最新刊期
卷 47 ， 期 8 ， 2025
- 摘要：Aiming at the problem of the weld fatigue test of the new energy vehicle subframe, a program load spectrum compilation method based on the failure dominant load was proposed. Firstly, the finite element model of the rear subframe was established, and the stress distribution under unit load was coupled with the load of each connection point. The structural stress method was used to evaluate the fatigue life of the subframe welds, and six dangerous points that were easy to fail were selected. Secondly, by comparing the load damage of each connection point, the failure dominant connection point corresponding to the weld dangerous unit was determined. Then, the failure dominant load was determined by the principal stress analysis, time domain correlation and uniaxial damage contribution at the weld, so as to reduce the dimension of the multi-axial load and reduce the difficulty of the bench test loading. Finally, a pseudo-damage matrix was output based on the failure dominant load, the characteristic working conditions and their proportions were selected to obtain the load spectrum of the fatigue accelerated test program, and the minimum number of cycles was determined according to the principle of the damage equivalence. The numerical simulation results show that the program load spectrum can reproduce the damage of dangerous points and has a high acceleration coefficient, which verifies the effectiveness of the accelerated test spectrum.关键词：Rear subframe;Weld fatigue;Principal stress analysis;Failure dominant load;Characteristic working condition;Program load spectrum4|0|0更新时间：2025-08-18
- 摘要：Due to the needs of transportation, installation, grid connection, and maintenance, the construction of offshore wind farms in inshore areas often cannot be far from busy surrounding waterways, which significantly increases the probability of offshore wind turbines being impacted by ships. To analyze the performance and damage of different hollow ratios of protective devices when offshore wind turbines are hit by ships， the collision process of a 5000-ton bow-downward ship with an offshore wind turbine at a speed of 2.0 m/s was simulated using Ansys/Ls-Dyna. The influence of the hollow ratio on the anti-collision performance of Ogden rubber， Mooney-Rivlin rubber and Aluminum foam aluminum constitutive protective devices was studied and compared. The results show that with the increase of hollow ratio, the impact duration of aluminum foam protective devices increases, and the contact force decreases accordingly, while rubber materials show the opposite trend. As the hollow ratio decreases, the protective device is more similar to a solid tube, with a relatively smaller maximum indentation depth. Under the influence of hyperelastic properties, the indentation depth of rubber materials is smaller than that of aluminum foam after the collision is completed, and the material damage of the protective device is smaller. However, the proportion of internal energy in the support area gradually increases, so the influence of hollow ratio on the leg support needs to be considered in the design and research of protective devices.关键词：Offshore wind turbine;Hollow ratio;Collision;Crashworthiness2|0|0更新时间：2025-08-18
- 摘要：The main types of carbides in M50 bearing steel are MC, M2C and M23C6. Under the scanning electron microscopy (SEM), they exhibit significant differences in the shape, size, and distribution. Some carbides have larger sizes and uneven distribution. They become areas of stress concentration under loading， which has a negative impact on the bearing fatigue performance. So an improved mask region-based convolutional neural network (Mask R-CNN) model was proposed which can batch identify the types of three kinds of carbides in SEM pictures, the diameters of carbides were measured, and the distribution of carbides was showed. The output images and histogram results show that the size of M2C carbide in M50 bearing steel is large and unevenly distributed, but the distribution of MC carbide with the largest size and M23C6 with the smallest size is reasonably uniform.关键词：Deep learning;Mask R-CNN;M50 bearing steel;Carbide2|0|0更新时间：2025-08-18
- 摘要：In order to improve the high temperature wear resistance and extend its service life of 304 stainless steel, the high temperature wear-resistant NiCrAlY/Co coating was prepared on the surface of 304 stainless steel by the laser cladding.The morphology, phase composition and microhardness of the coating were analyzed.The tribological properties of 304 stainless steel and NiCrAlY/Co coating at different temperatures（the room temperature to 800 ℃) were studied, and the wear mechanism was analyzed.The results show that the coating is metallurgically bonded to the 304 stainless steel substrate; the coating is mainly composed of γ-Co,(Cr, Ni) and AlNi3 phases; the average microhardness of the coating（303 HV) is about 1.6 times that of the substrate（194 HV); Compared with the substrate, the coating has a smaller friction coefficient at 200-600 ℃, the friction coefficient is comparable at 800 ℃, and the lowest friction coefficient of the coating is 0.5 at 600 ℃.The wear rate of the coating from the room temperature to 800 ℃ is lower than that of the substrate，and the lowest wear rate is 1.91×10-5 mm3/(N·m) at 400 ℃, which is about 1/3 of the substrate, indicating that the NiCrAlY/Co coating improves the high temperature wear resistance of 304 stainless steel. At medium and low temperatures， the wear mechanism of the substrate is mainly abrasive wear and adhesive wear, and the wear mechanism of the NiCrAlY/Co coating is mainly abrasive wear and gradually slight adhesive wear.At 800 ℃, the wear mechanism of the substrate is plastic deformation, and the wear mechanism of the coating is oxidation wear.关键词：304 stainless steel;Laser cladding;NiCrAlY/Co coating;High temperature tribological properties2|0|0更新时间：2025-08-18
- 摘要：Shot peening process is widely used in the manufacturing process of gears and other basic components, and its own limitations limit the enhancement of the surface integrity of the workpiece. In order to further improve the surface integrity of the workplece, A combination of numerical simulation and experimental methods was utilized to study the effect of two surface composite strengthening processes, such as double shot peening and shot peening-ultrasonic rolling, on the surface integrity of 18CrNiMo7-6 carburization gear steel samples, and mainly analyzed the effect of the two composite strengthening processes on the improvement of surface integrity of the shot peened samples. The results show that the maximum value of the residual compressive stress of the double shot peening sample was 1 359.56 MPa, locates at the depth of 0.08 mm, and the maximum value of the residual compressive stress of the shot peening-ultrasonic rolling peening sample was 1 329.05 MPa, locates at the depth of 0.25 mm. Compare with the single shot peening sample, the surface roughness of the double shot peening sample and the shot peening-ultrasonic rolling sample was 29.42% and 29.42% lower than that of the single shot peening sample. Compare with the single shot peening samples， the surface roughness of the double shot peening samples and shot peening-ultrasonic tumbling peening samples decreased by 29.42% and 62.76%， respectively, the surface microhardness increased by 8.70% and 17.60%, and the standard deviation of the surface node compressive residual stress value decreased by 23.36% and 89.50%. The shot peening-ultrasonic rolling process is more effective in enhancing the surface hardness, thickness of the residual stress layer and uniformity of the residual compressive stress, as well as reducing the surface roughness of the specimens， and can effectively improve the surface integrity of the shot peened samples.关键词：18CrNiMo7-6 steel;Shot peening;Ultrasonic rolling;Surface integrity47|108|0更新时间：2025-08-18
- 摘要：Minimal surfaces are characterized by spatially continuous smoothness, which can effectively avoid the problem of the stress concentration, and have become a significant focus in the research of mechanical metamaterials. A Scherk single-periodic minimal surface (SPMS) was studied, and the spatially continuous smooth geometrical model was generated using a voxel reconstruction technique with multi-software association method. The mechanical behavior and energy absorption characteristics of the single-period Scherk surface structure were investigated using finite element simulation. The impact of the mathematical parameters of the minimal surface on the geometric configuration was examined. Five minimal surfaces with different parameters were established, and the deformation patterns and stress distributions of the five structures were explored under positive and lateral compression conditions. The Scherk surface structures were fabricated by metal printing technology, and quasi-static compression tests were conducted. The results show that the Scherk single-period surface has an obvious negative Poisson ratio effect, and the SPMS structure exhibits X-and V-shaped deformation modes, which can well withstand the external loading effects. The compression tests show the hump phenomenon of the reaction force and displacement curves of the SPMS structure, indicating that the structure has a negative Poisson ratio and negative stiffness property. This property provides a wide space for its application research in large deformation damage and structural energy absorption.关键词：Single-periodic minimal surface;Sherk surface;Energy absorption;Negative Poisson ratio;Negative stiffness2|0|0更新时间：2025-08-18
- 摘要：In pressurized-water reactor nuclear power plants, the vessel nozzles of large carbon steel equipment such as reactor pressure vessel (RPV), steam generator (SG), and main pumps are connected to austenitic steel pipes through dissimilar metal welds (DMWs). The thick-walled DMW has material inhomogeneity and complex weld residual stress (WRS), which easily leads to the generation of fatigue or stress corrosion cracks.Firstly, the WRS of DMW in nuclear power plants obtained through international measurements and numerical analyses was investigated. Then, based on a rapid WRS simulation method for volume uniform heating of unit cells, the WRS of DMW in the hot leg of the primary loop (the connecting pipe section from RPV outlet to SG inlet, which is the pipe section with the highest operating parameters in the primary loop pressure boundary) was obtained.The numerical simulation results are consistent with the trend of the fitting envelope curve recommended by the United States, and the overall results can be enveloped by the fitting curve recommended by the United States, indicating that the described rapid WRS simulation method is feasible. The WRS of thick-walled DMW is relatively high, and the stress values at the inner and outer surfaces of the pipe are more conservative than the recommended values of the United States, suggesting that more safety margins can be obtained in actual structural analyses.关键词：Pressurized-water reactor;Dissimilar steel weld;Weld residual stress;Numerical simulation2|0|0更新时间：2025-08-18
- 摘要：To study the response characteristics of the hollow extruded profile of the vehicle after the collision, the generalized incremental stress state-damage model (GISSMO) was introduced and the finite element simulation was carried out. Firstly, based on the test results of 6082-T6 aluminum alloy, the dynamic and static mechanical properties and fracture behavior under different stress states were characterized by the modified Johnson-Cook (MJC) model and DF2016 model respectively. Secondly, the parameter calibration of GISSMO was carried out based on the combination of LS-OPT soft ware and manual optimization. Then, according to the mesh size effect, the mesh size dependence correction was carried out, and the effectiveness of the model and correction were verified by comparison between the experiment and simulation. Finally, the impact simulation analysis of a hollow extruded profile on the side wall of a vehicle body was carried out, and the impact of material damage and fracture on the simulation results was compared. The results show that GISSMO can more accurately reflect the response of profiles under longitudinal impact than without considering the damage and fracture of materials.关键词：GISSMO;Mesh size effect;Hollow extruded profiles;Collision behavior2|0|0更新时间：2025-08-18
- 摘要：In practical operation, the loads borne by electric excavators often exhibit significant non-stationary random characteristics, leading to complex vibration phenomena of the battery pack, which directly affects the safe and reliable operation of the battery pack. To address this issue, the characteristics of road excitation, plunger pump pressure pulsation excitation, and impact excitation on electric excavators under complex working conditions were investigated. The vibration transmission paths under various excitations were analyzed, a dynamic model of the battery pack was established, the vibration characteristics of the battery pack under non-stationary random excitation were revealed, and case studies were conducted for analysis and verification. The research shows that reconstructing road excitation signals based on wavelet transform and Grey Wolf Optimization-Variational Mode Decomposition (GWO-VMD) signal analysis algorithm can effectively reflect the characteristics of road excitation. The road excitation borne by electric excavators under driving conditions exhibits significant non-stationary characteristics. Under non-stationary random excitations such as road excitation, the battery pack of electric excavators produces complex and changeable vibrations, whose power spectral density of dynamic response changes significantly with time, showing obvious non-stationary random characteristics.This study provides a reference for the safe and reliable operation of battery packs in electric excavators.关键词：Electric excavator;Battery pack;Non-stationary;Random excitation;Vibration characteristic2|0|0更新时间：2025-08-18
- 摘要：Aiming at the problems of traditional impact load identification methods, such as the requirement for a large number of sensors, high sampling frequency, and low identification accuracy, a new impact load identification method based on empirical mode decomposition (EMD) technology was proposed.The EMD technology was used to decompose the complete impact response to obtain the modal acceleration response. The impact location was quickly realized by measuring the collinearity between the uncorrected mode shape vector and the column vector of the mode shape matrix in the modal acceleration response. According to the positioning results, an optimization objective function was constructed. The time history of the impact load was fitted by using the Gaussian basis function, and the optimal fitting parameters were quickly solved by using the two-dimensional gradient descent method.Tests conducted on a cantilever plate with dimensions of 600 mm×200 mm×3 mm show that with only one accelerometer, the success rate of 36 impact positioning tests is 91.67%. The peak relative error and relative error index of the reconstruction results are less than 10% and 40%, respectively.关键词：Impact load identification;Empirical mode decomposition;Modal acceleration response;Uncorrected mode vector;Basis function fitting2|0|0更新时间：2025-08-18
- 摘要：Aiming at optimizing the gear surface modification process, the influence of ion nitrogen implantation on the bending fatigue strength of carburized and quenched gears was studied.Using low-carbon alloy steel 18CrNiMo7-6 carburized and quenched gears as the matrix, nitrogen ion implantation treatment was carried out through a radio-frequency plasma-assisted ion implantation system. The root metallography, hardness gradient, residual stress distribution, and bending fatigue properties of ion-implanted gears and unimplanted gears were systematically compared. The results show that the ion nitrogen implantation process increases the root hardness from 695 HV0.1 to 780 HV0.1, an increase of 12.2%; the hardened layer depth decreases from 1.50 mm to 1.41 mm, a reduction of 6.0%; and the surface residual stress decreases from -400 MPa to -286 MPa, a reduction of 28.5%. Based on the R-S-N equation fitted by bending fatigue tests, under 99% reliability, the fatigue life of ion-implanted gears is only 12.3%-19.3% of that of the control gears, with the failure mode dominated by brittle fracture and accelerated crack propagation rate. The study indicates that although ion nitrogen implantation can delay crack initiation through surface strengthening, the excessively shallow hardened layer and reduced residual stress lead to insufficient crack propagation resistance, ultimately weakening the bending fatigue life of gears.关键词：Nitrogen ion implantation;Gear bending fatigue;Fatigue life;Residual stress2|0|0更新时间：2025-08-18
-
RESEARCH ON RESPONSE CHARACTERSTIC AND DYNAMIC MODELING OF LAUNCH VEHICLE UNDER THE COLD LAUNCH MODE
摘要：To accurately simulate the complicated load transfer pattern of the launch device under cold launch mode, the rigid-flexible coupling dynamic simulation method was adopted to analyze the dynamic response of a launch vehicle, the structural strength was also verified. The finite element flexible body was introduced and a multi-rigid-flexible-body dynamic simulation model of a launch vehicle was constructed. Accuracy of the model was verified by the actual launch test. The influence law between the vibration response and stress state of the launch vehicle and the launch angle was further analyzed. The results show that amplitudes of the transmitted load and stress inside the launcher will reduce when the launch angle is close to 90°. The modeling and analysis approaches proposed in this study can effectively support the optimal design of the launch device.关键词：Cold launch;Launch vehicle;Multi-rigid-flexible-body dynamic;Simulation;Vibration2|0|0更新时间：2025-08-18 - 摘要：In order to study the strain softening phenomenon of ultra-fine grain (UFG) metal materials under uniaxial tensile loading, a modified model considering the effect of residual internal stress was proposed based on the classical crystal plasticity constitutive model, and the specific form of residual internal stress and its evolution were programmed into the user subroutine. The uniaxial tensile test data were fitted to verify the validity of the model, and the finite element simulation results of crystal plasticity were compared with and without the residual internal stress. The results show that the simulation results obtained by using the modified crystal plasticity constitutive model are in good agreement with the experimental results, indicating that the modified crystal plasticity constitutive model can effectively capture the strain-softening phenomenon of UFG metal materials, and the simulation results show different properties under the two conditions whether the residual internal stress is taken into account. It is reasonable to explain the strain softening phenomenon of UFG metal materials from the perspective of the formation and action of residual internal stress.关键词：Ultra-fine grain metal materials;Crystal plasticity constitutive model;Uniaxial tension;Strain softening effect;Residual internal stress2|0|0更新时间：2025-08-18
- 摘要：The harsh operational environment of helicopters renders their structures highly susceptible to the initiation and propagation of hole-edge cracks around bolt holes, thereby compromising structural integrity and load-bearing capacity. To monitor hole-edge cracks in helicopter attachment lug structures, piezoelectric guided wave-based structural health monitoring (SHM) techniques are commonly employed. However, due to the difficulty in detecting small cracks at the early stages of propagation and the presence of large through-hole configurations in attachment lug structures, the accuracy of guided wave monitoring remains suboptimal. Therefore, addressing the accuracy issues in crack monitoring of attachment lug structures, this study proposes a piezoelectric guided wave array-based method for hole-edge crack detection. Firstly, damage feature information was extracted from acquired piezoelectric guided wave array signals encompassing the entire sensor network. Subsequently, a damage alarm threshold was established using a mean-value method to facilitate damage detection. Furthermore, an improved delay-and-sum imaging algorithm was developed based on the specific configuration of the attachment lug structure to optimize probability distribution and achieve precise crack localization. Finally, validation was conducted through test monitoring of crack propagation in attachment lug structures. Test outcomes demonstrate that the proposed method enables accurate alarm triggering and localization of hole-edge cracks around bolt holes, with localization errors confined within 2.01 mm, thereby confirming the efficacy and precision of the proposed approach.关键词：Key attachment structure;Hole-edge crack monitoring;Piezoelectric guided wave;Damage alarm;Damage location13|5|0更新时间：2025-08-18
- 摘要：To address the issue of accuracy degradation caused by aerodynamic damping when measuring the moment of inertia of irregular specimens with large airfoil surfaces using the torsional pendulum method, a compensation approach based on drag simulation results was proposed. Initially, the mechanism of aerodynamic damping in torsional oscillations was analyzed, and a measurement model incorporating compensation through calculation of aerodynamic damping torque was established. Subsequently, the reduced frequency parameter was introduced to characterize the unsteady aerodynamic nature of the aerodynamic damping torque. By employing a quasi-steady assumption combined with equivalent linearization techniques, the unsteady time-varying aerodynamic damping torque was equivalently represented as viscous damping. Furthermore, computational fluid dynamics (CFD) simulations were conducted to obtain drag coefficients during specimen motion, from which a compensation formula based on drag coefficients was derived. Finally, validation test were designed and performed to verify the proposed method. The findings indicate that under low reduced frequency conditions (reduced frequency less than 0.01), the relative error between the equivalent aerodynamic damping ratio calculated via quasi-steady assumption and test separation values is approximately 7%. After compensating using the proposed equivalent aerodynamic damping ratio, the error between measured and theoretical moments of inertia is approximately 0.2%, demonstrating that the proposed method effectively enhances measurement accuracy for moments of inertia of irregular specimens with large airfoil surfaces.关键词：Moment of inertia measruement;Aerodynamic damping;Irregular specimen;Unsteady aerodynamic force;Drag coefficient13|29|0更新时间：2025-08-18
·Experimental Research·Testing Technology·
- 摘要：In order to ensure the industrial robot realizes the reliability goal, reliability allocation is a task to be accomplished in its manufacturing design stage. According to the characteristics of industrial robots, such as complex structure, high uncertainty, few samples, and failure correlation between component parts, a reliability allocation method for industrial robot systems based on BP neural network and Pythagorean fuzzy numbers was proposed. Using Copula function to establish a system reliability model, the failures of industrial robots were classified into three levels, the system level, the subsystem level, and the component level. By using the back propagation (BP) neural network, the system reliability, subsystem structure importance and subsystem complexity were taken as the input variables to complete the system-to-subsystem reliability allocation. The Pythagoras fuzzy number was introduced to score the influence factors of importance, environmental condition, technical level, maintainability, cost sensitivity and complexity, complete the reliability allocation from the subsystem level to the component level.The results show that the methodology achieves reliability goals and ensures reliability growth.关键词：Reliability allocation;Industrial robot;Copula function;BP neural network;Pythagorean fuzzy number2|0|0更新时间：2025-08-18
- 摘要：Aiming at the problem that loop-end braided stents are prone to loop-end fracture during crimping, the key design parameters affecting the structural stability of loop-end braided stents were explored, and an improvement scheme was proposed.Numerical simulation of crimping for magnesium alloy loop-end braided stents was conducted using Abaqus analysis software. The results showed that increasing the braiding angle can effectively reduce the risk of loop-end fracture. Based on this finding, a variable pitch stent was designed, which features increasing the braiding angle at both ends to form sparse segments while maintaining the braiding angle in the middle of the stent. The influence of adjusting the length and braiding angle of the sparse segments on the mechanical response of the stent was evaluated.The research results showed that increasing the braiding angle and length of the sparse segments can effectively reduce the axial elongation and loop-end stress of the stent, but it will shorten the length of the middle dense segment, thereby reducing the radial force of the stent. Different from the flared expansion of the constant pitch open-end stent, the variable pitch stent presents a shape with large middle expansion and small end expansion after expansion.This study reveals the potential of variable pitch design in controlling loop-end fracture and provides a reference for the structural optimization of magnesium alloy braided stents.关键词：Finite element analysis;Braided stent;Magnesium alloy;Loop-end design;Variable pitch design2|0|0更新时间：2025-08-18
- 摘要：Aiming at the issues of fracture and weight reduction in the wheel hub motor housing of an off-road vehicle, a structural strength finite element simulation analysis and structural topology optimization design were conducted. Firstly, a multi-body dynamics model of the entire vehicle was established, and a simulation analysis was performed to determine the load boundary conditions of the hub motor housing. Secondly, based on the spatial position relation between the housing and interconnected structures, a finite element model of the motor housing and suspension system was constructed for dynamic simulation analysis. Subsequently,using the OptiStruct software platform,with the objective of minimizing structural compliance and constraints on volume ratio before and after optimization as well as the maximum stress, a mathematical topology optimization model for the motor housing under various typical operating conditions was established and solved to obtain the optimal material distribution scheme. Finally, the optimization results were verified by simulation. The results indicate that compared to the existing design,the optimized hub motor housing structure experiences a stress reduction of over 40% and a weight reduction of 2.6%. It addresses the original fracture issue and eliminates the phenomenon stress concentration, thus providing the valuable reference for the design of similar hub motor housing structures.关键词：Off-road vehicle;Hub motor housing;Finite element simulation;Topology optimization;Lightweight design3|0|0更新时间：2025-08-18
- 摘要：The telescopic arm, a pivotal component in the pipeline grabbing vehicle, links the lifting platform and the mechanical claw, shouldering the majority of the load. Conducting a reliability analysis is imperative. Traditional methods for reliability face challenges like high computational costs and low accuracy dealing with multidimensional uncertainties. To overcome these, our study proposed an engineering mechanical reliability analysis method, leveraging Adams dynamic simulation, semi-supervised learning, deep neural networks, and Monte Carlo method. In this study, a virtual prototype model of the pipeline grabbing vehicle was established, identifying hazardous operating conditions. Combining the telescopic arm model’s geometric parameters and overall structure, uncertain factors influencing the maximum von Mises stress were determined, conducting a sensitivity analysis was conducted. Utilizing optimal Latin hypercube sampling based on uncertain parameter distributions, Ansys Workbench was employed to build a finite element model, obtain output results for the sample size. Semi-supervised learning processed the finite element simulation data, enhanced deep neural network training accuracy. Finally, based on the fourth strength theory, a failure criteria for the telescopic arm component was determined. Combining deep neural networks and Monte Carlo method, the reliability and failure probability were predicted. Results show that this method surpasses actual engineering precision requirements， provides a certain guiding significance.关键词：Telescopic arm;Reliability analysis;Semi-supervised learning;Deep neural networks;Optimal Latin hypercube sampling2|0|0更新时间：2025-08-18
- 摘要：This article took the folding section cam linkage mechanism of a carton folding machine as an example. Firstly, a preliminary design of the cam was carried out based on actual working conditions. Then, combined with the analytical method designing the cam mechanism based on the allowable pressure angle of the cam, a mathematical model was established with the swing rod angle and the center distance between the cam and the swing rod as design variables. Using the NSGA-Ⅱ optimization algorithm, perform multi-objective optimization design on the cam linkage mechanism and select the optimal solution from the generated Pareto solution set. Based on the optimization results, the preliminary design of the cam linkage combination mechanism was adjusted, and the contour of the cam was obtained through Matlab programming, verifying that the optimized cam pressure angle met the allowable pressure angle. Finally, simulation analysis was conducted on the optimized cam linkage mechanism using Adams software. It is found that the displacement, velocity, and acceleration of the blade movement meet the design requirements, verifying the correctness and feasibility of the optimization results. At the same time, it also provides a reference method for the optimization design of other cam linkage mechanisms.关键词：Cam linkage mechanism;Allowable pressure angle;NSGA-Ⅱ optimization algorithm;Multi objective optimization;Simulation analysis2|0|0更新时间：2025-08-18
·Optimization·Reliability·
- Technical support is provided by Beijing Founder electronics co., LTD 豫ICP备05013835号-4
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0