steel tubes (CFST) side column is effective to increase the seismic behavior of DSCW and also has significant influence on the composite effect between each component.

The induction heating process modelling of the waveguide paths’ flanges

The article presents mathematical heating model the flange is in process induction soldering of waveguides paths. In the quality of object of research stands out creation process all-in-one connections based on induction heating, or more precisely, patterns distributions energy over time by default flange size waveguide the route. Goal creating a model consists of in the upgrade process quality of management technological equipment process production facilities antenna-feeder devices based on the induction soldering technology. Developed by models can be used for adaptive management technological equipment process induction system soldering when production waveguide paths assemblies.

Multilayer Structure Technique for Improving Determination of Electromagnetic Properties of Radar Absorbers Based on Two-Layer Method and Flanged Rectangular Waveguide Probe

This paper presents further development of utilization of two-layer method to perform nondestructive electromagnetic properties determination of planar radar absorbers using flanged open-ended rectangular waveguide probe. A multilayer structure of three layers was proposed to improve the measured results of these parameters obtained using two-layer method. These layers were arranged such that the test material is sandwiched between two known low loss materials to provide the needed two independent reflection coefficients necessary to extract them at different conditions of testing. The proposed structure was aimed to decrease the effect of direct backing of test material by metal plate, which influences measurement accuracy if two-layer method is used. The structure permits a suitable electric field interrogation in test material and decreases the influences of both radial and surface waves. FDTD method was adapted for modeling the problem geometry to calculate the reflection coefficients since a probe with finite flange size is used. Measurements were carried out using the proposed technique to determine complex permittivity and complex permeability of several radar absorbers over X-band applications of microwaves. In comparison with both single-layer and two-layer methods results, the measured results of these parameters agreed well with the published data. by companies and literatures.

Multilayer Structure Technique for Improving Determination of Electromagnetic Properties of Radar Absorbers Based on Two-Layer Method and Flanged Rectangular Waveguide Probe

This paper presents further development of utilization of two-layer method to perform nondestructive electromagnetic properties determination of planar radar absorbers using flanged open-ended rectangular waveguide probe. A multilayer structure of three layers was proposed to improve the measured results of these parameters obtained using two-layer method. These layers were arranged such that the test material is sandwiched between two known low loss materials to provide the needed two independent reflection coefficients necessary to extract them at different conditions of testing. The proposed structure was aimed to decrease the effect of direct backing of test material by metal plate, which influences measurement accuracy if two-layer method is used. The structure permits a suitable electric field interrogation in test material and decreases the influences of both radial and surface waves. FDTD method was adapted for modeling the problem geometry to calculate the reflection coefficients since a probe with finite flange size is used. Measurements were carried out using the proposed technique to determine complex permittivity and complex permeability of several radar absorbers over X-band applications of microwaves. In comparison with both single-layer and two-layer methods results, the measured results of these parameters agreed well with the published data. by companies and literatures.

Flow Simulations of Modified Diffuser Augmented Wind Turbine

In order for wind technology to compete with conventional sources of energy, in terms of energy production costs, researchers are working on different ways to increase the energy density in wind. Development of wind power augmentation system is one of the most promising concepts in this field. The main objective of this research is to propose a new diffuser design for Diffuser Augmented Wind Turbine (DAWT) by introducing air vents and vortex generators. This study also investigates the effect of wind velocity and air pressure on the proposed modified diffuser to develop a suitable diffuser for DAWT. The purpose of this modified diffuser is to create a low-pressure region in the centre of the diffuser to increase the inlet mass flow rate. Three modified designs were developed and were simulated using CFD techniques. Results showed an outstanding increment in wind speed, which is 8.56 m/s (2.14 times increment), over the 4 m/s initial wind speed in a modified diffuser (Model 3 Air vents with splitter). This modified diffuser is based on the parameters: rotor diameter (D) = 500 mm, diffuser length (L) = 1000 mm, diffuser open-angle (θ) = 12º, flange size = 221.73 mm and inner splitter with 14º open-angle (α).

Tension–bend–shear capacity of bolted-flange connection for square steel tube column

In this study, the square steel tube column is connected by bolted flange instead of traditional welding. For multi-rise structure, tension, bending moment, and shear force may act on the connection under vertical and horizontal loads. To investigate the mechanical behavior of flange connections, full-scale model tests and finite element analyses of 10 bolted-flange joints were carried out. The mechanical properties of the specimens and the influence of the flange thickness, flange size, and bolt hole diameter under a tension–bend–shear combination were obtained. The size of the bolt hole and flange has little effect on the load-carrying capacity of the connection. With the increase of the thickness of flange, the flexural rigidity and load-carrying capacity of the connection increase obviously, and the yield mechanism of the specimen changes from flange yield to bolt yield. The influence of the axial tension ratio on the bolt tension was investigated by the experiment-verified finite element models. The axial tension ratio is the value that the axial force of column divided by the cross-sectional area and the material design strength of the column. Increasing the axial tension ratio may increase the bolt tension, which has a harmful effect on the bolts at the tension side of the flange. Using yield line theory, formulas for calculating the static load-bearing capacity resisting the bending moment, shear and tension were deduced and verified by comparing with the result of experiment and finite element analysis.

Q690 high strength steel T-stub tensile behavior: Experimental and numerical analysis

To evaluate the tension behavior of welded high strength steel (HSS) T-stub joint accurately, an experimental study on the mechanical properties of welded T-stub joints with nominal yield strength of 690MPa under tensile load was conducted. This experimental program includes twelve welded T-stub joints varying with bolt diameter, bolt strength grade, and flange size. Plastic bearing capacity and initial stiffness were obtained from the test and compared with the EC3 Part 1-8 predicted ones. A simplified finite element model considering the nonlinearity of material, geometry and contact was developed and verified in order to perform an extensively parametric study. The effects of flange thickness, bolt pretension and stiffener on the mechanical properties of joints were investigated and discussed. The test results show that the methods proposed in EC3 Part 1-8 for plastic bearing capacity calculation and identifying the failure mode can be applicable to HSS T-stub joints, but the methods evaluated with initial stiffness overestimate the initial stiffness of the joint. The parameter analysis results show that when the flange boundary condition close to simply supported or fixedly supported, the effect of which on the initial stiffness of the joint should be taken into account. The initial stiffness of joint increases linearly as the bolt pretension increases. However, when the pretension exceeds the standard value, an increase in pretension exerts a weak influence on the initial stiffness. When the length-height ratio of stiffener is lower than 1.0, the post-limit stiffness degenerates remarkably, and thus the ductility gets worse.

Shear behaviour of hybrid fibre-reinforced SCC T-beams

Three series of simply supported hybrid-fibre-reinforced self-compacting concrete T-beams subjected to four-point symmetrically placed vertical load were experimentally investigated. The influence of the following variables was studied: the fibre type, the fibre content, the stirrup ratio and the flange size. Failures were consistently shear or shear–flexure failures, except in five T-beam specimens where the failure was dominated by flexural cracks. The results showed that hybrid fibres can evidently enhance the ultimate shear load. The addition of hybrid fibres in adequate amounts can change the failure mode. The influence of different flange size on the ultimate shear load of the T-beams should be considered. Three methods were proposed – the ‘effective width’, ‘form factor’ and ‘shear funnel’ – for predicting the ultimate shear load of steel-fibre-reinforced self-compacting concrete T-beams, and another two methods were proposed – the ‘revised σ–w design method’ and ‘revised σ–ε design method’ – for predicting the ultimate shear load of hybrid fibre or steel-fibre-reinforced self-compacting concrete T-beams. The ultimate shear load recorded experimentally was compared with the value obtained from the proposed equation. The ‘revised σ–w design method’ was more suitable for predicting the ultimate shear load of T-beams containing hybrid fibres and/or with stirrups, and the correlation was satisfactory.

Designing a high temperature high pressure mesh sensor

Abstract State-of-the-art turbulence models are expected to accurately predict flow behavior in a wide range of geometries and flow conditions for a wide range of fluid properties. These models rely on accurate time resolved measurements of scalar and vector flow variables. One such measurement technique for obtaining a high density of flow field variables with high time resolution is in the form of electrode-mesh sensors (WMS) which measure the local instantaneous electrical conductance of a flow at a large number of positions, typically in the cross-section of a conduit at frequencies up to 10 kHz. Extensive studies on single and multiphase flows have been carried out with mesh sensor technology in the past 15 years, often focused on flows directly related to nuclear power generation. However, essentially all of these experiments have taken place at low temperatures ( A new mesh sensor construction has been designed at the ETH Zurich for operation in high temperature and pressure pipelines by implementing novel materials, assemblies and a new sealing methodology. The mesh sensor package design is scalable so as to be compatible with standard flanged pipelines of size estimated to be DN10. The new design solves the problems discussed related to prior state of the art while at the same time allowing the sensor to operate at higher temperatures and to be manufactured and assembled more easily and more cheaply. The pressure barrier is no longer guaranteed by an epoxy, as in prior state of the art developed by other researchers, but rather by a standard graphite gasket between the sensor housing flanges, the same type that would normally be sealing a bolted flange joint, and commercially available threaded sealing glands. While still maintaining space for the standard number of bolts for a given flange size, such sealing glands could conceivably allow for a very high number of electrode signals to be extracted. The ability to carry a large number of conductors through the pressure barrier, in addition to the housing flange design, enables the installation of multiple mesh sensors, three layer sensors, or other instrumentation such as thermocouples, enabling the reconstruction of additional flow properties from measured data such as velocity and interfacial area concentration. A 16-transmitter, 16-receiver prototype sensor has been constructed for a DN80 pipeline; its individual components and some assemblies thereof have been tested in an autoclave at temperatures up to 285 °C in a liquid water-vapor environment with boiling at saturation pressure. Furthermore, a test section construction has enabled the sensitivity of the sensor to temperature changes via the variable electrical conductivity of deionized water as a function of temperature to be investigated.