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When shafts and gears are assembled with an interference fit, the tight connection between the two parts is achieved through deformation. To maximize the amount of torque the gear assembly can transmit, it becomes necessary to apply the maximum possible interference fit. However, this will cause areas of high stress in the gear root and deformations that adversely affect the contacting surfaces of the gears. In this work, the modified gear tooth surfaces that provide the desired meshing and contact conditions considering the deformations caused by the interference fit assembly will be established. For that, a finite element (FE) model will be developed to simulate gear-shaft interference fits by the finite element method. The FE model will comprise the entire gear along with the corresponding portion of the shaft, replicating the intended interference fit. Consequently, the model will enable the determination of the stresses at the root of the gear teeth as well as the deviations throughout the active gear tooth surfaces. With them, the deviated gear tooth surfaces will be reconstructed and virtually inspected by using the IGD computer program. Thus, the deviations caused by the interference fit will be assessed and the needed modifications of the gear tooth surfaces established to have these deviations compensated. A numerical example of design and compensation of deviations caused by interference fit assembly is presented. [ABSTRACT FROM AUTHOR]

Aeroengine power turbine rotor is a typical nonlinear rotor system, in which the interference connection between long shaft and short shaft has a prominent influence on the coupling vibration of the system, especially at high speed, the nonlinear stiffness change of interference contact is more obvious. Therefore, the paper considers the change of the contact characteristics of the long shaft and the short shaft of the turbine rotor, and the nonlinear restoring force of the bearing to analyze the dynamic characteristics of the rotor. Firstly, according to the theory of elasticity, the contact parameters under different speed states are calculated, the contact stiffness model under interference fit is established, and the relationship between contact stiffness and speed is analyzed. Secondly, according to the Hertz contact theory, a bearing nonlinear restoring force model considering time-varying characteristics is established. Finally, the dynamic model of the bearing-flexible rotor coupling considering interference contact is established. The influence of contact parameters and unbalance parameters on the nonlinear vibration characteristics of the rotor is analyzed by amplitude-frequency curve, bifurcation diagram, time-domain waveform, spectrum diagram, trajectory diagram and Poincaré diagram. In addition, the simulation results are compared with the experiment results of the rotor test rig to verify the accuracy of the established dynamic model. By analyzing the influence of different parameters such as interference magnitude, unbalance position, unbalance magnitude and unbalance couple on the nonlinear vibration of the rotor, the basis for the design and vibration control of the cantilever turbine rotor is provided. [ABSTRACT FROM AUTHOR]

The electromagnetic force dynamic installation (DI) method of interference fit fasteners has significant advantages in improving the quality of the assembly interface of composite structure. This study aims to investigate how improving assembly interface quality may help in achieving high‐precision interference‐fit joints in composites. Single‐lap joint specimens were prepared using electromagnetic installation technique, the fatigue life and failure behaviors of the joints under different bolt‐hole clearances were measured and analyzed experimentally. In addition, a three‐dimensional finite element model was developed to predict the radial pre‐compression stresses around the hole and the progressive failure behavior of various typical damage modes in carbon fiber‐reinforced polymer induced by the interference. The results show that the critical interference range for the DI‐composite bolted structure is 1.0%–1.2%. The fatigue life of the best interference (1.0%) and the worst interference (0%, neat fit) have a difference of 36 times in amplitude. The residual stress with uniform distribution and high amplitude reduces the stress concentration of the hole wall and improves the failure evolution of the loaded hole. The contribution of this study provides vital guidance for improving the fatigue performance of CFRP bolted structures using a novel DI method. Highlights: I = 1.0% is the critical damage‐enhancing interference size for dynamically installation interference fit bolts with electromagnetic forces.The residual stress amplitude introduced by the interference does not increase uniformly as the interference size increases. Excessive interference significantly reduces the uniformity and magnitude of residual stresses.Under subsequent cyclic loading, the fifth layer near the inlet and outlet of the extruded lower laminate appears to be the critical ply of extrusion deformation, and severe damage is concentrated in the critical ply of deformation.The decrease of stress amplitude and the variation of mean stress are the mechanisms of fatigue life enhancement in interference fit joints under external cyclic loading. [ABSTRACT FROM AUTHOR]

Purposes The stress on the metro wheel is complicated, which is not only influenced by the wheel-rail coupling force and the contact pressure induced by the axle-wheel interference fit, but also by the thermal load generated during braking. Methods In this paper, a metro wheel with single S-type spoke plate is taken as the research object. The finite element model of the wheel is established in ABAQUS software and the influence of the axle-wheel interference fit is analyzed on the mechanical stress distribution of the wheel under the straight-line load condition. The thermal-mechanical coupling model of the wheel is established at tread braking under the turnout load condition. The direct coupling method is used to study the variation of the temperature and stress fields of the wheel. Effects of mechanical stress and thermal-mechanical coupling stress on the structural strength of the wheel under different wear levels are studied. Findings Results show that the thermal load mainly affects the structure near the tread, while the part near the hub is greatly affected by the interference fit. The maximum difference of coupling stress between the new wheel and the worn-to-limit wheel is up to 69.3 MPa. The coupling stress of the wheel is relatively stable within the diameter range of 820-840 mm, with a float of only 9.1 MPa. Conclusion This study provides scientific reference for the structural design of metro wheels and can give a good guidance for the maintenance work.

Highlights Matrix crack propagation and stiffness degradation behaviors of the carbon fiber reinforced polymer/titanium alloy (CFRP/Ti) bolted joint were characterized by a synergistic damage mechanics approach. The parametric study including pre‐tightening torques and interference fit sizes was conducted. The results showed that the joint stiffness degradation exhibited characteristics of local stiffness degradation due to local stress concentration. Stiffness degradation in different plies was caused by matrix crack damage occurring in different directions. The pre‐tightening torque significantly increased the joint stiffness and restrain matrix crack progression, effectively inhibiting the stiffness degradation of the joint. Moreover, the low interference fit level delayed the crack initiation in −45° ply and 45° ply and the crack propagation of the laminate, while promoted the crack initiation in 90° ply. The stiffness degradation of the laminate could be significantly reduced by interference fit. Matrix crack propagation and stiffness degradation behaviors of the CFRP laminate were characterized by a synergistic damage mechanics method. A FE model of the CFRP/Ti double‐lap interference fit bolted joint was established. Influences of pre‐tightening torques on both matrix crack initiation and propagation were investigated. The optimum interference fit size of the matrix damage strengthening was 0.20%–0.60%. [ABSTRACT FROM AUTHOR]

Drive systems are an important part of general mechanical engineering, automotive engineering, and various other fields, with shaft–hub connections being an important part of such systems. Decisive aspects in the development of such systems today are, for example, high transmittable forces and torques, low masses, and the cheapest possible production of components. A possibly threefold increase in the force and torque transmission capacity can be achieved by using press–fit connections with an elastic–plastic design as opposed to regular elastically designed alternatives. An elastic–plastic design of the press–fit connection is achieved by using a large interference. A large transition geometry on the shaft (which replaces the conventional chamfer) is required to join such an interference. The material and space requirements have a negative impact on lightweight applications and limited building spaces. Therefore, the objective of the research presented in this paper is to design and analyze a detachable joining device that substitutes this geometry. A simulation study was conducted to determine the geometry of the joining device that improves the stress state and consequently the force and torque transmission capacity of the connection. Moreover, the influence of manufacturing tolerances of the joining device and the shaft, corresponding risks, and measures to mitigate them are analyzed using finite element analysis. The results show that large transition radii, enabled by using a joining device, lead to a homogenous distribution of plastic strain and pressure in the press–fit connection, even for large interferences ξ and soft hub materials like wrought aluminum alloys. The influence of manufacturing tolerances on the stress state was quantified, leading to design guidelines that minimize the risk of, e.g., the front face collision of a shaft and hub, while maximizing the power transmission of the connection. The results show the capability of a detachable joining device to enable elastic–plastic press–fit connections and the corresponding threefold increase in the force and torque transmission capacity in lightweight applications, resulting from the substitution of the installation space consuming and mass increasing the transition geometry of the shaft. [ABSTRACT FROM AUTHOR]

The success of uncemented total ankle replacement (TAR) is linked to initial stability because bony ingrowth depends upon limited early micromotion. Tibial implant design fixation features resist micromotion aided by bony sidewall retention and interference fit. Our goal was to investigate factors influencing implant‐bone micromotion in TAR. Two TAR tibial components were virtually inserted into CT‐derived computer models of two distal tibias from patients with end‐stage ankle arthritis. Density‐based inhomogeneous material assignment was used to model bone compaction during press‐fit. Finite element analysis (FEA) was used to simulate three fixation cases: (1) no sidewalls + line‐to‐line fit, (2) sidewalls + line‐to‐line fit, and (3) sidewalls + 50, 100, or 200 µm interference fit. Kinetic profiles from the stance phase of gait were simulated and micromotions computed from FEA output. Without sidewalls or interference fit, micromotions were largest in early and late stance, with largest micromotions (averaging ~150–250 µm) observed near heel strike. Micromotions decreased 39%–62% when sidewalls were retained. When interference fit was also modeled, micromotions decreased another 37%–61% to ~10 µm. Micromotion differences between patients persisted with sidewall retention but largely disappeared with interference fit. This study presents new insights into the effects of TAR fixation features on implant‐bone micromotion. Stability appeared to be influenced by surrounding bone quality, but this influence was greatly diminished when interference fit was introduced. More complete understanding of TAR implant features and performance is needed, but our results show the importance of bone quality and interference fit in the stability of uncemented TAR. [ABSTRACT FROM AUTHOR]

Interference fit is an effective fatigue life reinforcing method for mechanical joints. The fatigue behaviors of interference fitted pinned joints with extremely small edge margin (Edge Distance Ratio, EDR < 1.5) were investigated via fatigue tests and numerical methods in this paper. The influences of pin insertion pre-stresses were focused. Crack initiation behaviors of both clearance fit and interference fit were characterized. Moreover, a practical approach was proposed to evaluate the full-field crack initiation life of joints, which is based on the stress outputs from FE model and the S-N (Stress versus Number of circles to failure) curve of the substrate material. Results showed that the interference fit exhibited an effective fatigue reinforcement for extremely small EDR. The fatigue crack initiation was dominated by the coupling effect of the interference size and the loading level. The fatigue crack initiated at the middle of the plate hole for clearance fit, while it started at the hole entrance side for interference fit. When the interference fit size increased, the crack initiation location moved from the hole edge toward the loading direction, while an opposite effect was observed for the increasing loading level. However, a high interference size could deteriorate the fatigue performance of the plate lateral face, which was prone to a secondary crack initiation. [ABSTRACT FROM AUTHOR]

Drive systems are an important part of general mechanical engineering, automotive engineering, and various other fields, with shaft–hub connections being an important part of such systems. Decisive aspects in the development of such systems today are, for example, high transmittable forces and torques, low masses, and the cheapest possible production of components. A possibly threefold increase in the force and torque transmission capacity can be achieved by using press–fit connections with an elastic–plastic design as opposed to regular elastically designed alternatives. An elastic–plastic design of the press–fit connection is achieved by using a large interference. A large transition geometry on the shaft (which replaces the conventional chamfer) is required to join such an interference. The material and space requirements have a negative impact on lightweight applications and limited building spaces. Therefore, the objective of the research presented in this paper is to design and analyze a detachable joining device that substitutes this geometry. A simulation study was conducted to determine the geometry of the joining device that improves the stress state and consequently the force and torque transmission capacity of the connection. Moreover, the influence of manufacturing tolerances of the joining device and the shaft, corresponding risks, and measures to mitigate them are analyzed using finite element analysis. The results show that large transition radii, enabled by using a joining device, lead to a homogenous distribution of plastic strain and pressure in the press–fit connection, even for large interferences ξ and soft hub materials like wrought aluminum alloys. The influence of manufacturing tolerances on the stress state was quantified, leading to design guidelines that minimize the risk of, e.g., the front face collision of a shaft and hub, while maximizing the power transmission of the connection. The results show the capability of a detachable joining device to enable elastic–plastic press–fit connections and the corresponding threefold increase in the force and torque transmission capacity in lightweight applications, resulting from the substitution of the installation space consuming and mass increasing the transition geometry of the shaft.

A novel dynamic installation (DI) method is proposed to improve the problems of severe installation damage, small installable interference size, and low installation efficiency of traditional static installation (SI) methods for installing interference bolts in composite bolted structures. The stress distribution and CFRP damage around the hole wall due to interference fitting and subsequent cyclic loading were predicted by finite element simulations. In addition, the fatigue life of DI and SI specimens was evaluated and the fatigue failure mechanisms were discussed. The results showed that the DI method provides a visible improvement in fatigue life, which is about 4 times that of the SI interference specimens and 38 times that of the non-interference specimen. In addition, DI introduces relatively higher average residual compressive stresses than SI, especially at the inlet of the laminate, which also results in a more uniform distribution along the axial direction of DI specimens. Micromorphological analysis of the specimens after fatigue failure indicated that the uniform stress distribution and low initial installation damage at the assembly interface introduced by the DI method during interference fit prevents severe delamination and crack propagation in joints subjected to external cyclic loading, such as the SI specimen. Severe extrusion deformation of the hole wall and matrix crushing are the main failure modes of DI specimens. Therefore, it is necessary to improve the interference installation method of composite materials. [ABSTRACT FROM AUTHOR]

Shaft sleeve assembly is a common task in industrial manufacturing. The fitting approach for shaft sleeve assembly is usually interference fit, which requires significant contact forces. Conventional assembly methods, though focused on safety, often struggle to achieve high efficiency. Reinforcement learning can effectively select appropriate assembly actions through interaction with the environment, making it well-suited for shaft sleeve assembly tasks. Firstly, a comprehensive workflow for shaft sleeve assembly is formulated, including system initialization, insertion, push, and completion. Our research focuses mainly on the insertion process. Secondly, the core control algorithm adopts a deep reinforcement learning method based on the Actor-Critic architecture. The reward function includes safety reward, step length reward, and step reward. Safety reward ensures assembly security, while step length and step reward enhance assembly efficiency from different perspectives. Finally, real-world experiments on shaft sleeve assembly are conducted, including ablation experiments, parameter tuning experiments on reward function, and comparative experiments with conventional methods. The results of the ablation experiments and parameter tuning experiments indicate that after combining safety reward, step length reward, and step reward, the assembly effect achieves the best, verifying the effectiveness of the proposed reward function. Comparative experimental results demonstrate that our approach not only enhances safety compared to conventional methods but also significantly improves assembly efficiency, indicating the feasibility of this method. [ABSTRACT FROM AUTHOR]

Hybrid bonded–bolted composite material interference connections significantly enhance the collaborative load-bearing capabilities of the adhesive layer and bolts, thus improving structural load-carrying capacity and fatigue life. So, these connections offer significant developmental potential and application prospects in aircraft structural assembly. However, interference causes damage to the adhesive layer and composite laminate around the holes, leading to issues with interface damage. In this study, we employed experimental and finite element methods. Initially, different interference-fit sizes were selected for bolt insertion to analyze the damage mechanism of the adhesive layer during interference-fit bolt installation. Subsequently, a finite element tensile model considering damage to the adhesive layer and composite laminate around the holes post-insertion was established. This study aimed to investigate damage in composite bonded–bolted hybrid joints, explore load-carrying rules and failure modes, and reveal the mechanisms of interference effects on structural damage and failure. The research results indicate that the finite element prediction model considering initial damage around the holes is more effective. As the interference-fit size increases, damage to the adhesive layer transitions from surface debonding to local cracking, while damage to the composite matrix shifts from slight compression failure to severe delamination and fiber-bending fracturing. The structural strength shows a trend of initially increasing and then decreasing, with the maximum strength observed at an interference-fit size of 1.1%. [ABSTRACT FROM AUTHOR]

Interference fits are widely used in aerospace, precision instruments and other fields. Press-fit assembly is one of the traditional assembly methods for interference fitting parts. Wear during assembly will affect the performance of interference components and the service life of marine equipment. Ultrasonic assisted press-fit can significantly reduce the press-mounting force of an interference fit. However, its effect on connection quality is rarely studied. The mechanism of ultrasonic assisted press-fit is unclear. In this paper, ultrasonic assisted press-fit was simulated and experimentally studied. The effects of ultrasonic vibration on heat generation, press-mounting force, connection strength, and interface wear were analyzed and discussed. Through analogy analysis with similar ultrasonic assisted machining processes, the mechanism of ultrasonic assisted press-fit was revealed. The results show that the superimposed ultrasonic vibration can effectively reduce the joining force (up to 33.5%), and increase the connection coefficient from 10% to 40%. This is due to stress superposition, friction reduction and acoustic softening that reduces interface wear. The increase of the interface roughness Rz from 3.681 to 4.586 μm confirms this analysis. Furthermore, the ultrasonic vibration can effectively reduce the material plastic flow of contact interface. This study reveals the significant advantages of ultrasonic assisted press-fit assembly (UAPA) method and provided a basis to understand the underlying mechanisms of UAPA. [ABSTRACT FROM AUTHOR]

An experimental test program was performed on grouted post-tensioned anchor rods to determine if anchors with high rod-to-duct area ratios could reanchor themselves upon fracture. Liftoff testing of the grouted anchors was also performed. Results of the study revealed the specimens were capable of reanchoring themselves over a short transfer length and possessed a significant amount residual bond strength following liftoff testing. A theoretical model was created to predict the transfer length phenomenon, which was founded on linear interference fit assumptions. The results between the physical tests and theoretical model demonstrated feasibility in the approach and assumptions. [ABSTRACT FROM AUTHOR]

In this research paper, interference fit was studied in order to verify the change in the thickness of the models used, as well as the value of the interference fit ratio, and to study its effect on the fatigue phenomenon. Three variables were taken for the thickness of the board: 2, 4, and 6 mm, and three ratios of interference fit: 1.5, 2.4, and 4.7, to see its effect on the phenomenon of fatigue. As the results showed, high pressure is required for the process to pass the pin inside the hole. The deformation value increases with the thickness of the sample. The ANSYS program was used for the purpose of simulation. High pressure is required for the pin to pass inside the hole. The deformation value increases with the thickness of the sample. The highest stress value is 0.063mm, which is the highest value compared to other solutions. It is necessary to obtain results that represent the trajectory on the three axes of the mouth of the pin. The interference fit's pressures and deformations must be used to get findings that depict the route along the mouth's three axes. Changes in the route indicated by the edge of the sample along its length to the center of the pin result in x-axis deformations; it is evident that when the interference fit becomes tighter, the deformation value also rises. In the scenario where the ratio fits 4.7%, deformation has reached 0.1mm, which is the largest amount compared to other instances. The maximum stress value of any known solution is 3.7 GPa. The value of the stresses on the y axis varies throughout the track and rises at the second-third of the axis track length. The deformation value in the situation when the ratio fits 4.7 percent has reached 0.27mm, which is the largest value. [ABSTRACT FROM AUTHOR]

Objective Aiming at the problem that the assembly quality of interference fit components is difficult to control, a method for monitoring the assembly quality of such components based on digital twin technology is proposed.Methods Combined with digital twin technology, the framework of an assembly quality monitoring system for interference fit components is constructed; the actual assembly process is comprehensively analyzed and a real-time monitoring process of the assembly process based on the press-fitting force is designed; and a state prediction model of the press-fitting force based on the Markov model is established, and a comprehensive judgment of the assembly quality of the interference fit components is realized by the comprehensive comparison of theoretical press-fitting force, actual press-fitting force and press-fitting force prediction state.Results The interference fit between the output shaft and sun gear of a typical marine planetary reducer is used as an example for verification. The results show that this method can realize the real-time collection and monitoring of the press-fitting force at key points in the assembly process and predict the future quality characteristics of the point. At the same time, the experimental results of the physical assembly platform are compared with the model prediction results, and it is found that the two are consistent, which proves that the proposed method of monitoring the assembly quality of interference fit components based on digital twin technology is effective and feasible.ConclusionThe results of this study have important reference significance for the realization of quality monitoring in the process of the intelligent assembly of mechanical products.

Spindle bearing fits mainly include interference fit of inner ring and clearance fit of outer ring, which directly affect the vibration characteristics of spindle rotor-bearing system. In this paper, the influence of spindle bearing inner and outer ring fits on bearing support stiffness is firstly studied. Considering the spindle bearing inner and outer ring fits, a dynamic model of spindle rotor-bearing system is established. Then, the analysis methods of bifurcation and time domain are used to perform simulation analysis. The influence of bearing fit on the vibration characteristics of rotor system is researched. Lastly, at different rotating speeds, bearing fits experiments are conducted on built motorized spindle test platform, which verifies the correctness of the dynamic model. The results show that the influence of bearing fit on vibration is nonlinear. The influence of clearance fit on vibration is smaller, when the clearance fit value of bearing outer ring is about 4-6 μm. The vibration characteristics of rotor are more sensitive to the clearance fit of bearing outer ring than the interference fit of bearing inner ring. The research work provides an important theoretical basis for the optimal of spindle bearing assembly. [ABSTRACT FROM AUTHOR]

The behavior of the lug joint with interference-fit fastener subjected to axial load which represents a moving boundary value problem is addressed in the article. The variation of contact stresses between the pin and the lug-hole is non-linear and is studied by partially linearizing the non-equilibrium equations. The inverse formulation is employed to estimate the loss of contact of the pin from the lug hole. The operating load levels corresponding to these pin separation regions determine the critical locations of high-stress fields. The lug-hole is pre-stressed by the cold-working which creates the plastic wake around the lug-hole periphery and reduces the stress levels which is beneficial in the retardation of crack growth at critical locations and enhances the performance of the lug joint. Three-dimensional numerical analysis is performed wherein the novel and effective approach in performing the cold-working of lug-hole, insertion of the interference-fit pin and applying pin load is defined in displacement-controlled time steps. The loss of contact of the pin and the cycles to failure is computed using an in-house Python script. The methodology and findings assist in forecasting failure and can be used as a reference for similar fastener problems in engineering applications. [ABSTRACT FROM AUTHOR]

In the long-distance pigging operation of natural gas pipelines, severe wear of the sealing cups always leads to the failure and instability of the pig. Different from ordinary conditions, the wear process of the polyurethane rubber (PUR) used in the pigging operation occurs under the condition of interference fit, which generates a continuously varied wear rate. In this research, a custom-built wear experiment was designed and conducted by adopting a specially made indenter and specimen, and then the effect of contact pressure on the wear rate, i.e., the empirical expression of wear rate, was obtained based on the test results and Hertz contact theory. In addition, a numerical model that presents the PUR interference wear behaviors was established by combining the empirical expression of the wear rate and the analytical expression of the hyperelastic materials under the interference fitting. Through MATLAB programming with the iterative algorithm, the wear laws of two kinds of sealing cups were investigated, and the results indicate a coupling induction among the wear rate, wear loss, and contact pressure. The variation of wear loss with traveling distance was proven to agree with the exponential function, and thus a prediction model suitable for engineering practice was built to calculate the wear loss of the sealing cups. [ABSTRACT FROM AUTHOR]

The research on how to reduce energy consumption and improve the efficiency of amorphous motors has extensive coverage. This study systematically investigates the influence of internal stress induced by impregnation curing and interference fit on the soft magnetic properties and loss characteristics of Fe80Co3Si3B10P1C3 (CAF4) amorphous alloy iron cores. The amorphous iron core samples undergo analysis through differential scanning calorimetry (DSC), transmission electron microscopy (TEM), X-ray diffraction (XRD), magnetic performance testing equipment, flexible pressure sensors, and magnetostriction testers. The CAF4 amorphous iron core after impregnation curing (AIC) exhibits the lowest loss of P1.2T,1.5 kHz = 22.8 W/kg when annealed at 260 °C, representing a 21% increase compared to the pre-impregnation curing (BIC) state. Within the commonly utilized interference fit range, the loss growth rate of CAF4 amorphous iron cores is lower than that of Fe80Si9B11 (1K101). Likewise, at a frequency of 50 Hz and an excitation of 1000 A/m, the magnetostriction coefficient of CAF4 is smaller than that of 1K101. Within the typical interference fit range, the magnetization performance of CAF4 amorphous iron cores surpasses that of 1K101, favoring lightweight and compact motor designs and reducing copper losses. Consequently, CAF4 amorphous iron cores exhibit significant advantages when employed in motors. [ABSTRACT FROM AUTHOR]

A high-speed permanent magnet motor is the core driving component of a centrifugal air compressor. The power of the centrifugal air compressor is output by the motor. Its safety and reliability are embodied in the stability of the rotor structure, which greatly affects the stability and working efficiency of the centrifugal air compressor. Much research has focused on the material strength, structural characteristics, and fit clearance of a high-speed rotor, whereas few research articles have focused on the influence of interference fit of high-speed and ultra-high-speed permanent magnet motors, and there is also little research on the thermal failure caused by temperature in high-speed motors. In this paper, the influence of the interference fit and temperature of the high-speed permanent magnet motor is studied. Using finite element analysis conducted by Ansys to obtain simulation data, the influencing factors of the strength of the interference are analyzed comprehensively in the centrifugal compressor rotor system. The interference value and rotational speed range are determined via numerical calculation. Under the condition of minimum interference, when the calculated speed reaches 137,628.82 rpm, the structure of the rotor is loose and fails, which is a mechanical failure caused by the relative sliding of the magnet and the sheath. The calculated speed value differs from the simulation result by about 1.2%. The simulation results show that the maximum stress of the structure can be reduced from 1186.1 MPa to 308.42 MPa by adding chamfer to the end covers in interference fit structure. The effects of interference value, rotational speed, temperature, and sheath thickness on the structure are also analyzed. From the perspective of temperature on structural reliability, the failure temperature of the structure decreases when the interference value increases. The lowest failure temperature is 182.3 °C when the interference value is 70 μm. After that, the interference value increases and the failure temperature increases. The reason for this is the interaction between radial stress and contact stress. These results are caused by the interaction between interference fit and temperature, which should be paid attention to when the structure of a high-speed permanent magnet motor is designed. [ABSTRACT FROM AUTHOR]

Mechanical couplings in engineering usually use interference fits to connect the shaft and hub. A railway wheel axle is a press fit that is connected by interference and can be subjected to bending stress. In loaded press fits, a high concentration of contact stresses can be generated in the area of the axle-fillet beam, which in most cases leads to the failure of the axle due to fatigue and fretting fatigues. Therefore, it is crucial to determine the ability of the press-fitted joints to provide sufficient frictional resistance that can withstand the loads and torques by evaluating the safety factor, especially when the mechanical or structural system is loaded. In this paper, the contact pressure and stress distribution along the radius of the wheel axle are studied using the analytical calculation of Lame's equation, and the numerical method used is by ANSYS software. It was found that interference fits have a great influence on the connection strength of interference fits, which are directly related to the contact pressure. Increasing the interference increases the contact pressure, which allows higher torque and load capacity to be transmitted. The finite element analysis showed good agreement for the highest interference value of 230 µm with a relative error of 1.4%, while this error increased to the maximum relative error of 14.33% for a minimum interference of 100 µm. [ABSTRACT FROM AUTHOR]

Abstract After remanufacturing disassembly, several kinds of friction damages can be found on the mating surface of interference fit. These damages should be repaired and the cost is closely related to the severity of damages. Inspired by the excellent performance of surface texture in wear reduction, 5 shapes of pit array textures are added to the specimens’ surface to study their reduction effect of disassembly damage for interference fit. The results of disassembly experiments show that the order of influence of texture parameters on disassembly damage is as follows: equivalent circle diameter of single texture, texture shape and texture surface density. The influence of equivalent circle diameter of single texture and texture shape are obviously more significant than that of texture surface density. The circular texture with a surface density of 30% and a diameter of 100 μm shows an excellent disassembly damage reduction effect because of its perfect ability of abrasive particle collection. And the probability of disassembly damage formation and evolution is also relatively small on this kind of textured surface. Besides, the load-carrying capacity of interference fit with the excellent texture is confirmed by load-carrying capacity experiments. The results show that the load-carrying capacity of the excellent texture surface is increased about 40% compared with that of without texture. This research provides a potential approach to reduce disassembly damage for interference fit.

This paper aims to study the crashworthiness of shrink tubes for rail vehicles under axial impact loading. A theoretical model of shrink tube for platform force prediction under interference fit conditions was proposed. The trolley crash test was used to experimentally study the structural energy absorption and characteristics during collision, and a corresponding finite element model was constructed and validated. The finite element model validated the accuracy of the theoretical model. The influence of structural parameters on the crashworthiness of shrink tube under interference conditions was then studied. Structural design variables, including the magnitude of interference (int_pre), thickness (T), long right-angle edge (tri_x) and short right-angle edge (tri_z) were sampled using a full factorial and a Latin hypercube design method. Based on the above samples, the moving least squares method (MLSM) was used to construct an approximate model of peak force (Fmax), specific energy absorption (SEA), and platform force (Fplt). The main effects analysis illustrated that the tri_z had the most significant effects on the peak force, specific energy absorption and platform force. To minimize Fmax and maximize SEA, the global response surface method (GRSM) was employed for parameter optimization. Finally, the optimized configurations were obtained with int_pre=0.067mm, T=10.003mm, tri_x=21.485mm, and tri_z=6.101mm. Compared to the initial design, the SEA value was increased by 16.41 %, while the Fmax value was decreased by 2.21%. The error of platform force derived from the optimal solution and theoretical prediction was 3.62%, which verified that the theoretical prediction model was credible within an acceptable range.

Remanufacturing has been gaining increasing attention in the last few years as a part of green engineering. It is the process of restoring the original specifications of a given product utilizing a combination of new, repaired, and old parts. The present study investigates non-destructive disassembly of an interference fit pin-hub joint to enable the reuse of worn parts with the same loading capacity. The aim is to reduce the disassembly force while preventing plastic deformation and frictional damage on the contact surface to avoid fretting failure and enable further coating. A finite element model of a shaft/hub interference fit was developed, taking into account two cases of damage to the mating parts: deformation and corrosion. The results indicate that thermal disassembly is effective in reducing breaking force by 50% in deformed joints, whereas vibration waves are more suitable for corroded parts with increased friction. In addition, applying a low-frequency oscillation force to the axis of disassembly reduces the pulling out force by 5% and plastic deformation by 99% due to acoustic softening effects. Furthermore, using a heat flux simultaneously with vibration decreases the breaking force by 85%, indicating the higher effectiveness of thermal-aided disassembly and vibration-assisted disassembly in reducing the breaking force of corroded parts with increased friction. This study provides remanufacturing designers with efficient tools to weaken the interference fit and decrease the disconnecting force, ultimately reducing the cost and time required for the disassembly process. [ABSTRACT FROM AUTHOR]

After remanufacturing disassembly, several kinds of friction damages can be found on the mating surface of interference fit. These damages should be repaired and the cost is closely related to the severity of damages. Inspired by the excellent performance of surface texture in wear reduction, 5 shapes of pit array textures are added to the specimens' surface to study their reduction effect of disassembly damage for interference fit. The results of disassembly experiments show that the order of influence of texture parameters on disassembly damage is as follows: equivalent circle diameter of single texture, texture shape and texture surface density. The influence of equivalent circle diameter of single texture and texture shape are obviously more significant than that of texture surface density. The circular texture with a surface density of 30% and a diameter of 100 μm shows an excellent disassembly damage reduction effect because of its perfect ability of abrasive particle collection. And the probability of disassembly damage formation and evolution is also relatively small on this kind of textured surface. Besides, the load-carrying capacity of interference fit with the excellent texture is confirmed by load-carrying capacity experiments. The results show that the load-carrying capacity of the excellent texture surface is increased about 40% compared with that of without texture. This research provides a potential approach to reduce disassembly damage for interference fit. [ABSTRACT FROM AUTHOR]

The long-term success of cementless surgery strongly depends on the implant primary stability. The femoral stem initial fixation relies on multiple geometrical and material factors, but their influence on the biomechanical phenomena occurring during the implant insertion is still poorly understood, as they are difficult to quantify in vivo. The aim of the present study is to evaluate the relationship between the resonance frequencies of the bone–implant–ancillary system and the stability of the femoral stem under various biomechanical environments. The interference fit IF, the trabecular bone Young's modulus E t and the bone–implant contact friction coefficient μ are varied to investigate their influence on the implant insertion phenomena and on the system vibration behavior. The results exhibit for all the configurations, a nonlinear increase in the bone–implant contact throughout femoral stem insertion, until the proximal contact is reached. While the pull-out force increases with E t , IF and μ , the bone–implant contact ratio decreases, which shows that a compromise on the set of parameters could be found in order to achieve the largest bone–implant contact while maintaining sufficient pull-out force. The modal analysis on the range [2-7] kHz shows that the resonance frequencies of the bone–implant–ancillary system increase with the bone–implant contact ratio and the trabecular bone Young's modulus, with a sensitivity that varies over the modes. Both the pull-out forces and the vibration behavior are consistent with previous experimental studies. This study demonstrates the potential of using vibration methods to guide the surgeons for optimizing implant stability in various patients and surgical configurations. [ABSTRACT FROM AUTHOR]

Studies on load capacity enhancement for an interference fit mainly focused on the essential coupling material pair of steel–steel parts. With more complex requirements in technical assemblies, more notable cases of material pairs are applied in interference fits. Hence, it is crucial to highlight the variations across-coupling scenarios in order to identify a workable approach for load capacity augmentation. The goal of this study is to examine how nickel plating affects the interference fit between steel and brass assembly parts. The experiments in this research focus on comparing the load capacity of plated and non-plated specimens by evaluating the extraction force on a compression machine. The fit parameters are measured with a coordinate measuring machine and contact surface profiler. Some microscopic observations are made to confirm the phenomena of this coupling case. The axial extraction tests determined that the plated fits show an increase in axial force limits of around 20% in comparison with the non-plated ones. There are also some significant improvements in the plated shaft surface properties, which reduce the physical adhesions between the shaft and hub. These results confirm the possibility of reusing the plated assembly parts, which gives highly economic and environmental advantages. [ABSTRACT FROM AUTHOR]

The interference fit has been widely used for torque transmission and assembly stability in the modern machinery industry. The form error of cylindrical feature is propagated during the interference fit of shaft-hole assembly, which causes the translation and rotation of following structures. Therefore, the overall precision variation is difficult to be predicted. In this paper, an error computational model of interference fit stage is proposed to represent the form error propagation of cylindrical features in the shaft-hole assembly. The characteristic parameter of form error is obtained by the minimum zone cylinder method and integrated into the small displacement torsor. The deformation behavior of interference fit with form error is described as a weakening propagation of error. An interference fit error propagation coefficient is introduced to quantify the phenomenon of weakening propagation of error, which depends on particular fit conditions such as materials, sizes, and interference range of parts. The error computational model for interference fit with form feature is deduced by using the Jacobian-Torsor theory. The characteristic of deformation flexibility in the interference fit is well considered comparing to the simple rigidity analysis in the traditional Jacobian-Torsor model. An error analysis of a shaft-hole structure deciding the symmetry and sensibility performance in the servo valve is conducted to verify the applicability. The cylindrical feature error and deformation during the interference fit are included. The results show that the new error model may represent characteristics of interference fit error propagation with form feature and has a higher reliability than the traditional error models. [ABSTRACT FROM AUTHOR]

Based on the thick-wall cylinder theory and composite material mechanics, the stress distribution model of the CFRP shaft tube and metal shaft head has been established, and the relationship between the layup parameters and the value of interference on the maximum assembly force and failure torque in the interference fit joints of the CFRP shaft tube and the metal shaft head is deduced. Combining the three-dimensional finite element analysis model with experimental data, the result shows that the layup angles of the CFRP shaft tube have a greater influence on the joint connection performance than the layup sequence, and the larger the layup angle, the better the joint assembly performance while keeping the value of interference constant. The maximum assembly force and failure torque of the interference fit joints increase linearly while the value of the interference amount increases when the layup parameters are constant.

• Internal damping effects due to interface resulting in rotordynamic instability. • Novel linear model combining a GW contact with the Yoshimura damping models. • Instability onset speed (IOS) change for contact number, preload, Brg. Dyn. Coeff. • Validation of the predicted IOS with Jafri Single-Disk test with interference fits. Rotating machinery shafting is typically comprised of multiple components that are assembled to ensure reliable operation, proper alignment minimal vibration. However, conventional rotordynamics approximates the shafting as a single, continuous member, neglecting contact interfaces between the components. The presence of an interface can induce microslip, which generates internal friction that may cause instability and machinery failure. A novel approach of modeling the interface viscous damping effect on rotordynamics is proposed by combining a GW (Greenwood and Williamson) contact model with the Yoshimura damping model. All structural components are modeled using 3D solid finite elements. Modal damping ratio is utilized to identify the instability onset speed (IOS). The results show that internal friction has a destabilizing effect on whirl motion above the first critical speed, but has a stabilizing effect on the motion below the first critical speed. The destabilizing effect can be reduced by increasing the bearing damping, however excessive bearing damping can drive the effective damping towards negative values. Increasing the number of interfaces reduces stability while increasing an interface preload prevents microslip, and increases stability. Lastly, smoother surfaces at the interfaces increase the IOS. [ABSTRACT FROM AUTHOR]

• A typical composite failure of an inter-shaft bearing inner ring is reported. • The failure root cause and mechanism of the fractured bearing inner ring is proposed. • Numerical simulations are performed considering multi-physical loads and failure time sequence. • Reasonable improvement measures to avoid this type of composite failure are proposed. The inter-shaft bearing is a critical component in dual rotors aero-engine. Due to the complex and severe loads caused by the interactive excitation of HP and LP rotors during operation, the inter-shaft bearing is prone to damage accumulation and failure. Focusing on a typical failure of inter-shaft bearing inner ring fragmentation and cannot be spliced together completely in high thrust-weight ratio turbofan engine, this paper conducted morphological investigation, fractographic analysis, vibration signal processing, finite element numerical simulation, and fully studied the failure mechanism of this failure. The results indicated that: there exists an uncoordinated resonance speed of the HP rotor in close proximity to the operating speed. This puts the rotor in non-synchronous procession state, accompanied by the uncoordinated angular displacement of the inner and outer rings, which resulting in a lager rolling dynamic load in bearing inner ring. This further leads to high tangential impact load at the root fillet of the anti-rotation pin, causing significant stress concentration, and eventually leads to the generation of initial cracks. These cracks persist and propagate into fatigue oblique fracture over time. After oblique fracture, the modal frequencies of the inner ring become more dispersed. Under the rolling dynamic load (traveling wave load), nodal diameter vibration occurs, causing high stress vibration fatigue damage, and ultimately leading to multiple-point simultaneous fragmentation. The investigation suggests that reducing the stress levels at the root fillet of the anti-rotation pin of the inner ring is an effective approach to prevent bearing failure. This can be achieved through two methods: one is optimizing the rotor structure to decrease the rolling dynamic load on the inner ring, the other is eliminating the anti-rotation pin and appropriately reducing the tightening torque of the compression nut and the interference between the bearing inner ring and the HP turbine rear journal. [ABSTRACT FROM AUTHOR]

• The evolution mechanisms of out-of-plane performance in C/SiC riveted joint are demonstrated. • The refined simulation model considering deposited SiC matrix, mesoscale structural characteristics and interference fit is established. • The thermos-mechanical coupling effects on failure mechanisms of C/SiC riveted joints are illustrated by experiments and simulations. • Significant factors affecting jointed performance including deposition of SiC matrix and interference fit are revealed. The failure mechanisms of C/SiC riveted joints are complicated and unclear under thermo-mechanical coupling loading. This work numerically and experimentally examines the mechanical responses, failure evolutions and damage modes of C/SiC riveted joints subjected to push-out loading at room temperature and 800 ℃. The typical C/SiC riveted joints are fabricated by integrated manufacturing techniques based on CVI process, which are then adopted for push-out experiments through the combined mechanical and thermal loading system. To fully reveal the thermo-mechanical coupling damage mechanisms, a refined finite element (FE) model is established, considering deposited SiC matrix, structural characteristics of C/SiC composites and interference fit. The comprehensive results from FE model and experiments indicate the bearing capacity of C/SiC riveted joints could maintain within a certain deformation range even under broken interface between rivet and plate, which benefits from the designed interference fit. Furthermore, significant temperature-dependent mechanical responses and damage modes are observed and analyzed. This work could potentially provide the basis for designing reliable hot structures made of ceramic matrix composite. [ABSTRACT FROM AUTHOR]

An experimental program was conducted that simulated an internal rod failure to review re-anchoring ability, transfer length, and residual bond strength of grouted post-tension anchors with high rod to duct area ratios under in-situ conditions. Additionally, a theoretical model founded on interference fit, initial assumptions, and debris wedging was expanded to include a concrete to pipe interface. The experimental program included three full scale concrete specimens, whose length, annulus space for grout, and anchor diameter were nearly identical to existing anchors within dams in California. The specimens were instrumented along the anchor and concrete to capture strains in the longitudinal and transverse directions, the values of which, were compared against the theoretical model and found to be in good agreement along with the measured transfer length values. The debris wedging ratio found was consistent across the specimens and closely resembles the ratio captured in a similar study by the authors. • Consideration of initial conditions for re-anchoring of grouted post-tension anchors. • Proposed input / consideration of debris wedging. • Interference fit calculation procedure for a multilayer anchorage system. • Experimental comparison with theoretical model for cleaned and uncleaned specimens. [ABSTRACT FROM AUTHOR]

The research on how to reduce energy consumption and improve the efficiency of amorphous motors has extensive coverage. This study systematically investigates the influence of internal stress induced by impregnation curing and interference fit on the soft magnetic properties and loss characteristics of Fe80Co3Si3B10P1C3 (CAF4) amorphous alloy iron cores. The amorphous iron core samples undergo analysis through differential scanning calorimetry (DSC), transmission electron microscopy (TEM), X-ray diffraction (XRD), magnetic performance testing equipment, flexible pressure sensors, and magnetostriction testers. The CAF4 amorphous iron core after impregnation curing (AIC) exhibits the lowest loss of P1.2T,1.5 kHz = 22.8 W/kg when annealed at 260 °C, representing a 21% increase compared to the pre-impregnation curing (BIC) state. Within the commonly utilized interference fit range, the loss growth rate of CAF4 amorphous iron cores is lower than that of Fe80Si9B11 (1K101). Likewise, at a frequency of 50 Hz and an excitation of 1000 A/m, the magnetostriction coefficient of CAF4 is smaller than that of 1K101. Within the typical interference fit range, the magnetization performance of CAF4 amorphous iron cores surpasses that of 1K101, favoring lightweight and compact motor designs and reducing copper losses. Consequently, CAF4 amorphous iron cores exhibit significant advantages when employed in motors.

A high-speed permanent magnet motor is the core driving component of a centrifugal air compressor. The power of the centrifugal air compressor is output by the motor. Its safety and reliability are embodied in the stability of the rotor structure, which greatly affects the stability and working efficiency of the centrifugal air compressor. Much research has focused on the material strength, structural characteristics, and fit clearance of a high-speed rotor, whereas few research articles have focused on the influence of interference fit of high-speed and ultra-high-speed permanent magnet motors, and there is also little research on the thermal failure caused by temperature in high-speed motors. In this paper, the influence of the interference fit and temperature of the high-speed permanent magnet motor is studied. Using finite element analysis conducted by Ansys to obtain simulation data, the influencing factors of the strength of the interference are analyzed comprehensively in the centrifugal compressor rotor system. The interference value and rotational speed range are determined via numerical calculation. Under the condition of minimum interference, when the calculated speed reaches 137,628.82 rpm, the structure of the rotor is loose and fails, which is a mechanical failure caused by the relative sliding of the magnet and the sheath. The calculated speed value differs from the simulation result by about 1.2%. The simulation results show that the maximum stress of the structure can be reduced from 1186.1 MPa to 308.42 MPa by adding chamfer to the end covers in interference fit structure. The effects of interference value, rotational speed, temperature, and sheath thickness on the structure are also analyzed. From the perspective of temperature on structural reliability, the failure temperature of the structure decreases when the interference value increases. The lowest failure temperature is 182.3 °C when the interference value is 70 μm. After that, the interference value increases and the failure temperature increases. The reason for this is the interaction between radial stress and contact stress. These results are caused by the interaction between interference fit and temperature, which should be paid attention to when the structure of a high-speed permanent magnet motor is designed.

Mechanical couplings in engineering usually use interference fits to connect the shaft and hub. A railway wheel axle is a press fit that is connected by interference and can be subjected to bending stress. In loaded press fits, a high concentration of contact stresses can be generated in the area of the axle-fillet beam, which in most cases leads to the failure of the axle due to fatigue and fretting fatigues. Therefore, it is crucial to determine the ability of the press-fitted joints to provide sufficient frictional resistance that can withstand the loads and torques by evaluating the safety factor, especially when the mechanical or structural system is loaded. In this paper, the contact pressure and stress distribution along the radius of the wheel axle are studied using the analytical calculation of Lame’s equation, and the numerical method used is by ANSYS software. It was found that interference fits have a great influence on the connection strength of interference fits, which are directly related to the contact pressure. Increasing the interference increases the contact pressure, which allows higher torque and load capacity to be transmitted. The finite element analysis showed good agreement for the highest interference value of 230 µm with a relative error of 1.4%, while this error increased to the maximum relative error of 14.33% for a minimum interference of 100 µm.

Cylindrical keyed joint fits used in various assembly units of industrial machinery and agricultural machines have been considered. In most cases, these are clearance, less often, transitional fits due to the assembly and disassembly velocity criterion in this type of connection. In the clearance fits, wear occurs due to the initial relative surface movements, as well as abrasive and wear products occurring in the friction zone. The larger the clearance, the smaller the contact area, the higher the specific pressure, the greater the microshear velocity, the greater the number of contaminants in the contact zone, and the more intensive the surface wear. If there is clearance in the cylindrical fit, the key begins to move along the horizontal and vertical planes, thus leading to increased surface wear and crushing in the key connection with the shaft groove and the bushing groove. Given that the purpose of keyed joints in agricultural machinery is the transmission of large loads, it is recommended to use an interference fit of H7/s7, H8/х8, H8/u8, and H8/s8 to improve the durability substantially. The recommended interference fits have been compared in terms of the interference values in the sprocket shaft joint of the unified reducer H090.20, where 30H7/h9 was earlier used. Even with the highest interference fits, it is possible to dismantle the pressed cylindrical connection using manual pullers. [ABSTRACT FROM AUTHOR]

During cementless total knee arthroplasty (TKA), an overlap between the resected tibia and the implant's geometry, termed interference fit, is introduced to facilitate primary stability and direct bone-implant contact. However, little is known about the actual interference achieved and the resulting mechanical response in the surrounding cancellous bone. The aim of this study was (1) to experimentally quantify the actual interference achieved for a commercially available cementless tibial implant and (2) to assess its effect on the post-impaction cancellous bone strain. Seven human cadaveric tibiae were micro-CT scanned intact (23 µm/pixel), once prepared for TKA (46 µm/pixel) and following implantation (46 µm/pixel). The actual interference across the entire bone-implant interface was quantified and, via digital volume correlation, the compressive strains of bone in contact with the implant and at increasing distance, were extracted. An inhomogeneous actual interference was found across the implant pegs and keel (median ± std dev: 0.70 ± 0.27 mm), which was lower than the intended. Limited interference (0.02 ± 0.12 mm) was found directly under the baseplate, with immediate bone-baseplate contact of 54%. The induced compressive strains were related to the actual interference within 3.14 mm from the bone-implant interface (R 2  = 0.269-0.450, p < 0.001), with higher compressive strains corresponding to higher interference, but not being related to the bone volume fraction. Clinical Significance: Insight is provided into the interaction between the variability of the resection and the resulting mechanical environment. A complex relationship is apparent, whereby the actual interference accounted for up to 45% of the variation in induced compressive strain magnitude., (© 2024 Orthopaedic Research Society.)

Interference fits are generally used in mechanical systems because they have low-cost production and their assembly parts are much smaller than other mechanical joints. Also, their geometric shapes and material properties allow technicians to actively determine how strong the fits are. In this study, let's present research on interference fits between steel and brass assembly parts. The experimental processes were accomplished with five pairs of specimens to evaluate the behaviours of surface asperities under a high loading condition. Specifically, the specimen pair includes a C45 steel shaft and a C2680 brass hub, which have different surface roughness values (Ra). Let's apply high-precision methods in measuring all dimensional parameters and employed axial load tests for distinctively inspecting the steel-brass interference fit performance. In every experiment, the measured responses are: 1) the surface roughness values (Ra) before and after loading cycles; 2) the axial load (Fa); 3) the relative displacement value or the real-time interface length in loading stages (l). The aim of this study is to propose a new relative interference value specifically between steel and brass assembly parts, which can help determine the interference loss value more accurately. It was concluded that with the relative interference of 2.25 ‰ the load capability of steel-brass interference fits is extended. Besides, let's narrow down the predictive loss coefficient (a) for steelbrass interference assemblies ranging from 1.1 to 2.1, which varies from widely used standards considering α = 3. This result helps minimize inaccuracies in interference fit designs, calculations, and work capabilities. [ABSTRACT FROM AUTHOR]

This article focuses on solving the problem of precise peg-in-hole assembly. The main contribution of this article is to propose a control method to improve the assembly precision. The method is capable to realize the precise insertion assembly tasks of cylindrical or prismatic objects with clearance or interference fit. In this article, a feature space and a response space are first constructed according to the relative pose and equivalent forces and moments. Then, the contact states are segmented in the feature space and the segmentation boundaries are mapped into the response space. Furthermore, a feature-based compliance control (FBCC) method is proposed based on boundary mapping. In FBCC method, a direction matrix is designed to execute accurate adjustment and an integral element is applied to eliminate residual responses. Finally, the simulations and experiments demonstrate the superiority and robustness of FBCC method. [ABSTRACT FROM AUTHOR]

A device is proposed for determining the pressure in a joint based on an interference fit. Its sensitive element consists of balls located between the contacting surfaces. Two types of contact interaction between the balls and the components of the joint are considered: elastoplastic deformation of the balls; and elastoplastic deformation of the parts. The pressure in shaft–bush contact is determined from the deformation. [ABSTRACT FROM AUTHOR]

Gears mounted on a shaft via interference fit are the subject of an internal pressure which is essential for power transmission between gear and shaft. The pressure between shaft and gear is responsible for additional stresses occurring both in shaft and gear. This study examines the effect of stresses arising due to the interference on the crack growth that exists at the root of the gear tooth. The numerical analyses were conducted on models having different rim thicknesses by using the extended finite element method that allows mesh-independent crack modeling and does not need re-meshing. The results showed that internal pressure yields additional stresses in the tangential direction. The increment in tangential stress changed the location and intensity of the maximal 1st principal stress and accelerated crack growth. As the tightness of the fit increased, the crack turned towards the rim rather than towards the tooth. As the crack growth through the rim may cause a catastrophic failure of gear, the increment in tangential stress due to internal pressure is crucial for the fatigue life of the gear. [ABSTRACT FROM AUTHOR]

• Considering the disc-shaft nonlinear contact, the finite element model of rotor system is established. • Newmark-β and Newton-Raphson methods are used to solve the dynamic response. • The established dynamic model considers the variation of disc-shaft contact state. Typically, the interference fit is used to perform the tight junction between disc and shaft. Nevertheless, the nonlinear contact between disc-shaft is neglected in tradition research. Hence, aimed at the shortcoming, considering the nonlinear contact between disc-shaft, the finite element model of rotor system featured with coupling parallel misalignment is established based on Timoshenko beam theory. Firstly, due to the nonlinear of disc-shaft contact, Newmark-β method is employed to combine Newton-Raphson method to solve the dynamic response. Then, according to the comparative analysis between dynamic characteristics of rotor systems operated with three conditions, the concretely discussion on the effect of initial interference and parallel misalignment degree are performed. The results show that disc-shaft nonlinear contact can cause the slight collision between disc-shaft, and the existence of parallel misalignment can intensify the slight collision. Besides, as rotation speed up, the contact states between disc-shaft become the process of repeated cycles: separation, contact, and then separation. Finally, the experiment study is conducted, and the concluded that the experiment result is corresponding to the simulation result can be obtained. It is established that the research results can provide possibilities for the identification and diagnosis of the rotor system with disc-shaft nonlinear contact. [ABSTRACT FROM AUTHOR]

Remanufacturing has been gaining increasing attention in the last few years as a part of green engineering. It is the process of restoring the original specifications of a given product utilizing a combination of new, repaired, and old parts. The present study investigates non-destructive disassembly of an interference fit pin-hub joint to enable the reuse of worn parts with the same loading capacity. The aim is to reduce the disassembly force while preventing plastic deformation and frictional damage on the contact surface to avoid fretting failure and enable further coating. A finite element model of a shaft/hub interference fit was developed, taking into account two cases of damage to the mating parts: deformation and corrosion. The results indicate that thermal disassembly is effective in reducing breaking force by 50% in deformed joints, whereas vibration waves are more suitable for corroded parts with increased friction. In addition, applying a low-frequency oscillation force to the axis of disassembly reduces the pulling out force by 5% and plastic deformation by 99% due to acoustic softening effects. Furthermore, using a heat flux simultaneously with vibration decreases the breaking force by 85%, indicating the higher effectiveness of thermal-aided disassembly and vibration-assisted disassembly in reducing the breaking force of corroded parts with increased friction. This study provides remanufacturing designers with efficient tools to weaken the interference fit and decrease the disconnecting force, ultimately reducing the cost and time required for the disassembly process.

Fretting fatigue is a fatigue damage process that occurs when two surfaces in contact with each other are subjected to relative micro-slip, causing a reduced fatigue life with respect to the plain fatigue case. Fretting has now been studied deeply for over 50 years, but still no univocal design approach has been universally accepted. This review presents a literature study that involves the three main types of mechanical joint affected by fretting fatigue (press-fitted shaft hub joints, dovetail joints, and bolted joints) aiming at giving insight into the progress made in terms of design guidelines for engineers. [ABSTRACT FROM AUTHOR]