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Copyright of Chinese Journal of Applied Mechanics is the property of Chinese Journal of Applied Mechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As an important component of the crawler walking device, the track roller needs to withstand strong impact and is prone to failure, which can lead to serious economic losses. This paper focuses on the track roller of the spreader as the research subject and investigates the dynamic contact characteristics between the track roller and the track plate. Using RecurDyn software, a virtual prototype model of the crawler walking device is established to analyze the variation in a vertical dynamic load of the track roller under different working conditions. Simultaneously, a finite element model of the contact between the track roller and the track plate is developed using Ansys Workbench, and its accuracy is verified using Hertz contact theory. Finally, the study discusses various influencing factors on the contact characteristics, including load, curvature of the contacting bodies, and material yield strength. The results indicate that the track rollers experience the highest dynamic load when climbing a slope, reaching a maximum load of 1191.44 kN. Moreover, the maximum contact stress is 1750.4 MPa, and the maximum Mises stress is 921.34 MPa during this operation. Importantly, when the load reaches 1218 kN, the maximum Mises stress of the track roller is 930.2 MPa, which may lead to roller failure after prolonged use. These findings provide valuable insights for the design and optimization of heavy-duty track rollers and offer significant assistance for various tracked vehicles. [ABSTRACT FROM AUTHOR]

This study proposes a novel anisotropic model based on fractal theory for three-dimensional (3D) rough surface reconstruction to improve the large error associated with isotropic models. The proposed model comprises a fractal-based two-dimensional (2D) contour curve, a conversion operator and a coefficient vector ratio. The effects of the virtual random curve and fractal-based 2D contour curve in the conversion operator are discussed. The largest height ratio of the virtual contour curve and the measured surface discrete point curve of each column are used in the coefficient vector ratio. The rough surface is also smoothed using a five-point cubic smoothing algorithm. Compared with the isotropic model, the proposed model resembles the measured surface more closely with an average fitting error reduction of 49.84% and 64.7% before and after smoothing, respectively. The surface exhibits horizontal and vertical textures that can be controlled by the fractal dimension and roughness in the X and Y directions. Additionally, an asperity contact model is established and analysed. The proposed modelling method for anisotropic 3D rough surface contact condition is more consistent with the measured surface model. The transverse and longitudinal textures of the anisotropic surface can be changed by the fractal dimension and fractal roughness in the X and Y directions. This research provides insights into characterising 3D rough surfaces of high-precision gears and improving nominal contact area accuracy. [ABSTRACT FROM AUTHOR]

Spline connection is a key component for force- and torque-transmission, which is widely used in mechanical engineering. External splines in spline connection have been manufactured by rolling process, but the matched inner splines manufactured by plastic deformation are few. Especially, the long inner spline is usually manufactured by cutting process. The rolling process is a plastic forming process with local loading and force saving; so, this study investigated the rolling process and its implementing way for inner spline sleeve. A radial-feed rolling process and two through-feed rolling processes with different structure of entry-angle section were proposed, and the finite element (FE) models were established for different rolling process, respectively. For the FE model of the through-feed rolling process, a multiple meshing strategy is used such as the local refinement window moving along axial direction with rolling die and the total number of mesh increasing by stages. The results indicated that the contact area is the same along axial direction and increases in situ during radial-feed rolling process, but the contact area changes and moves along axial direction during through-feed rolling process; the full and clear shape of inner spline can be obtained by the three rolling processes, but the shapes near the end of expected zone with inner spline are different for the different processes, and the geometry near the end of billet and the rolling process have the influence on the shapes near the end; some metal is accumulated in front of the through-feed rolling die, so non-full teeth present in the entered end by the rolling die and full teeth in the exited end will be out of the expected zone with inner spline. [ABSTRACT FROM AUTHOR]

Single layer graphene (G) and fluoride doped tin dioxide(FTO) thin film were compounded together by wet etching method. The structure, surface and interface topography and elemental distribution of G/FTO bilayer film were investigated by Raman spectroscopy, focused ion beam (FIB) and transmission electron microscopy (TEM). The topography, contact potential difference (CPD), work function and contact barrier of FTO film and G/ FTO bilayer film were investigated using Kelvin probe force microscopy (KPFM) and conductive atomic force microscopy (C-AFM) based on atomic force microscopy (AFM). The results show that the contact potential difference of FTO film and G/ FTO bilayer film is -0.474 and -0.441 V, respectively, and the work function of the two films is 5.329 and 5.296 eV, respectively. Compared with FTO film, the mobility of G/FTO bilayer film increases from 21.26 cm²⋅V-1⋅s-1 to 23.82 cm²⋅V-1⋅s-1. The corresponding barrier height of FTO film and G/ FTO bilayer film is (0.39 ± 0.06) V and (0.33 ± 0.05) V, respectively, and the barrier height of G/ FTO bilayer film is smaller. [ABSTRACT FROM AUTHOR]

In order to study the influence of initial installation deformation of floating oil seal 0-ring,based on the An-sys Workbench platform,a two-dimensional axisymmetric finite element model of the floating oil seal was established,and the nonlinear contact analysis during the installation process was carried out by considering initial installation deformation of floating oil seal 0-ring. The effects of different oil pressure, installation clearance, and hardness on the stress, contact pressure,contact friction force of the 0-ring and the supporting reaction force of the floating seal ring end cover were studied.The results show that when considering the installation process,the 0-ring is not located in the relatively central position in the floating oil seal, but in the upper position in the middle of the floating oil seal, and the maximum von Mises stress of the 0-ring is greater than that without considering the installation process,so considering the installation process of the 0-ring is more in line with the actual situation.The maximum von Mises area will become smaller and narrower with the increase of oil pressure,which will increase the risk of crack failure.The maximum contact friction is concentrated on the end face of the floating seal ring,and the contact length increases continuously with the increase of oil pressure.The increase rate of the force in the y direction of the floating seal ring end cover far exceeds the increase rate of the force in the x direction.Under the condition of constant oil pressure,the stress increases with the decrease of installation clearance,and the stress increases with the increase of hardness. The maximum contact pressure of the floating oil seal is greater than the oil pressure within the oil pressure range of 2 MPa,which can ensure the self-sealing of the floating oil seal. [ABSTRACT FROM AUTHOR]

Contact characteristic is an important index to characterize the transmission performance of gears. To clarify the contact characteristic of a nutation transmission with double circular-arc spiral bevel gears, this paper carried out a loaded tooth contact analysis by using the finite element method. Firstly, based on the meshing theory, the tooth surface equation of the double circular-arc spiral bevel gear was derived based on which a three-dimensional CAD model of the meshing gear pair was generated. Secondly, a finite element model of the gear pair was developed in Ansys Workbench to simulate contact status of the meshing double circular-arc spiral bevel gear pair. Finally, the influence of load and installation error on the transmission performance of the gear pair was investigated. The results show that a double-point contact occurs on concave and convex tooth surfaces of the double circular-arc spiral bevel gear, and the stress maximum occurs at the toe of bevel gear. With the increase of load, the contact ratio of the meshing gear increases, while the load distribution coefficient decreases, which improves the smoothness of gear transmission. The installation error affects the contact state of the gear pair in that a negative offset error and a positive nutation angle error may degrade the bearing capacity and the transmission stability of the gears. Thus, they should be reasonably controlled in practical applications.

Bolt connection is an important component in mechanical structure which significantly affects the dynamic property of the whole structure. In this paper, a three-dimensional transition interface model which contains geometric and physical parameters is proposed to model the bolted joint based on the contact analysis. The geometric parameters and the physical parameters are used to characterize the influence of contact area and contact pressure which are related to connection parameters such as material, roughness, connection thickness, and tightening force, respectively. After that, the geometric parameter identification method is proposed, and the geometric parameter database of bolt joints for machine tools is constructed based on the Kriging interpolation method. Then, the model updating method based on the combination of modal parameters and frequency response function is proposed to identify the physical parameters and thickness of the three-dimensional transition interface model. The database of the transition interface model is constructed after verifying the validity of the proposed model. Finally, an engineering example of an engraving machine tool is used to check the practicability of the proposed transition interface model and the usage of the constructed parameter database. [ABSTRACT FROM AUTHOR]

To overcome the problem of frequency consistency and simplify the design process of linear ultrasonic motor, a novel traveling wave linear ultrasonic motor with a ring-type stator is proposed in this paper. The combination of two orthogonal bending vibration modes with the same order is selected as the operating mode of the motor. A traveling wave along the side of the stator is utilized to drive the slider to move linearly. The stator adopts a ring symmetrical structure, which can effectively ensure that the resonance frequencies of the two vibration modes are consistent. Thus, we do not need to tune the frequencies of the two vibrations by constantly adjusting the shape of the stator or designing complex clamping parts to fix the stator without making any influence on the vibrations. Meanwhile, a three-dimensional finite element model of the motor is built. Using the model, we obtain the elliptical motion trajectories of the stator driving surface, the output performance of the motor, the sticking-slipping-separation contact characteristic between the stator and the slider and fabricate and measure a prototype of the proposed motor. [ABSTRACT FROM AUTHOR]

• A comprehensive stiffness model of intermediate bearing is presented. • A reduced model of dual rotor-bearing-casing coupling system is developed. • The effects of typical parameters on the vibration of the system are discussed. • The mechanism of the comprehensive stiffness and system vibration is revealed. This paper focuses on the vibrational properties of a dual rotor-casing coupled system with nonlinear clearance in the intermediate bearing, considering both the oil film stiffness and Hertzian contact stiffness between rolling elements and raceways. A comprehensive stiffness model for the intermediate bearing has been developed based on elastohydrodynamic lubrication (EHL) and Hertz contact theory. Subsequently, a dynamical model of the dual rotor-bearing-casing system is established using the finite element method, thereby verifying the feasibility of simulating the casing with beam elements. The dimensionality of the system equation is reduced using the fixed-interface component mode synthesis (CMS) method, and the resulting reduced-dimensionality equation is solved using the improved Newmark- β method. The effects of casing support, rotational speed, and radial clearance on the vibration characteristics of the system are investigated. Then, the comprehensive stiffness and coupled vibration characteristics of the system are analyzed to elucidate its intrinsic mechanism. Finally, the contact characteristics within the intermediate bearing under dynamic load are also studied. The results indicate that the support stiffness of the casing has a more significant impact on the second resonance caused by both the inner and outer rotors. The system is prone to experiencing varying compliance (VC) resonance at low rotational speeds. The excessive bearing clearance leads to complex vibrational characteristics of the system, making it challenging to predict its motion. The impact of minor changes in stiffness on system vibration is small when the comprehensive stiffness is large. At this time, the limited effect of oil film stiffness allows it to be disregarded in terms of comprehensive stiffness. Furthermore, the speed significantly influences the contact characteristics within the intermediate bearing under the unbalanced force of the rotor and gravity. [ABSTRACT FROM AUTHOR]

Angular contact ball bearings are widely used in rotating machinery. The external moment about the bearing lateral direction (i.e. the lateral moment) applied to a bearing affects the service life and performance of the bearings by influencing its internal contact characteristics. This work established a quasi-dynamic model of the ball bearing by comprehensively considering the inclination angle of the inner ring due to external lateral moment, the viscous drag, the inertial force and moment of the ball, the spin and sliding of the ball in the contact ellipse. On this basis, the operation process of angular contact ball bearings was simulated under combined radial and moment loads. The effectiveness of the model was verified experimentally, and the influences of external moments about different directions on the contact angle, slip-roll ratio, and load distribution under combined loads were analyzed. The results show that the increase in moment intensifies the spin-sliding of the rolling element. When the lateral moment and the radial load are applied together, the lateral moment can reduce the maximum load of the rolling element and causes the maximum load of the rolling element to deviate from its original position. When the lateral moment is combined with the axial and radial loads, the bearing load zone is concentrated by the rolling elements near the lateral direction. The curve of the load distribution changes from an ideal oval to a distorted oval. The research results can be used to guide the design, service life calculation, and performance evaluation of rolling bearings. • A comprehensive quasi-dynamic model of bearing is established considering some nonlinear factors. • Experimental validation of the proposed model is performed. • Influences of combined loads and moments on contact characteristics are investigated. [ABSTRACT FROM AUTHOR]

Bolt connection is an important component in mechanical structure which significantly affects the dynamic property of the whole structure. In this paper, a three-dimensional transition interface model which contains geometric and physical parameters is proposed to model the bolted joint based on the contact analysis. The geometric parameters and the physical parameters are used to characterize the influence of contact area and contact pressure which are related to connection parameters such as material, roughness, connection thickness, and tightening force, respectively. After that, the geometric parameter identification method is proposed, and the geometric parameter database of bolt joints for machine tools is constructed based on the Kriging interpolation method. Then, the model updating method based on the combination of modal parameters and frequency response function is proposed to identify the physical parameters and thickness of the three-dimensional transition interface model. The database of the transition interface model is constructed after verifying the validity of the proposed model. Finally, an engineering example of an engraving machine tool is used to check the practicability of the proposed transition interface model and the usage of the constructed parameter database.

In order to overcome ablation on the rail–armature contact region and increase electromagnetic thrust force, a structure of armature arm with interference fit is designed in augmented quadrupole electromagnetic launcher (EML). Good contact characteristic between the armature and rails plays an important role in the success of EML. The electromagnetic-structure coupling model based on the finite element analysis is presented to investigate the contact characteristic, the distribution of current density, and the electromagnetic force (EMF) and the contact pressure is given, which indicates the EMF needs to be loaded unevenly on the armature arm. Finally, based on electromagnetic-structure coupling model, some important parameters including the contact area, the contact efficiency, the contact counterforce, and maximal contact pressure are analyzed with the different interference, different length, and different thickness of armature arm after the pulse current is loaded. The dependences of nonuniform contact parameters on the nonuniform EMF are obtained. [ABSTRACT FROM AUTHOR]

To overcome the problem of frequency consistency and simplify the design process of linear ultrasonic motor, a novel traveling wave linear ultrasonic motor with a ring-type stator is proposed in this paper. The combination of two orthogonal bending vibration modes with the same order is selected as the operating mode of the motor. A traveling wave along the side of the stator is utilized to drive the slider to move linearly. The stator adopts a ring symmetrical structure, which can effectively ensure that the resonance frequencies of the two vibration modes are consistent. Thus, we do not need to tune the frequencies of the two vibrations by constantly adjusting the shape of the stator or designing complex clamping parts to fix the stator without making any influence on the vibrations. Meanwhile, a three-dimensional finite element model of the motor is built. Using the model, we obtain the elliptical motion trajectories of the stator driving surface, the output performance of the motor, the sticking-slipping-separation contact characteristic between the stator and the slider and fabricate and measure a prototype of the proposed motor.

The precise mathematical model for the tooth surface and transition surface of spiral bevel gears is derived. Taking a pair of spiral bevel gears of a heavy vehicle as an example of calculation and analysis, a finite element model of spiral bevel gears transmission system is established. Through the finite element tooth contact analysis under quasi-static loading and high loading condition, the influences of torque on the root stress distribution, contact stress, and transmission error are discussed, and the results are compared with the empirical formula results. Finally, a contact performance test bench of spiral bevel gear pair is developed, then the root bending stress, contact pattern, and transmission error tests are carried out. These experiment results are compared with analyzed ones, which showed a good agreement. [ABSTRACT FROM AUTHOR]

To overcome the shortcomings of traditional rigid road wheel, such as poor damping effect and low loadbearing efficiency, a new type of flexible road wheel, having a unique suspension-bearing mode, was introduced. The three-dimensional nonlinear finite element model of rigid and flexible road wheel, considering the triple nonlinear characteristics of geometry, material and contact, is established for numerical investigation of static loading performance. The accuracy of the finite element model of the rigid and flexible road wheel is verified by static loading experiment. The static loading performance of the rigid and flexible road wheels is numerically analyzed. The influence of vertical load on maximum stress and deformation of the rigid and flexible wheels is also studied. The results show that the contact pressure uniformity of the flexible road wheel is better than that of the rigid road wheel under the static vertical load, but the maximum stress and deformation of the flexible road wheel are greater than that of the rigid road wheel. However, this problem can be solved by increasing the number of hinge sets and optimising the joints. The research results provide theoretical basis for replacing rigid road wheel with flexible road wheel, and also provide reference for structural optimisation of flexible road wheel. [ABSTRACT FROM AUTHOR]

As the current research about the dynamics of roller overrunning clutch in the transmission system of loader is insufficient,on the basis of virtual prototype technology,the simulation analysis of the working process of loader roller overrunning clutch is carried out. The typical operating conditions of overrunning and wedging of the roller overrunning clutch used by loader are chosen to be analyzed by using the multi-body dynamic stimulation analysis software ADAMS,and consequently several important parameters,such as the response characteristic of spring in overrunning,the engagement time and impact load in wedging etc.,are obtained,which provides reference for a better understanding of the working process of overrunning clutch.

Based on the dynamics of rolling bearing,an improved slice method is used to solve the problem of needle-race contact,and the dynamics differential equations are established and solved by Predicting-Correcting GSTIFF（ Gear Stiff） integer algorithm with variable step. The impact of working parameters and roller crowned shape on the stress distribution of needle-race and bearing life is investigated theoretically,and it shows that,working conditions of bearing and roller crowned shape both have large effect on the fatigue life of bearing. Therefore,the optimum crowned shape of roller should be determined according to the working conditions of bearing.

Taking the roller-type overrunning clutch as study object,based on the contact theory of Hertz,the contact stress between the key driving parts of the roller overrunning clutch is analyzed and studied.First,by analyzing the two common mechanical models of the overrunning clutch,the positive pressure P between the corresponding contact pair is obtained and then the Hertz stress value is calculated. Then,the application conditions of two mechanical methods are put forward through combining the contact optimization theory of Hertz. Besides,several parameters,such as contact stress,sliding distance that can reflect the contact characteristics of contact pair are obtained with the application of the finite element analysis software ANSYS,which actually verifies the adaptive conditions of two mechanical methods. The research results indicate that mechanical analysis method,which takes the coefficient of friction into consideration,is much more appropriate to the theoretical calculation,and the idealized line contact analysis model is suitable for the actual working condition,which provides a solid theoretical foundation for further understanding of the overrunning clutch operating characteristics and follow-up optimization design.

Composite automated placement shows great potential for efficient manufacturing of large aviation components. In order to understand the effect of the contact between the compaction roller and the fiber/tape on the layup quality, it is necessary to study the contact characteristic of the compaction roller and the morphological change of the prepreg under the compaction roller. The contact of the compaction roller is divided into the static and dynamic contact. For the static contact, the contact model is simplified to a roller compaction on an elastic body with curved surfaces, and it is developed based on the elastic contact theory. On the contrary, a dynamic contact model is presented by simplifying the contact areas as idealized rectangular elements with identically sized elements. Due to the compaction roller exerting pressure on the prepreg, the morphology of the prepreg will change with different processing parameters. The deformation model of the prepreg is determined as the resin flows through a porous network of fibers by creep theory. A series of experiments had been conducted to verify feasibility and accuracy of the developed models. Results demonstrate that these models have good precision. [ABSTRACT FROM AUTHOR]

Interface research is one of the basic topics in the study of mass transfer dynamics and actuation deformation processes. The main objective of this paper is to conduct in-depth research on the interface characteristics of ionic electroactive polymers, and this problem has not been studied to a large extent until now. The formation of the interface is closely related to the factors such as substrate pretreatment, the electroless plating process and the adsorption of ions. The interface has an irregular and self-similar microstructure, fractal theory can well analyze its intrinsic fractal characteristics. Based on the three-dimensional rough interface, the fractal characteristics of six two-dimensional cross-sections were identified. The fractal dimension, relative error, correlation coefficient and scale-free interval obtained by these six methods were quantitatively compared. The interfacial morphological characteristics of the ion-activated polymer were analyzed experimentally and the optimal fractal dimension calculation method was determined. A fractal contact model of the ionic electroactive polymer was developed and the calculation of the peel strength of the interface was proposed. The results show that RMSM is a feasible and effective method for the fractal characterization of the profiles of ionically electroactive polymers. The interfacial contact model based on fractal features can effectively characterize the peeling strength of the interface, which can provide a reference for later microscopic fractal studies on the theories of mass transfer process, actuation deformation and ion migration. [ABSTRACT FROM AUTHOR]

The contact characteristics of deep groove ball bearing（ DGBB） is one of the important factors that influence the DGBB property,for analyzing the influence of curvature radius on the contact characteristics of DGBB,taking the SKF618 /8 single row DGBB used in the planetary transmission mechanism as example.The stress,strain,velocity,contact force are simulated and analyzed based on the finite element software,and the influence of different curvature radius of inner ring,outer ring and the diameter of the roller on its contact characteristics are analyzed. The results show that the velocity,stress and strain of roller are variations in the form of peaks and troughs,and the stress,strain are mainly concentrated in the contact area between the roller and the inner or outer circle. The roller stress is increased with the curvature radius of inner ring,outer ring and rolling element diameter,moreover,the speed of the rolling element is greater with the longer of the distance to the center of rotation. Furthermore,the volatility and contact force of DGBB between the rolling element and inner or outer ring have the similar size,which basically the same with the radial load value,but the force between rolling element and maintains is small.

The precise mathematical model for the tooth surface and transition surface of spiral bevel gears is derived. Taking a pair of spiral bevel gears of a heavy vehicle as an example of calculation and analysis, a finite element model of spiral bevel gears transmission system is established. Through the finite element tooth contact analysis under quasi-static loading and high loading condition, the influences of torque on the root stress distribution, contact stress, and transmission error are discussed, and the results are compared with the empirical formula results. Finally, a contact performance test bench of spiral bevel gear pair is developed, then the root bending stress, contact pattern, and transmission error tests are carried out. These experiment results are compared with analyzed ones, which showed a good agreement.

The tapered roller bearing has great influence on rotary machine with high load,and hollow roller bearing is applied in significant engineering right now.According to Hertz contact theory and FEM,the equivalent three- dimensional simulation model of single roller-ring solid and hollow tapered roller bearing is established in ANSYS separately,the influence rule of various hole rate and load on elastic deformation and contact stress etc is analyzed.As a result,contact stress value is verified by theoretical calculating result.Simultaneously,the analysis one affords reference for optimal design and engineering application of tapered roller bearing.

It has been demonstrated that chatter has a negative effect on machined surface quality during milling process. The identification of chatter is crucial for reducing its influence on machining integrity, especially for the milling process of curved surface. Change of cutter position will cause chip thickness to vary in milling process. Therefore, different contact characteristic between milling cutter and workpiece will be brought out. Compared with the traditional predictive model, a model for predicting chatter stability considering this contact characteristic is proposed in this study. Stability lobe diagrams at different cutter positions are proposed to predict milling stability by employing full-discrete method. A series of experiments are carried out to calibrate and verify the stable lobe diagram. The predicting result is in good agreement with experimental investigation for the stability characterization of curved surface milling process. The model proposed in this study could be used to improve machined quality for curved surface. [ABSTRACT FROM AUTHOR]

From a point of view of handling and stability, it is important to bring automotive tires into contact with the road correctly. If the contact state of the tire is known while moving, more advanced vehicle control can be carried out. However it is difficult to know whether tires contact with road correctly and tires produce the force enough to drive safety while moving. In this research, we formulate how to estimate contact patch's condition and side force, slip angle, camber angle of the tire using tire tester machine by measuring the deformation of tires with the strain gauges of three places attached in the inner. In addition to the strain in the circumferential direction of the prior art, the lateral direction is measured newly. From the measurement results, the vertical load could be estimated from the contact length of the middle, the lateral force and slip angle could be estimated from the relationship between the lateral force and slip angle the ratio of the contact length of the left and right, camber angle could be estimated from the relationship of the difference between the right and left lateral strain and the ratio of the contact length. By mounting a tire with a strain gauge, it is possible to clarify vertical load, slip angle, camber angle, which is a parameter necessary for the vehicle state estimation.

Copyright of Jianzhu Cailiao Xuebao: Journal of Building Materials is the property of Journal of Building Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• A five degree-of-freedom model of duplex angular contact ball bearings is proposed for back-to-back, face-to-face and tandem configurations. • Bearing contact characteristic and stiffness significantly depend on the ring misalignment. • The results demonstrate the necessity of misalignment effect analysis for duplex angular contact ball bearings. Ring misalignment is unavoidable in most applications of bearing and significantly affects bearing performance. However, it has not been thoroughly studied for duplex angular contact ball bearings. To overcome the deficiency, this paper presents the analysis for duplex angular contact ball bearings by considering inner ring angular misalignment. A highly modular five degree-of-freedom model of duplex angular contact ball bearings is proposed based on vector-and-matrix method for back-to-back, face-to-face and tandem configurations. Five-dimensional stiffness matrix of bearing is also presented. On the basis, influences of ring misalignment on load distribution, maximum and average contact loads of bearing with back-to-back and face-to-face configurations are analyzed. Finally, translation and tilting stiffness coefficients of bearing are further discussed under misalignment condition. The results show that, ring misalignment considerable changes the contact characteristic of ball-raceway and causes uneven load distribution. Ring misalignment affects the position of maximum contact load and significantly impacts the diagonal stiffness of bearing. Contact characteristics and stiffness are also dependent on the bearing configuration. The results suggest the importance of bearing alignment and demonstrate the necessity of misalignment effect analysis. [ABSTRACT FROM AUTHOR]