Interference Fit Research Articles

Expandable HP/HT Liner Hanger Increases Pressure Integrity

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 29494, “HP/HT Expandable Liner Hanger Technology With Superior Pressure Integrity,” by Edward S. Royer and Robert A. Turney, TIW, A Drill-Quip Company, prepared for the 2019 Offshore Technology Conference, Houston, 6–9 May. The paper has not been peer reviewed. Copyright 2019 Offshore Technology Conference. Reproduced by permission. This paper describes a high-pressure/high-temperature (HP/HT) expandable liner hanger product that offers metal-to-metal and elastomer sealing capabilities at the liner top in the host casing. The system delivers increased hanging capacity and seal integrity for installing casing strings of various lengths. The expansion process is achieved using a multipiston hydraulic running tool with pressure application to displace an expander inside the hanger body. Expandable Technology Expandable technology provides operators an alternative to conventional liner hanger and packer systems that typically use slips and cone components configured on the outer diameter of a hanger body that require translation of the slips onto the cone for installation of the liner hanger in the host casing. Conventional liner-top packer systems typically also require drillstring weight for the mechanical force required to energize a sealing element that produces the annular seal between the liner and host casing strings. Fig. 1 shows a comparison between a conventional liner hanger and packer system and the system described by the authors of the complete paper. Expandable liner hanger and packer technology has evolved from years of product development and has gained market share with the increase of successful field installations. These systems consist of an integral hanger body design that incorporates elastomeric sealing elements normally bonded on the outer diameter. Hanger body expansion into the host casing is accomplished with the application of hydraulic pressure through a setting tool to create enough force to displace an anvil through the hanger body inner diameter. Interference between the hanger body inner diameter and the anvil outer diameter creates the interaction necessary for the creation of radial growth required to facilitate interference with the host casing. The described system differs from other expandable systems in its propagation of expansion using a proprietary tool that is a tubular component with a distinctive outer diameter profile. This tool, known as the expander, is displaced with an interference fit inside the system’s integral hanger body to create the expansion needed to anchor and seal to the host casing. A multi piston hydraulic running tool, with pressure activation initiated by liner wiper-plug displacement during cementing or a setting ball dropped from the surface, applies force to displace the expander and carries the liner (which is of Q-125 material grade) downhole. The expanding tool is permanently installed inside the hanger body. The contact pressure generated during the expansion process is preserved, which ensures an installation with enhanced anchoring ability that provides the added benefit of high collapse resistance from annular pressure. Multiple segmented slips are installed and retained in machined pockets oriented on the circumference of the hanger body. Elastomeric sealing elements are installed on the hanger body’s outer diameter bordered by metal seal ribs. The combination of metal and elastomer sealing elements provides redundancy for ensuring pressure integrity at the liner top. The system allows a large inner diameter after setting.

A Quantitative Model to Calculate Gas Sealing Capacity and Design Sealing Parameters for Premium Connection

The present research studies about sealability of premium connection almost focus on qualitative description by sealing contact stress distribution, which is not convenient for sealing capacity evaluation and sealing parameter design. This paper proposes a quantitative model to calculate directly gas sealing capacity of cone to cone premium connection, different from the usual finite element method with testing, which combines the elastic thick wall cylinder interference fit theory for calculating sealing stress with the gas sealing criterion obtained from Murtagian’s experimental results. With the proposed model, the effects of pipe wall thickness, seal cone taper, radial sealing interference, and axial sealing length on the gas sealing capacity have been investigated. Furthermore, the gas sealing capacity envelope curve based on radial sealing interference and axial sealing length is also calculated and a new sealing parameter design method is proposed for cone to cone premium connection. The results show that the internal upset pipe is good for sealability, and increasing both radial sealing interference and axial sealing length can significantly enhance gas sealability while seal cone taper has an unobvious effect on it. To meet sealing capacity, the designed sealing parameter combination (δd, Ld) should be located in the upper right region of the gas sealing capacity envelope curve.

Damage behavior investigation of CFRP/Ti bolted joint during interference fit bolt dynamic installation progress

Interference fit can significantly enhance the tensile and fatigue strength of CFRP/Ti bolted joints, however, the damage can occur during interference fit bolt installation progress. Therefore, an experimental study was conducted to understand damage behaviors of the joint during the interference fit bolt installation progress using dynamic installation method based on electromagnetic dynamic force. The installation resistance was evaluated and the damage mechanism was discussed. Moreover, the influence of interference size on damage behaviors was also studied. The test results demonstrated that the installation resistance exhibited two typical stages and mainly generated by Ti plate, which agreed with theoretical analysis. Damage modes of the joint were dominated by CFRP damage and significantly influenced by interference size. The internal damage mainly occurred in the entrance and the exit of the hole in CFRP, especially, the first ply along the installation direction was the most critical ply, on which a typical damage ring was observed. The dynamic installation method can reduce the damage and the layer deflection of CFRP, which is suggested to be used to improve joint designs.

Inadequate Metadiaphyseal Fill of a Modern Taper-Wedge Stem Increases Subsidence and Risk of Aseptic Loosening: Technique and Distal Canal Fill Matter!

BackgroundAdequate interference fit and mechanical stability through optimal surgical technique are essential to prevent subsidence and loosening in cementless total hip arthroplasty. The purpose of this study is to determine the effect of surgical technique on radiographic subsidence and subsequent stability of a modern taper-wedge cementless stem. MethodsA retrospective review of 250 consecutive cementless primary total hip arthroplasties performed by 2 surgeons was completed. Surgeon A vigorously broached, maximizing the mediolateral stem dimension and confirmed final broach stability with a torsional test, whereas Surgeon B did not. All patients received identical taper-wedge stems. Preoperative bone morphology (canal flare index), postoperative subsidence, and canal fill were radiographically assessed. ResultsCanal flare index was not different between groups (P = .747). There was significantly less subsidence at 1 month for Surgeon A (0.3 vs 1.3 mm, P < .001). Additional subsidence at 1 year occurred in only 0.8% of Surgeon A (1/119) compared to 51.6% of Surgeon B stems (33/64, P < .001). Surgeon technique and canal fill measured at 60 mm below the lesser trochanter were the only variables predictive for subsidence, where Surgeon A and B had a mean canal fill of 95% and 86%, respectively. Surgeon B had 2 cases of aseptic loosening (2%) at 2 and 3 years postoperatively. ConclusionThese observations support that maximizing mediolateral canal fill and avoiding under-sizing the femoral implant with meticulous broaching technique minimizes subsidence and optimizes stability of modern cementless taper-wedge stems. Failure to optimize canal fill with appropriate broaching and surgical technique may predispose femoral components to failure from aseptic loosening.

Experimental Analysis of Interference-Fit Joining of Aluminum Tubes by Electromagnetic Forming

This study investigates the main parameters that influence the strength of tubular component joints fabricated by electromagnetic compression, more specifically, interference fit by crimping tubes into mandrels. The mechanical parameters are the residual stress on the mandrel, the joining area, and the interfacial friction coefficient between the tube and mandrel. These parameters have a considerably complex relationship with electromagnetic compression process parameters, starting with the charging energy and distribution of magnetic pressure pulse that trigger the forming process, the initial gap between joining partners, the material components and geometry, and the shape and surface roughness of mandrel. This work investigates the interference-fit joining of AA6082-O aluminum alloy tubes with mandrels made of different materials (AISI 1045, AA6082-O, and AA6082-T6) and fabricated under different metallurgical conditions. The process is gradually analyzed by systematically considering the influence of other process parameters, such as the initial gap between joining partners, energy pulse, field shaper geometry and its resulting magnetic pressure, and mandrel material and surface roughness in order to fabricate joints with maximum strength. The derived results indicate, apart from the initial gap, the importance of the mandrel surface roughness and the field shaper geometry on the joint strength and its associated failure mechanism. These are presumed to be important contributions to the development and industrial implementation of EMF technology.

A comparative analysis of adhesive bonding and interference fitting as joining technologies for hybrid metal-composite gear manufacturing

The aim of this work is to compare two different joining technologies for steel and carbon fibre reinforced polymer materials in a hybrid gear in order to improve the dynamic behaviour in terms of natural frequencies and damping properties. A comprehensive approach for the design and prototyping of hybrid metal-composite gears with interference fitting and adhesive bonding is provided. In a following phase, an accurate description of the experimental impact tests is shown in order to investigate modal performances. Successively, in a finite element environment, modal analyses are conducted and frequency response functions of the gear model are analysed by means of complex stiffness matrix that accounts for structural damping. Impact tests and simulations indicate that the solution with interference fitting is stiffer than the one with adhesive, even if the damping capacity is lower. The results for both technologies show that it is possible to enhance noise and vibrations behaviour of gears through the application of composite materials in place of conventional full-metal solutions.

Experimental Evaluation for the Interference-fit Electromagnetic Rveting Joint with Headless Rivet

Electromagnetic riveting (EMR) technology as a relatively new mechanical joining process has many advantages compared to traditional riveting methods. However, it needs to be investigated whether the traditional pressing riveting can be replaced by EMR process in aerospace manufacturing engineering. Therefore, in this paper, the differences of riveting quality between automatic riveting and handheld EMR were compared by riveting and mechanical experiments including the uniformity of interference fit, shear and pull-off strength and fatigue life of the joints respectively. It was observed that the interference fit of the riveting joint using EMR is more uniform along the axial direction of rivet than that of automatic riveting. In addition, the overhang of the rivet was difficult to control by handheld EMR, so the quality of rivets for EMR was poorer than that of automatic riveting. Thus, the shear and pull-off strength and fatigue life of EMR joints were affected by the quality of rivets, and a longer rivet is needed for the EMR.

A simple and rapid method for blood plasma separation driven by capillary force with an application in protein detection.

Blood plasma separation is a vital sample pre-treatment procedure for microfluidic devices in blood diagnostics, and it requires reliability and speediness. In this work, we propose a novel and simple method for microvolume blood plasma separation driven by capillary force. Flat-shaped filter membranes combined with hydrophilic narrow capillaries are introduced into devices, in order to reduce the residual volumes of blood plasma. An interference fit is used to ensure no leakage of blood or cells. There is desired trapping efficiency of blood cells in the devices. The method provides high efficiency with a plasma extraction yield of 71.7% within 6 min, using 60 μL of undiluted whole human blood with 45% haematocrit. The influence from structural parameters on the separation kinetics and the dependence of the haematocrit levels on the separation efficiency are also investigated. The total protein detection shows considerable protein recovery of 82.3% in the extracted plasma. Thus, the plasma separation unit with a very simple structure is suitable for integrating into microfluidic devices, presenting promising prospects for clinical diagnostics as well as for point-of-care testing applications.

Analytical solution to thermal stresses of high speed PM rotor considering thermal load and heat convection

Aiming at the high speed permanent magnet (PM) rotor with the heat source, this work investigates the analytic solution to the transient temperature field and thermal stress field of the rotor, considering the influence of the forced air cooling of rotor surface on the stress field. Firstly, dimensionless formulation of the transient heat conduction equation including interior heat source is derived, where the axially non-uniform heat convection coefficient and the temperature of main flow region are equivalent to their mean values. Secondly, the Fourier integral transform method is used to solve the dimensionless heat conduction equation. Then, the obtained temperature field is loaded into the analytical solution of strength, in which three types of stress sources such as interference fit, centrifugal force and temperature gradient are included. Finally, examples are carried out to verify the analytical solutions and relative results are discussed.

The method for determining the amount of interference formed during the assembly of the rim and disk of the wheel of automobile and tractor

The disk-rim system is a complex structure with a variety of properties that have not yet been fully studied. The vehicle wheel is an axisymmetric structure consisting of a rim and a disk for attaching it to the hub. On the one hand, the outer diameter of the disk (flange) is welded around the circumference to the inner diameter of the rim (shelf), forming a rigid one-piece connection. On the other hand, using a bolted connection, the disk is attached to the hub, forming a wheel-hub assembly. The assembly line of the rim and wheel disk of a truck consists of the following technological operations: pressing the disk into the rim, welding the outer seam, welding the inner seam, cleaning the surface from welding spatter, punching the valve hole, curing burrs on the valve hole, and controlling the runout. When pressing the disk into the rim, it is necessary to know the amount of interference, as well as the distribution of radial and tangential stresses. Determining the amount of interference is an urgent task, since this characteristic is fundamental when assembling the rim and wheel disc. It was found that for radial stresses the compression is observed. Its largest value is located at the boundary of the disk and the rim. For tangential stresses the tension is observed. Its largest value is located at the boundary of the disk and the rim. Calculations showed that for a 400 mm wheel disk, a 300 mm wheel rim an elastic modulus is 2∙104 MPa, a force modulus is 600 MPa, an interference fit is 0,0865 mm.

Bond strength in wood filled rectangular hollow steel tubes

The objective of this paper is to present experimental work on bond strength of mechanical and adhesive bonded teakwood filled rectangular sectioned hollow steel tubes. Bond between the wood and steel tube interface is due to interference fit between wood and steel tube, confinement of teakwood due to steel tube and friction between teakwood and steel tube. To enhance the bond strength multipurpose epoxy adhesive for structural application was used. Pull out tests were carried out on universal testing machine to study the bond behaviour. Load Vs slip curves were drawn for both mechanical and adhesive bonded wood filled steel tubes. Use of adhesive at wood steel interface changed bond behaviour significantly. It was observed that bond strength of adhesive bonded wood filled steel tube was 2.58 times greater than that of mechanical bonded wood filled steel tubes.

The Influence of Centrifugal Force on the Interference Fit of High-Speed Electric Spindle

The letter presents an analysis of interference fit of the electric spindle at different rotor speeds due to the influence of centrifugal force and provides a theoretical formula showing the relationship of the speed, stress on the rotation speed. The letter also established a finite element model of the interference fit. The study found that as the rotation speed increases, the interference and contact stress between the spindle and the rotor gradually decrease, and the reduced speed is proportional to the square of the rotation speed.

КРИТЕРІЙ ВИБОРУ РАЦІОНАЛЬНИХ ЗНАЧЕНЬ ПАРАМЕТРІВ ПОСАДКИ З НАТЯГОМ ПРИ АВТОМАТИЗОВАНОМУ ПРОЕКТУВАННІ

The proposed scientific work considers and substantiates a new approach to selection of rational values of basic geometrical parameters of interference fit at their automated design – a fitting diameter and working length. A geometric and analytical model of the area was constructed, in which there are values of the basic parameters of fit. Then, numerical and analytical researches of this model were carried out. Based on the results of this research, an analytical criterion for choosing rational values of geometric parameters is formulated. The proposed method is based on the definition of the center of intersection of the largest segments of the permissible ranges of changes in the values of diameter and working length. This center is represented as some coordinate point within the model in the two-dimensional coordinate system. The coordinate axes of this model use the fitting diameter and the fitting length. The position of this point is analytically described using the mathematical apparatus of the theory of R -functions. These parameters are used in the automated design of the interference fits on the smooth cylindrical surface for jointed components of the direct engagement mechanical gears, for example, for the bandage joint of the ring gear to the wheel hub. This does have a keyless joint, the torque is fully transmitted by the friction forces in the fit. Such joints are used in the units and mechanisms used in small arms and artillery and military equipment, as well as other technical products of general-engineering purpose at various methods of assembly by a method of full interchangeability. The effectiveness of the method is shown in a specific example of numerical calculation, the results of which are obtained using the software developed by the team of authors of this work

Flexor Hallucis Longus Tendon Single-Incision Transfer Stabilized With Autologous Bone Fixation

Flexor hallucis longus transfer is routinely used as a technique to salvage a chronic or neglected Achilles tendon rupture. The single-incision (or short harvest) technique provides adequate graft suitable for fixation with interference screws. We have used a bore corer instead of a drill to establish the tendon tunnel and at the same time use the harvested autograft for interference fit and avoid the use of screws, providing what we consider to be a more biologic form of fixation.

Contact mechanical behaviors of radial metal seal for the interval control valve in intelligent well: Modeling and theoretical study

AbstractIntelligent wells equipped with the interval control valve (ICV), which have the potential applications to significantly improve oil production or control the water production of wells and fields, are more and more widely utilized in the oilfields. The radial metal seal of an ICV is intended to isolate the flow of produced fluids between the casing annulus and the well tubing. The contact mechanical behaviors of the radial metal seal are essential to the structural design and reliability of ICVs in the intelligent well. In this paper, the two‐dimensional axisymmetric assembly of the radial metal seal and the closure member is abstracted as a combination of interference fit model and cantilever beam model. Based on that, the related theoretical model, between the radial metal seal's contact stress and its independent variables, has been derived. Next, numerically simulations of contact stress between the radial metal seal and the closure member for different independent variables are conducted by the finite element method (FEM) to validate the theoretical model. It is found that the mean absolute value of relative error between the numerical and theoretical results of the contact stress is approximately 10%. Additionally, the structural parameters of the radial metal seal are proposed with the absolute value of relative error &lt;10%. Furthermore, the value of the contact stress based on the cantilever beam model can be used to calculate an approximation theoretical solution. In summary, the proposed theoretical model provides a foundation for the design, improvement, and selection of radial metal seal under the known oilfield conditions.

Measuring the static shear strength of anaerobic adhesives in finite thickness under high pressure

ABSTRACT Although anaerobic adhesives are extensively used in addition to mechanical tightening in flanged couplings, interference fits, and threaded connections, their constitutive behaviour still needs to be investigated. According to the micromechanical model proposed by Dragoni and Mauri [Proc. of the IMECHE Part L J. of Mat.: Des. and Appl. 2002; 216: 9–15], the shear strength of the anaerobic adhesives significantly improves with the contact pressure applied to the thin adhesive layer. In order to assess this hypothesis, this work investigates the shear strength of an anaerobic adhesive layer with finite thickness and surface area, subject to a nearly-uniform contact pressure, up to 1000 MPa. The tests involved a head to head bonded specimen, made of high strength steel adherends (39NiCrMo3), with a controlled roughness on the bonding surfaces. Both a weak and a strong anaerobic adhesive (Loctite 243 and Loctite 638) are investigated. A full-field technique, such as the Digital Image Correlation, was used in order to detect the 3D displacement and strain fields, and to evaluate the twist angle of the entire external surface, with particular attention to the interface area. The preliminary results prove the reliability of the test bench and confirms the piezo-resistive response of the anaerobic adhesive.

Effect of the interference fit on the stress distribution and failure mode of a flat-head riveted GLARE joint

Glass laminate aluminium reinforced epoxy (GLARE) is an ideal material for fuselage skin, and a rivet joint is the most reliable way to connect fuselage skin. Due to the complex deformation of the joints and the effects of the riveted residual stress, the tensile failure modes are complex and difficult to predict during the service stage. A 3D constitutive model was employed to analyse the mechanical and failure behaviours of the flat-head rivet joints of GLARE during the entire process from riveting to stretching. Under different fibre orientations of GLARE, the effects of the riveting interference on the stress distribution during riveting, the residual stress and the failure mode were investigated. The compressive stress and bending stress when the fibres were in the 0° direction are the main load modes during riveting, but only the bending stress in the 0° direction becomes residual stress. If the bending stress is more highly concentrated in a fibre layer, there is greater damage accumulation in the layer. Since a high interference fit may also cause the shear fracture of the rivet and serious interface delamination, the riveting interference should be under strict control against the different fibre orientations of GLARE.

About a new approach to calculating spiral clamps

The bearing capacity of spiral clamps, which are mounted on wires (cables) for their tension, connection, repair, etc., is studied. The design of spiral clamps is formed from stretched spirals that are wound onto conductors with an interference fit, which makes it possible to obtain tensile connections practically inseparable. The general problem of the interaction of spiral clamps and overhead line conductor layers is formulated. Different asymptotic solutions are given for initial and boundary value problems, and the design parameters of spiral clamps are determined to provide their carrying capacity. A wire layer is represented by the energy approach as an equivalent anisotropic elastic cylindrical shell, and wire construction as a whole is considered as a system of cylindrical shells inserted each other and interacting by forces of pressure and friction. The equivalence of the elastic properties of the shell to the properties of the wire layer is established using energy averaging. The constitutive relations obtained using the Castigliano theorem relate the generalized displacements and the corresponding forces. The matrix in these ratios is a stiffness matrix or flexibility matrix of a spiral wire structure. Such approach allows variety of interaction problems for spiral clamps with conductor layers to be solved, and the force transfer mechanism to be investigated from common positions. Static equations are written from the equilibrium of the elementary shell ring. It is considered that the length of the clamp is so great that the mutual influence of its ends can be neglected; the clamp is modeled as semi-infinite shell. This model allows the different initial and boundary value problems to be formulated, depending on the boundary conditions and clamp mounting methods on a conductor.

An Experimental and Numerical Analysis of the Compression of Bimetallic Cylinders.

This paper investigates the upsetting of bimetallic cylinders with an aluminum alloy center and a brass ring. The influence of the center-ring shape factor and type of assembly fit (interference and clearance), and the effect of friction on the compression force and ductile damage are comprehensively analyzed by means of a combined numerical-experimental approach. Results showed that the higher the shape factor, the lower the forces required, whereas the effect of friction is especially important for cylinders with the lowest shape factors. The type of assembly fit does not influence the compression force. The accumulated ductile damage in the compression of bimetallic cylinders is higher than in single-material cylinders, and the higher the shape factor, the lower the damage for the same amount of stroke. The highest values of damaged were found to occur at the middle plane, and typically in the ring. Results also showed that an interference fit was more favorable for preventing fracture of the ring than a clearance fit. Microstructural analysis by scanning electron microscopy revealed a good agreement with the finite element predicted distribution of ductile damage.

Prediction of Tensile Strength in Friction Welding Joins Made of SA213 Tube to SA387 Tube Plate through Optimization Techniques.

In modern times, the Industry X.0 has emerged as the paradigm that has become the core of digital technology-driven business organizations. Further, this paper establishes a tube to tube plate friction welding technology with the help of deploying an external tool, also known referred to as the FWTPET scheme. Besides, the SA213 tube and SA387 tube plate were combined by employing a unique interference fit technique. Also, the strength of this combined portion was assessed with and without the aid of a holding block. Subsequently, the analytic optimization approaches like genetic algorithm, analysis of variance, and Taguchi L9 orthogonal array design were deployed in the prediction of the optimum joining strength. Moreover, the input parameters include the projection of the tube (mm), the rotational speed of the tool (rpm), and depth of cut (mm); besides, the tensile strength is considered as the output parameter. Also, the grain size distribution around the weld zone and the presence of base metal were measured through an optical microscope as per ASTM linear intercept method. Further, it is evident that grain refinement had occurred in the weld zone, which in turn increases the tensile strength. The exceptional weld strength (tensile strength) was obtained when joining of SA213 tube and SA387 tube plate through interference fit using a holding block without a hole in the tube. Experimentally, it was found that the achieved tensile strengths were 836.8 MPa (without a hole) and 789.35 MPa (with hole) using the holding block, respectively. Additionally, it was found that in the absence of a holding block, the achieved tensile strength is 762.2 MPa (without a hole), and 700.8 MPa (with a hole), correspondingly. The deviation of tensile strength between the predicted (genetic algorithm) and experimental was found minimal. Therefore, for achieving this strength, the suitable operating parameters set include the rotational speed of the tool (1300 rpm), projection of the tube (1 mm), and depth of cut (0.5 mm) with backing block configuration.