Transverse Force Research Articles

RETRACTED: Study on the design of composite beams under complex environment in mountainous areas

The mountain area is faced with complex conditions such as vertical and horizontal valleys, complex geological topography, many earthquake fault zones, high seismic intensity, fragile ecology, and changeable climate. The traditional concrete bridges have a heavy weight, high consumption of sand and gravel materials, large structural dimensions of steel box composite bridges, high steel consumption, and poor overall horizontal performance of steel plate composite beams, which are not suitable for mountain construction conditions. Therefore, based on the construction environment and application requirements of highway bridges in mountainous areas, the structural scheme of steel box-steel plate composite beam is put forward in this paper, and the design of a 25 m–50 m standard-span steel box-steel plate composite beam is studied. The results show that the steel box-steel plate composite beam structure scheme is adopted, which has excellent mechanical characteristics of steel box girder and simple structure of steel plate girder. It has the mechanical characteristics of “balanced transverse force and excellent longitudinal force”, so it is a reasonable choice for small radius curved beam bridge in a mountainous area, so it is a reasonable choice for small radius curved beam bridge in a mountainous area. The steel box-steel plate composite beam adopts the integrated technology of manufacture, transportation and installation, which can better meet the road transport conditions in the mountain area. The longitudinal assembly of the manufacturing unit as the installation unit can ensure the rapid and high-precision installation of the construction site, and the assembly construction of the bridge in the mountain area has been realized. The technical and economic comparison shows that the mechanical performance of steel box-steel plate composite beam is similar to that of steel box beam and obviously better than that of steel plate girder. The steel consumption and construction period of steel box-steel plate composite beam are similar to that of steel plate girder, and are significantly less than that of the steel box girder. Therefore, the steel box-steel plate composite beam is a good choice for mountain bridge construction.

Study on Vibration Characteristics of Hydraulic Pipes in Case of Internal Pulsating Fluid Excitation

The influence of transverse external periodic force on the fluid-structure interaction vibration of hydraulic pipe was researched. Through stress analysis on the pipe under the effect of internal flow, the Bernoulli-beam model in the paper was selected. The equation of fluid-structure interaction vibration was established. By comparing the simulation results of load and no load the transverse external periodic force, a length of hydraulic pipe was analyzed using ansys cfx. The results were shown that the transverse external periodic force strengthened the hydraulic oil’s pressure fluctuation of the pipe internal and the fluid-structure interaction vibration.

A first analysis of possible elementary causes of self‐excited vibrations in roller coaster rides

AbstractThe emergence of vibrations during a roller coaster ride is a recurring phenomenon that can deteriorate the overall experience and accelerate material fatigue. Nevertheless, the causes of such vibrations are still not completely understood and are consequently not fully predictable during the design process. One possible source lies on the irregularities of the rails, acting as a forced external excitation. However, a spectral analysis shows deviations with respect to real measurements [1], as the frequencies are not synchronous with the car velocity divided by the spatial irregularity period. Therefore, there is an indication that the vibrations may be due to self‐excitation and/or that the developed models should consider other phenomena not yet contemplated. This investigation analyses –for the first time to the knowledge of the authors– the plausibility of various causes of self‐excited vibrations during a roller coaster car motion. Given the complex structure of a real roller coaster train and the intricate geometry of the track, the study considers as a first step minimal dynamical models running along a straight track. The cause analyzed in this paper is the contribution of the transversal friction force component that develops in the wheel‐rail contact interface to the destabilization of the longitudinal motion, as well as the effect of the various geometrical and inertial parameters. In this first analysis, no external excitation is considered. For a range of parameters, the minimal system presents a Hopf bifurcation. The results are plausible from the general behavior and thus this cause may be retained as a candidate for the real vibrations occurring in roller coasters. However, the applicability of these preliminary results to general roller coaster motions is not yet confirmed, but a superposition with other causalities may render effective. In further investigations, a complete train motion on curved tracks and external perturbations will be studied to determine the share of the different causes.

Experimental Study of Wind Loads on Tubular Crossarms of Transmission Towers

The actions exerted by yawed wind on the crossarm substantially differ from those on the tower body due to the presence of the angle between the crossarm’s cross-section and the incoming flow, and this phenomenon deserves a better understanding. Focusing on the tubular crossarms with round-section members, this paper aims to determine insights into wind actions, as affected by various factors, such as the tower type, the mean width to mean height ratio, the solidity ratio, and the wind incidence angle, and thereby derive the wind loads for design. Accordingly, a succession of wind tunnel tests was conducted by using quadrilateral and triangular crossarm models with various solidity ratios and mean width to mean height ratios. The method of direct force measurement (DFM) is employed for the high frequency force balance (HFFB) test to attain the transverse and longitudinal forces on the crossarm simultaneously. It was found that the wind load coefficients increase with increases of the mean width to mean height ratio and decreases of the solidity ratio. Moreover, in the case of the incoming flow perpendicular to the crossarm face, it is concluded that compared to the quadrilateral crossarm, the triangular crossarm possesses a relatively smaller drag coefficient, provided a moderate mean width to mean height ratio of 1.19. Furthermore, an analysis of the experimental results shows that the skewed wind load factor specified in the relevant codes would overestimate the effects of the wind incidence angle and the variations in mean width to mean height ratio, which is evident in the tests but not considered in the codes. It is worth noting that the experimental results show that the crosswind force is pronounced, which is usually ignored in the skewed wind load factor-based approach. Comparatively, using wind load distribution factors seems to be more rational. Thus, the corresponding estimating equations are proposed for the wind load-distribution factors of the crossarms, which agree well with the experimental results. The developed equations would greatly facilitate the determination of wind loads on tubular crossarms.

Analysis of strut‐based lattice cores in sandwich panels using homogenization and dehomogenization methods

AbstractThe design freedom provided by additive manufacturing offers new opportunities to fabricate novel structures with a high lightweight potential, such as strut‐based lattice structures. These lattice structures consist of periodically repeated unit cells and can be used in several applications due to their outstanding mechanical performance. One of the possible applications are cores of sandwich panels since the strut‐based lattices offer comparable mechanical properties to conventional honeycomb structures. Moreover, multifunctional use of the sandwich core is enabled by allowing the heat and fluid transfer through the sandwich due to the open‐celled lattice structure. However, strut‐based lattices are rarely utilized as cores in sandwich panels in engineering practice. One of the main reasons for that is the unknown mechanical behavior of lattice cores. In particular, when the sandwich is subjected to concentrated loads, localized stresses and deformations occur in the sandwich core, leading to core damage. In this work, we present a novel analytical model to determine stresses and deformations in the struts of lattice cores of sandwich panels using homogenization and dehomogenization methods. The local core compression caused by localized transverse forces can also be determined by the derived model.

Inverse problems of identifying the unknown transverse shear force in the Euler–Bernoulli beam with Kelvin–Voigt damping

Abstract In this paper, we study the inverse problems of determining the unknown transverse shear force g ⁢ ( t ) {g(t)} in a system governed by the damped Euler–Bernoulli equation ρ ⁢ ( x ) ⁢ u t ⁢ t + μ ⁢ ( x ) ⁢ u t + ( r ⁢ ( x ) ⁢ u x ⁢ x ) x ⁢ x + ( κ ⁢ ( x ) ⁢ u x ⁢ x ⁢ t ) x ⁢ x = 0 , ( x , t ) ∈ ( 0 , ℓ ) × ( 0 , T ] , \rho(x)u_{tt}+\mu(x)u_{t}+(r(x)u_{xx})_{xx}+(\kappa(x)u_{xxt})_{xx}=0,\quad(x,% t)\in(0,\ell)\times(0,T], subject to the boundary conditions u ⁢ ( 0 , t ) = 0 , u x ⁢ ( 0 , t ) = 0 , [ r ⁢ ( x ) ⁢ u x ⁢ x + κ ⁢ ( x ) ⁢ u x ⁢ x ⁢ t ] x = ℓ = 0 , - [ ( r ⁢ ( x ) ⁢ u x ⁢ x + κ ⁢ ( x ) ⁢ u x ⁢ x ⁢ t ) x ] x = ℓ = g ⁢ ( t ) , u(0,t)=0,\quad u_{x}(0,t)=0,\quad[r(x)u_{xx}+\kappa(x)u_{xxt}]_{x=\ell}=0,% \quad-[(r(x)u_{xx}+\kappa(x)u_{xxt})_{x}]_{x=\ell}=g(t), for t ∈ [ 0 , T ] {t\in[0,T]} , from the measured deflection ν ⁢ ( t ) := u ⁢ ( ℓ , t ) {\nu(t):=u(\ell,t)} , t ∈ [ 0 , T ] {t\in[0,T]} , and from the bending moment ω ⁢ ( t ) := - ( r ⁢ ( 0 ) ⁢ u x ⁢ x ⁢ ( 0 , t ) + κ ⁢ ( 0 ) ⁢ u x ⁢ x ⁢ t ⁢ ( 0 , t ) ) , t ∈ [ 0 , T ] , \omega(t):=-(r(0)u_{xx}(0,t)+\kappa(0)u_{xxt}(0,t)),\quad t\in[0,T], where the terms ( κ ⁢ ( x ) ⁢ u x ⁢ x ⁢ t ) x ⁢ x {(\kappa(x)u_{xxt})_{xx}} and μ ⁢ ( x ) ⁢ u t {\mu(x)u_{t}} account for the Kelvin–Voigt damping and external damping, respectively. The main purpose of this study is to analyze the Kelvin–Voigt damping effect on determining the unknown transverse shear force (boundary input) through the given boundary measurements. The inverse problems are transformed into minimization problems for Tikhonov functionals, and it is shown that the regularized functionals admit unique solutions for the inverse problems. By suitable regularity on the admissible class of shear force g ⁢ ( t ) {g(t)} , we prove that these functionals are Fréchet differentiable, and the derivatives are expressed through the solutions of corresponding adjoint problems posed with measured data as boundary data associated with the direct problem. The solvability of these adjoint problems is obtained under the minimal regularity of the boundary data g ⁢ ( t ) {g(t)} , which turns out to be the regularizing effect of the Kelvin–Voigt damping in the direct problem. Furthermore, using the Fréchet derivative of the more regularized Tikhonov functionals, we obtain remarkable Lipschitz stability estimates for the transverse shear force in terms of the given measurement by a feasible condition only on the Kelvin–Voigt damping coefficient.

A Passively Conforming Soft Robotic Gripper with Three-Dimensional Negative Bending Stiffness Fingers.

Robot grippers that lack physical compliance have a difficult time dealing with uncertainty, such as fragile objects that may not have well-defined shapes. Existing soft robotic grippers require a large empty workspace for their actuated fingers to curl around the objects of interest, limiting their performance in clutter. This article presents a three-dimensional structure that exhibits negative stiffness in every bending direction used as fingers in a class of soft robotic grippers. Our approach exploits a compliant mechanism in a conical shape such that a transverse external contact force causes the fingers to bend toward the contact, enabling passive conformation for an adaptive grasp, even in clutter. We show analytically and experimentally that the proposed fingers have a negative bending response and that they conform to objects of various diameters. We demonstrate a soft robotic gripper with three self-conforming fingers performing the following: (1) fingertip grasping, (2) power grasping, and (3) semipassive grasping in clutter. Grasping experiments focus on picking fruits, which exemplify delicate objects with unmodeled shapes with significant variation. The experimental results reveal the ability of the self-conforming structure to smoothly envelope a broad range of objects and demonstrate a 100% grasp success rate in the experiments performed. The proposed passively conforming fingers enable picking of complex and unknown geometries without disturbing nearby objects in clutter and without the need for complex grasping algorithms. The proposed structures can be tailored to deform in desired ways, enabling a robust strategy for the engineering of physical compliance for adaptive soft structures.

Assessing the effect of a thickness gradient on the shear stress profile at the epoxy/silicone interface of thin coatings subjected to transverse shear loads with finite element analyses

ABSTRACT Low surface energy materials are used as foul-release coatings (FRCs) to reduce the forces required to remove biofouling. Previous experiments observed the release behavior of epoxy studs (pseudobarnacles) from silicone coatings with a thickness gradient. The studs were loaded transversely in thick-to-thin and thin-to-thick directions, and the final decohesion always proceeded from the thin to the thick side of the coating. However, trends in the critical transverse forces required for removal were not apparent. In this study, finite element models (FEMs) were created to determine the peak shear stress at the interface of an epoxy stud bonded to a silicone coating with a thickness gradient in response to a transverse load. The effects of the average coating thickness, the thickness gradient of the coating, and the transverse loading direction were determined. At a given average coating thickness, increasing the thickness gradient produced higher peak shear stresses at the interface, which would reduce the critical force required to remove the epoxy stud (i.e., would improve the performance of the FRC). The influence of the increased thickness gradient waned as the average coating thickness increased. Therefore, moderately thin coatings with large thickness gradients would be optimal for FRC performance under transverse loading.

Theoretical analysis on carbon fiber reinforced aluminum laminate under off-center impact

Carbon fiber reinforced aluminum laminate (CARALL) composed of multi-layer CFRP and aluminum has better toughness and impact resistance than composite laminates due to the existence of metal. This work investigates the energy absorption mechanism and creatively proposes a theoretical analysis model to predict the dynamic response of CARALL under off-center impact. Firstly, based on a simplified ideal rigid-plastic material model, a unified yield criterion and its simplified method for hybrid plastic hinges are proposed. Then, the analytical solution for maximum transverse displacement and impact force of CARALL under off-center impact is established. Finally, it is verified by the simulation and discussed in detail. The results show that the established theoretical method can predict the structural response under low-velocity impact.

A Ring Core Fiber Sensor Based on Mach–Zehnder Interferometer for Transversal Force Sensing With Solvable Temperature Cross Sensitivity

In this work, we proposed a ring core fiber (RCF)-based all-fiber sensor used for transverse force sensing. The sensor is composed of 1-mm coreless fiber (CLF) and 2.5-cm RCF. Then, the coreless (CL)-ring core (RC) fiber structure is connected to two segments of single-mode fibers to form a Mach–Zehnder interferometer (MZI). The transmission spectrum of the MZI structure has a large extinction ratio (ER) of up to 20 dB with a free spectral range (FSR) of 9.3 nm. After the fabrication, the MZI sensor is packaged for force sensing at different temperatures. The different values of forces are applied on the fiber sensor, which are tuned from around 0.26 to 1.5 N/mm. With the increase of transverse force, the spectra of output signals show a linear redshift. The force sensitivity of the proposed MZI sensor reaches up to 4.109 nm/(N/mm) with a good linearity of 0.9824. By using a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times2$ </tex-math></inline-formula> matrix, the temperature cross sensitivity can be extracted. The proposed force sensor based on the MZI fiber structure shows great potential applications in the field of structural health monitoring and supercapacitor safety detection.

Study of transient analysis of a conductive beam carrying an electrical current subjected to magnetic field with elastically restrained ends

The present study considers the nonlinear vibration behavior of a beam with general boundary conditions that carry an electrical current in the magnetic field. This paper discusses the magnetic couple, the transverse magnetic force, the electrical current, and the damper. By contrast, the magnetic field is selected as an arbitrary function of time. Under certain hypotheses, Hamilton's principle is used along with Maxwell's equations to derive the governing equation. An elastically restrained beam carrying an electrical current is also solved using Galerkin's method under a magnetic field. Thus, the effect of the rotational and the translational support flexibilities, the magnetic field, and other parameters are evaluated. For a more detailed investigation, some numerical examples are investigated to present the simplicity and efficiency of this formulation. Based on the numerical results, it is clear that the natural frequency of the ferromagnetic beam is sensitive to the angle and magnetic field. By increasing magnetic field intensity, the magnitude of the natural frequency of the beam increases. But with the increase of the angle, the frequency value decreases. Therefore, at larger angles, the impact of the intensity of the magnetic field will be less. Also, it is determined from the results that the beam deflection in various magnetic fields indicates a significant effect of the boundary conditions, not only on the dynamic response of a damped beam but also on the rate of damping of the response. The dynamic response under the magnetic field is decreased when the beam experiences a stiffer constant in its support. The results are shown that the effect of stiffening for the transitional support is more significant than that of the rotational support. Also, the influence of the boundary constraints becomes smaller when the magnetic field becomes smaller.

Selective phase filtering of charged beams with laser-driven antiresonant hollow-core fibers

Emerging accelerator concepts increasingly rely on the combination of high-frequency electromagnetic radiation with electron beams, enabling longitudinal phase space manipulation which supports a variety of advanced applications. The handshake between electron beams and radiation is conventionally provided by magnetic undulators which unfortunately require a balance between the electron beam energy, undulator parameters, and laser wavelength. Here we propose a scheme using laser-driven large-core antiresonant optical fibers to manipulate electron beams. We explore two general cases using ${\mathrm{TM}}_{01}$ and ${\mathrm{HE}}_{11}$ modes. In the former, we show that large energy modulations $O$(100 keV). can be achieved while maintaining the overall electron beam quality. Further, we show that by using larger field strengths $O$(100 MV/m) the resulting transverse forces can be exploited with beam-matching conditions to filter arbitrary phases from the modulated electron bunch, leading to the production of $\ensuremath{\approx}100$ attosecond FWHM microbunches. Finally, we also investigate the application of the transverse dipole ${\mathrm{HE}}_{11}$ mode and find it suitable for supporting time-resolved electron beam measurements with sub-attosecond resolution. We expect the findings to be widely appealing to high-charge pump-probe experiments, metrology, and accelerator science.

Trapping and manipulating skyrmions in two-dimensional films by surface acoustic waves

Skyrmions, topologically stable spin structures with particle-like properties, are promising for spintronics applications such as skyrmion racetrack memory. Though reliable control of skyrmion motion is essential for the operation of spintronics devices, the straight motion of skyrmions along the driving force is in general difficult due to an inevitable transverse force originating from their topology. Here, we propose a method of precise manipulation of skyrmions based on surface acoustic waves (SAWs) propagating in two dimensions. Using two standing SAWs, saddle-shape local potentials like quadrupole ion traps are created to trap skyrmions robustly. Furthermore, by tuning the frequencies of the SAWs, we show that trapped skyrmions not only move in straight lines but also move precisely in any direction in a two-dimensional thin film. These results could be helpful for the future design of spintronics devices based on skyrmions.

EXPERIMENTAL AND NUMERICAL INVESTIGATION OF DOWEL STRIPS FOR LONGITUDINAL AND TRANSVERSE LOADING

AbstractA new field of application for dowel strips are orthotropic composite roadway slabs. In contrast to conventional composite steel bridge construction, the dowel strips create a two‐dimensional bond. As a result, they are not only exposed to longitudinal but also to transverse shear forces. Up to now, neither the load‐bearing capacity nor the load‐deformation behavior under transverse shear forces have been investigated. Furthermore, there are design related deviations from the current approval in form of a lower dowel distance. This paper presents two different types of push‐out tests, which provide new insights into small composite dowel strips under longitudinal and transverse loads. Based on these tests and numerical investigations, the effects of smaller dowel strips are analyzed and special features of the load transfer mechanism under transverse shear forces are highlighted. The investigations presented here were carried out as part of the AiF‐FOSTA research project P 1265 [1].

Resonant-Frequency-Adjustable Fiber Bragg Grating Accelerometer Based on Extra Transverse Force Loading

We propose a resonant-frequency-adjustable fiber Bragg grating (FBG) accelerometer. The accelerometer employs a special hexagonal energy transfer structure and a microhelical cylinder as a carrier. When the geophone vibrates, transverse force and axial force are applied to FBG at the same time, which breaks the traditional accelerometer that the FBG is only subjected to a single direction force. The resonant frequency can be changed by preadjusting the position of the microhelical cylinder. We introduced the structural principle and experimental model of the accelerometer and determined the structural parameters through finite-element simulation. In addition, we carried out a series of experimental tests, and the results show that the resonant frequency of the accelerometer can be increased from 680 to 980 Hz, and the frequency bandwidth is widened by 300 Hz. When the resonant frequency reaches 800 Hz, the maximum sensitivity can achieve 46.1 pm/g.

Patch loading resistance of slender plate girders with multiple longitudinal stiffeners

AbstractThere is currently no reliable and simple design method available in international literature for the determination of the patch loading resistance of slender plate girders having multiple longitudinal stiffeners. The current research focuses on the patch loading resistance of girders having multiple longitudinal stiffeners. An advanced numerical model is developed and verified by own laboratory test results. A numerical parametric study is executed to investigate the load‐carrying capacity of girders having typical bridge geometries. Analysing the numerical simulation results, the structural behaviour obtained is classified based on the stiffener stiffness. Effect of the different geometrical parameters on the patch loading resistance is evaluated with special focus on the stiffener stiffness and distance between the longitudinal stiffeners. The failure modes depending on stiffener stiffness are investigated and the local buckling type failure is characterised by minimum stiffness. For this specific failure mode, an improved design method is developed, giving reliable resistance within the analysed parameter range. The presented resistance model is consistent with the design philosophy of EN 1993‐1‐5. The applicability of the improved design equation has been investigated for multiple stiffener places in unequal distances, which is the common case in praxis, and for bending and transverse force (M–F) interaction.

Application of mathematical modeling for calculation of dock structures of the spillway construction of the Krasnodar reservoir

The article deals with modern issues of the application of mathematical modeling taking into account the changing parameters of the reliability of the final resource of the dock structures of the spillway construction of the Krasnodar reservoir. Hydraulic structures of the pressure front of the Krasnodar reservoir are designed and built as structures of the II capital class. Analyzing the performed mathematical modeling, we see that the sections in the wall are “dangerous” at the place where it adjoins the bottom. To perform static calculations, we select a strip with a width of 1 linear meter in the longitudinal direction. Authors apply all types of loads acting on the structure of the strip of the cross-section of the structure and determine the forces in the dangerous sections of the wall and bottom. The main one is the calculation of the structure in the transverse direction. To construct diagrams of bending moments and transverse forces in the bottom plate, with the worst-case scenario of the structure, during mathematical modeling, a model of the dock structures of the spillway construction of the Krasnodar reservoir was built and later various emergency situations under the influence of seismic loads were calculated.

Dynamics of fluctuations and thermal buckling in graphene from a phase-field crystal model

We study the effects of thermal fluctuations and pinned boundaries in graphene membranes by using a phase-field crystal model with out-of-plane deformations. For sufficiently long times, the linear diffusive behavior of height fluctuations in systems with free boundaries becomes a saturation regime, while at intermediate times the behavior is still subdiffusive as observed experimentally. Under compression, we find mirror buckling fluctuations where the average height changes from above to below the pinned boundaries, with the average time between fluctuations diverging below a critical temperature corresponding to a thermally induced buckling transition. Near the transition, we find a nonlinear height response in agreement with recent renormalization-group calculations and observed in experiments on graphene membranes under an external transverse force with clamped boundaries.

Intelligent VIV control of 2DOF sprung cylinder in laminar shear-thinning and shear-thickening cross-flow based on self-tuning fuzzy PID algorithm

A self-tuning fuzzy PID (ST-FPID) control scheme is implemented within a joint interactive (Matlab/Simulink/Fluent) co-simulation framework for effective two degrees of freedom (2DOF) vortex-induced vibration (VIV) control of an elastically-mounted circular cylinder in laminar cross-flow of incompressible non-Newtonian power-law fluids based on the control action of a single transverse force actuator. The model-free controller, which systematically tunes the control parameters online in real time based on given rules, is well-known to be highly advantageous over the previously employed conventional PID controllers. It is particularly capable of handling the intricate non-linear dynamic effects inherent in the complex fluid rheology of non-Newtonian flow past the cylinder in presence of unmodeled system dynamics, high parametric uncertainties, diverse operational conditions, and time-varying external disturbances and control signals. Extensive numerical simulations reveal that the complex shear-thinning and shear-thickening behaviors of fluid viscosity can substantially influence the cylinder dynamic response, applied hydrodynamic forces, and flow structure. In particular, effectiveness and high performance of the adopted ST-FPID control strategy in substantial suppression of the high amplitude coupled 2DOF VIV of the elastically-mounted cylinder at selected critical reduced velocities in the lock-in region are established for a wide range of power-law index parameters (e.g., up to 83% reduction in RMS value of cylinder cross-flow displacement and up to 35% reduction in RMS value of cylinder in-line displacement for n=1and U* = 5 at Re = 100). Also, the vigorous action of the error-driven ST-FPID controller in forcing the high strength vortex shedding patterns of the uncontrolled cylinder out of the lock-in condition into the classical von Kármán vortex street of 2S-type mode of moderately weaker strengths is verified.

Investigation of nano-tribological behaviors and deformation mechanisms of Cu-Ni alloy by molecular dynamics simulation

With the rapid development of micro/nanodevices, it is critical to investigate and disclose the nano-sized tribological properties and deformation mechanisms. This paper aimed to understand nano-tribological behaviours and deformation process of Cu-Ni alloy. The effects of the pressed depth, alloy composition, and sliding distance on friction state, dislocation density, and von-Mises strain stress (VMSS) are comprehensively investigated using molecular dynamics simulation. The results indicate that a larger pressed depth brings about more lattice defects in the pressed region and a higher transverse force, the stacking fault and dislocation density increased rapidly as the Cu content increases, and a longer sliding distance results in more plastic deformation and the number of wear atoms generated. As the pressed depth and sliding distance rise, the plastic deformation and sub-surface damage are aggravated, however, Cu atoms improve the Cu-Ni alloy resistance of deformation. This work can enrich the understanding on the nano-tribological behaviour and deformation mechanism of Cu-Ni alloy during the ultraprecision process.