Section Of Diagram Research Articles

Phase equilibria in the ZrO2–YO1.5–NbO2.5 system at 1300°C and high‐temperature experiments in the ZrO2–YNbO4 subsystem

AbstractPhase equilibria in the ZrO2–YO1.5–NbO2.5 system were experimentally studied at 1300°C, and a comparison with the existing ZrO2–YO1.5–TaO2.5 (ZYTO) was conducted. Ternary fluorite phases on the Y:Nb > 1 side extend from binary ZrO2‐YO1.5 to YO1.5–NbO2.5 system, generating a continuous solid solution region. Furthermore, it was observed that three phases of M‐YNbO4, fluorite, and m‐ZrO2 were in equilibrium. On the Y:Nb < 1 side, two three‐phase equilibrium regions were measured, namely M‐YNbO4+m‐ZrO2+O‐Nb2Zr6O17 and h‐Nb2O5+O‐Nb2Zr6O17+M‐YNbO4. The tetragonal YNbO4 and ZrO2 phases both extend nearly along with Y:Nb = 1. The t‐ZrO2 phases with slightly lower stabilizer content were found to transform into their monoclinic polymorph during the cooling process. However, in the ZrO2–YNbO4 subsystem, the tetragonal ZrO2 was nontransformable due to larger YO1.5 and NbO2.5 co‐dopants, and the maximum solubility is about 18.1 mol%. Upon cooling, the tetragonal YNbO4 phase, even with the maximum ZrO2 content, is transformable to monoclinic form. The maximum solubility of ZrO2 in YNbO4 is determined to be about 20.7 mol%. Finally, the high‐temperature liquidus in the ZrO2–YNbO4 system was first determined based on the cooling traces, and a vertical section diagram was proposed for further speculation. A eutectic reaction of Liquid→YNbO4+ZrO2 was discovered, and the eutectic composition and temperature were measured as 39.2ZrO2–29.2YO1.5–31.6NbO2.5 and 1813°C. This study provides the basis for thermodynamic assessment of ZrO2–YO1.5–NbO2.5 and is valuable for the design and development of the ZrO2–YO1.5–NbO2.5‐based ceramic materials.

Mathematical modeling of sound propagation through the respiratory tract in a modified gas environment

The aim of the work was to develop a mathematical model of sound propagation through the human respiratory tract when breathing certain respiratory gas mixtures. We based the model on an assembler model of branching of the respiratory tract. For calculations, we presented the human tracheobronchial tree in the form of an equivalent T-shaped cut section diagram, which includes parameters of the walls of the respiratory tract. We carried the simulation out in two main stages. At the first stage, we calculated the impedance of the flow from the small airways to the larger airways. At the second stage, we calculated the sound pressure caused by breathing. As a result, we obtained the curves of the impedance dependence on the frequency spectrum, as well as the sound power from the respiratory flow. We noted that when breathing air, the impedance value remains constant with increasing frequency. Moreover, we also noted that when exposed to a heavier gas than air, the impedance value constantly increases, and when exposed to lighter gases, after reaching a maximum, the impedance value decreases. We found that the highest sound pressure is typical for the oxygen-krypton mixture, and the lowest for the oxygen–helium mixture. We also found that in the case of modeling the laminar flow regime (with a critical Reynolds number equal to 1800), sound affects how many generations of bronchi more than in the case of modeling the transient flow regime (with a critical Reynolds number equal to 2700). Thus, we drew conclusions about the influence of the physical properties of gaseous media on the amount of sound pressure and the propagation of sound through the human respiratory tract.

Nonlinear dynamics of planetary roller screw mechanism.

The synchronous meshing of the gear pair and the screw pair is a typical feature of the planetary roller screw mechanism. In order to fully derive and analyze the nonlinear dynamic characteristics of the system, this paper creatively incorporates the time-varying meshing stiffness of gear pair and the comprehensive transmission error into the research content. Combined with the thread contact force and friction force between the roller and the screw and between the roller and the nut, the nonlinear dynamic model of the planetary roller screw mechanism considering the meshing excitation of the gear pair is established. According to the time domain diagram, frequency domain diagram, phase plane diagram, Poincaré section diagram, three-dimensional spectrum diagram, and spatial phase diagram, the nonlinear behavior of the system is described in detail, and the bifurcation evolution process of the system under the excitation frequency parameters of the external load is revealed. In addition, based on the theory of multi-scale method and considering the variables such as meshing stiffness, meshing damping, and load fluctuation, the stability equation of the primary resonance of the system is derived. The analysis of the stability of the system under different working conditions shows that the parameters are selected within a reasonable range, which effectively reduces the primary common amplitude value and enhances the overall stability of the system. The research content improves the previous system dynamics modeling method and provides a theoretical basis for the nonlinear dynamics modeling method and parameter optimization design of the planetary roller screw mechanism.

On formation, annihilation, and evolution of potential wells, and nonlinear phenomena of multi-magnet energy sink system.

This paper investigates the formation, annihilation, and evolution mechanisms of potential energy wells in nonlinear energy sink systems. The nonlinear energy sink system is composed of multiple inner and outer magnets. Two multi-magnet energy sink (MES) architectures are designed: a single-magnet vibrator and a double-magnet vibrator. Multi-stable (bi-, tri-, quad-, penta-, hexa-, and hepta-stable) mechanisms are elaborated by the Poincaré section and bifurcation diagram concerning the magnet length, the link length, and the MES configuration. The results show that the change in the internal structural parameters of the MES system will generate different types of bifurcations (i.e., saddle-node, subcritical, and super pitchfork bifurcations) and phase trajectories and have rich nonlinear response behaviors in the low frequency and wide frequency range, which can be used for damping and vibration reduction of engineering structures, vibration control, and energy source of the microgrid.

Bifurcation analysis, quasi-periodic and chaotic behavior of generalized Pochhammer-Chree equation

We take into account the bifurcation analysis of the generalized Pochhammer-Chree (PC) equation that describes the dynamics of several systems in science and engineering. The considered model is changed into a planar dynamical system by applying the Galilean transformation. The phase portraits are plotted by considering suitable values of the bifurcation parameters. The considered model is solved using the RK method to compute the supernonlinear and nonlinear wave solutions. All phase portraits and wave solutions are depicted in the phase plane by simply fixing the relevant parameters values. The equilibrium points are obtained, and the same are classified. Moreover, sensitive analysis for different initial value problems is applied to analyze the quasiperiodic, chaotic behavior and time series after introducing an extrinsic periodic perturbation term. In addition, the Lyapunov characteristic exponents, Poincare section and bifurcation diagrams are also discussed to examine the chaotic pattern of the model. Numerical simulation results show that changing the frequencies and amplitude values impacts the dynamical features of the considered model.

Calculation and Experimental Verification of Zn–Al–Mg Phase Diagram

The liquid phase projection diagram, three-dimensional phase diagram, and vertical section diagram of the Zn–x%Al–x%Mg alloy system was calculated using the phase diagram calculation software Pandat. Simultaneously making full use of the self-developed hot-dip galvanizing process simulation machine by China Steel Research produced a 75%Zn–19%Al–6%Mg coating. A method combining phase diagram calculations and experimental verification was used to investigate the equilibrium phases and solidification process of the alloy. The microstructure of the 75%Zn–19%Al–6%Mg coating was studied using scanning electron microscopy and energy dispersive spectrometry. The results indicate that the coating structure consists of primary Al dendrite phase, MgZn2 inter-metallic compound and Zn-rich phase. There is no ternary eutectic structure in the coating structure. Al dendrites grow on the surface of the coating, while there are no Al dendrites on the cross-section. The experimental results strongly concur with the calculated results from the Pandat phase diagram. The solidification sequence of the 75%Zn–19%Al–6%Mg coating is L→L + Al→L + Al + MgZn2→Al + MgZn2 + Zn. The phase diagram guides industrial production significantly, avoiding the waste of transitional materials and zinc caused by small scale trial and error experiments, thus reducing unnecessary production costs. The factory can select a reasonable coating composition designing scheme in the phase diagram, based on the performance requirements of customers for the coating.

Геоінформаційна система інженерних мереж та комунікацій морського торгового порту

The work is devoted to researching the process of development, implementation and operation of the geoinformation system of engineering networks and communications (GISIS) in the Odesa Sea Trade Port. The beginning of the development of the system began more than twenty years ago. The beginning of the works was preceded by the stage of pre-project studies, the result of which were the technical tasks for the implementation of the works and the project of the structure of information support. The work was carried out in stages, which corresponded to a separate territory and type of work. The purpose of this work is to research the processes of performing field and camera geodetic, photogrammetric, cartographic works, designing and creating a geoinformation database, selecting and adapting specialized geoinformation software, operating and supporting the system during the full life cycle of the geoinformation system. The methodology mainly corresponds to the following algorithm of work performance. At the stage of preliminary design studies: – collection and analysis of data on the exchange of cartographic and analytical information between external organizations, – collection and analysis of data on the exchange of cartographic and analytical information within the enterprise, primarily between engineering services, – description of the existing document circulation system with cartographic and analytical information, – a description of the shortcomings of the existing document management system, – determination of requirements for geo-information software and justification of the configuration of the geo-information software package and its architecture. At the stage of field work: – construction of a shooting justification and definition of data for communication with other coordinate systems, – reconnaissance on the territory of performance of works. Planning field work. – execution of topographical and geodetic works for the purpose of building or updating 1:500, 1:2000 scale plans. Construction of outlines. – performance of engineering and geodetic works for the study of underground communications in order to design the sections of wells and other engineering nodes. At the stage of design (camera works): – based on outlines and electronic survey protocols, development or correction of 1:500, 1:2000 scale plans using geoinformation software. – based on outlines, photofixation materials, construction of diagrams of sections of wells and other engineering nodes in electronic form. – formation of a geo-informational database of the object on the territory of execution of works. – debugging the project in the environment of geoinformation software. – coordination of the project with the engineering services of the enterprise and external organizations. – commissioning the developed project to the customer. Scientific novelty and practical significance – for the first time, research and development of the methodology of creation and support at all stages of the life cycle of the geoinformation system of engineering networks and communications of a large seaport was carried out. The methodology was developed for a long time during the entire life cycle of the system. The methodology was used by other ports and large industrial enterprises.

An Experimental Electronic Board ADF339 for Analog and FPGA-Based Digital Filtration of Measurement Signals

This work introduces and examines a new programmable electronic system, Board ADF339, designed for filtering analog measurement signals of low frequencies. The system operates in a mixed mode in collaboration with a digital controller implemented on the myRIO-1900 FPGA module. It enables the digital selection of the type and frequency settings of the UAF42 integrated circuit. In the technical implementation section, electronic filter and phase shifter circuit diagrams are presented, along with the digital counterpart of the analog filter. Tests of this system were conducted on signals generated using a function generator, which was followed by the filtration of signals occurring in real laboratory setups. A series of real responses from three different laboratory systems and a measurement system utilizing LabVIEW FPGA virtual instruments are demonstrated. After computing SNR indicators for noisy waveforms, the application scope and usability of the board are highlighted.

Prestress analysis and geometry optimization for conical cable domes with zero Gaussian curvature

The conical cable dome with a rotating cone and zero Gaussian curvature is a new type of cable dome with the generatrix that follows a straight line. The paper studies the prestress design and mechanical properties of such cable domes. First, on the basis of the section and vertical diagrams of the proposed cone, a simplified method is developed to calculate feasible prestresses of cables and struts using the principle of nodal balance. Second, prestress distribution, load-bearing capacity, and prestress of the conical cable domes with 15 different combinations of rise-span ratio and inner triangular slope under both prestress and load states are studied. Additionally, the paper proposes five load conditions to assess the performance of the conical cable domes. Finally, the total strain energy, basic frequency, radial reaction, and gravity are optimized through single-criterion and multi-criterion based on the combination of a genetic algorithm and the Newton iteration method. To keep the outer appearance of the conical cable dome, the work selects the strut length as the optimization variable. An optimized conical cable dome is recommended with a low prestress uniformity index and high uniformity index. The results indicate that the conical cable dome is sensitive to the asymmetrical loads, especially the wind loads. For the single-criterion optimization, the structure with the basic frequency under loads as the objective function has the best load-bearing capacity. After optimization, the maximum nodal displacement is 32% and 43% of the original one under LC4 and LC5. Besides, to get a synthetic optimization result, a multi-criterion optimization is suggested.

Analysis of vibration characteristics of face gear powering-split transmission system

A nonlinear dynamic model of the face gear powering-split transmission system was established, and the nonlinear dynamic characteristics of the face gear powering-split transmission system were studied by considering various factors such as support stiffness, time-varying meshing stiffness, lateral clearance of teeth, comprehensive transmission error and bearing stiffness. The Runge–Kutta integral method is used to solve the differential dynamics of the system. The nonlinear behavior of the system is described by the phase plane diagram, time history diagram, frequency domain diagram, and Poincare section diagram. The influence of external excitation frequency on the nonlinear behavior of the system is described by the bifurcation diagram. In addition, the multi-scale method is used to analyze the superharmonic resonance of the system and determine the stability conditions of the superharmonic resonance of the system. The influence of meshing damping, time-varying meshing stiffness, and time-delay control parameters on the amplitude-frequency characteristics of the system is studied by numerical analysis of the superharmonic resonance. The results show that the system will show periodic chaotic alternating motion characteristics under external excitation. Selecting meshing damping, meshing stiffness, and time delay control parameters in a reasonable range can effectively reduce the superharmonic co-amplitude and keep the system in a stable state.

The Application Research of BIM Technology in the Construction Process of Yancheng Nanyang Airport

The application of BIM technology in building construction provides the possibility to realize design accuracy, to visualize the construction details, to optimize construction schemes, and to enhance cooperation among various professionals. The Yancheng Nanyang Airport terminal 2 project, with its large span of steel roof structure, complex installation in mechanical and electrical pipeline (MEP) engineering, and difficulty in construction organization, is taken as the engineering background. The whole process application of BIM technology in the construction process is introduced. In structural engineering construction, the application of BIM technology can provide guidance for plane layout of the construction site, and can also assist in deepening the designs of irregular steel components. In steel construction, the application of BIM technology gives a commendable visual demonstration of the construction process of the metal roof system and the single-layer reticulated shell. In MEP engineering, the application of BIM technology provides a great approach to establish a synthesis of pipeline drawings to further form pipeline section diagrams and operation drawings. By integrating the dimension of time, precision control, and deviation rectification, a recursive construction drawing can be built. With respect to synergistic management, the quality and safety management in the construction site can be implemented on the basis of BIM terminal equipment as well. This paper will give a great reference on the application of BIM technology in the airport terminal construction.

CALPHAD-guided design of Mg-Y-Al alloy with improved strength and ductility via regulating the LPSO phase

This work performed a CALPHAD-guided design strategy to develop high strength-ductility Mg–Y–Al alloy by taking advantage of the strengthening effect of the LPSO phase and the ductilizing effect of the α-Mg matrix. To achieve this goal, the LPSO phase content and the Y content in the α-Mg matrix were quantitatively optimized via calculations of the isoplethal section and phase fraction diagrams. Based on this, three typical Mg-Y-Al alloys without the LPSO phase and with varying LPSO contents were designed. The strength of the alloys was significantly improved by the introduction of the LPSO phase and the increase in its content. However, the ductility of the alloy was maintained while increasing the LPSO content. Through analyzing the strengthening and ductilization mechanisms, it was revealed that the LPSO phase can strengthen the extruded alloys by refining the dynamic recrystallized grain size, exerting a short-fiber-like strengthening effect, and dislocations strengthening effect by hindering <c+a> dislocations movements. The ductile α-Mg phase with considerable Y content can effectively withstand plastic strain by operating multiple slips during the deformation, significantly improving the ductility of the material. The results of this study inspired the development of an effective design strategy to produce high strength-ductility Mg-Y-Al alloys by quantitatively optimizing the LPSO phase and Y contents in the α-Mg matrix, as well as to design high-performance Mg alloys for engineering demands in the future.

Analysis of the Dynamic Characteristics of a Gear-Rotor-Bearing System with External Excitation

The dynamic response of the rotor system in a ring die granulator is complex and difficult to solve when it operates under joint external, support and gear mesh forces. To solve this problem, a finite element method and extrusion theory was applied in this study to develop a dynamic coupling model for a hollow overhung rotor with external load excitation. A Newmark-β numerical integration method was used to solve for the dynamic response of the overhung rotor under multiple excitation forces. The results included time-domain response diagrams, frequency-domain response diagrams, phase diagrams, Poincaré section diagrams, and bifurcation diagrams. The model and the method were verified by testing a ring die granulator. On this basis, the dynamic response of the system is predicted according to the influence of different parameters. As the bearing support distance increased, the roller eccentricity decreased, the bearing clearance decreased, the response of the rotor system was significantly optimized, and the system tended to stabilize gradually. Therefore, this paper provides a theoretical basis and experimental verification for the optimization of a pelleting machine transmission structure.

Development of a method for determining the rational installation location of technical means of symmetry in an electrical complex with the presence of an electric motor load

The work is devoted to the development of a methodological approach to correcting the level of supply voltage in the electrical network by developing an algorithmized method for determining the rational installation location of technical means of symmetry in an electrical complex with the presence of an electric motor load. The developed method makes it possible to implement processes aimed at ensuring the effective functioning of the electrical complex with the presence of an electric motor load in conditions of low-quality supply voltage. The proposed method, based on software, provides design procedures for calculating various options for symmetry and choosing the most economically feasible. Attention is focused on the main criteria for evaluating decisions made when designing the location of technical means of symmetry in the electrical complex. The architecture, the main functional features of the application program as a tool for implementing the calculation method are considered. The program ensures the implementation of electrical calculations in the design, modernization and operation of electrical networks. It provides for the construction of schematic diagrams of sections of electrical complexes with installed means of symmetry. The results of experimental studies demonstrating the effectiveness of the developed method in solving problems of voltage symmetry in the supply electrical network are presented. It is obvious that the developed approach, based on the automatic selection of the locations of the means of symmetry depending on the operating conditions of the electric motor load, makes it possible to automate the design procedures for voltage normalization in the electrical network. Provides minimization of voltage asymmetry in the supply electrical network, contributes to improving the operational reliability of low-voltage asynchronous electric motors. The obtained research results and prospects for the application of the developed approach are discussed, both for solving complex design problems and for the economic justification of local design solutions. A detailed analysis and formalization of the results of the study with relevant conclusions were carried out.

Experimental Investigation of the Isothermal Section in the Al–Si–Y System at 773 K

The phase equilibrium and phase transformation of the Al–Si–Y ternary system were investigated in 80 annealed alloys using an electron probe microanalysis (EPMA), X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The phase equilibrium at 773 K was determined, and the phase distribution and solid solubility of the Al–Si–Y isothermal section at 773 K were obtained. A total of 23 three-phase zones and 4 two-phase zones were obtained, and 2 new ternary compounds, AlSi4Y5 and Al2Si3Y5, were identified from the non-aluminum-rich corner. Additionally, the phase transition temperatures of representative alloys were determined by the DSC method, and then the phase transition temperatures were processed to obtain the experimental points of vertical sections. In the Al–Si–Y alloy system, the phase diagrams of the vertical sections with X(Al) = 90 at.%, 80 at.%, 70 at.% and 60 at.% at the aluminum-rich corner were calculated, and then the experimental points were inserted into the vertical section phase diagrams. The results of the vertical sectional experiments obtained from the validation experiments are in good agreement with the vertical sectional data obtained from the calculations, indicating that the validated thermodynamic description is useful for the microstructure design of the aluminum-rich corner of the Al–Si–Y ternary alloy.

Application of the high-density resistivity method in detecting a mined-out area of a quarry in Xiangtan City, Hunan Province

Goaf ground collapse has great constraints on people’s lives, property safety, and social development within the influence scope because of its concealment and suddenly happening characteristics. The high-density resistivity method is used to explore the goaf of a quarry in Xiangtan City, Hunan Province. The surface subsidence of the goaf is analyzed using the apparent resistivity inversion section diagram and the comprehensive analysis results. The filling water or sediment in the goaf is reflected as a low-resistivity abnormal body, with a resistivity change that is significantly different from the resistivity change of the surrounding bedrock and the contour fluctuation. The morphological characteristics and geological conditions of the underground abnormal body in the goaf are deduced. Based on the geophysical prospecting method, geological disasters such as goaf ground collapse can be explored. From the combined analysis and processing of inversion data, the geological structure and stratum information of goaf can be inferred, which provides a theoretical basis for further disaster prevention.

The design of a four-wing chaotic system and the application of synchronous control in weak signal detection

Simple fourth-order autonomous differential equations can exhibit chaotic properties. In this paper, a chaotic system with a four-wing attractor is proposed where the varying number of attractor wings depends not only on the system parameters but also on the initial state of the system. First, the phase diagram, Lyapunov exponential (LE) spectrum, bifurcation diagram, Poincaré section diagram and 0–1 test diagram can verify that the system has more complex dynamic characteristics. Meanwhile, not only is the randomness of the system is verified by complexity analysis, but the multistability of the system, namely, the coexistence attractor, is also simulated. Second, using Multisim to build an analog circuit diagram, the circuit simulation results and numerical simulation results coincide, proving the circuit feasibility of the system. Finally, a suitable controller is designed based on Lyapunov stability theory to realize the synchronization of the drive-response system. On the basis of synchronization, disturbance (measured signal) is added to the response system to transform the signal detection into the synchronization error analysis of the drive-response synchronization system. The frequency of synchronization error is obtained by frequency domain analysis, and the frequency value estimated by the multiple signal classification (MUSIC) algorithm. It is found that the proposed chaotic system has more complex dynamics. The method of synchronization control error combined with spectrum estimation can effectively estimate the frequency of weak signal and provide a large detection threshold for weak signal detection.

Rubbing vibration characteristics of double-rotor system under wave load

Structural characteristics of a certain type of gas turbine double rotor and its hull are analyzed. The wave of a regular form is considered, and the wave load is simplified to the form of sinusoidal force. The rubbing force and nonlinear supporting force of the bearing are deduced as per the Hertz contact theory and Coulomb friction law. The mechanical model of the double rotor system under the combined action of the wave load and rotor friction impact is established, which is solved by the fourth-order Runge-Kutta method. The bifurcation diagram, phase diagram, Poincare section diagram, axis trajectory diagrams, effects of rotor eccentricity, and friction coefficient on the nonlinear dynamic characteristics of the system under rub impact fault are studied. The obtained results show that with an increase in eccentricity, the system enters into a chaotic state through the period doubling and paroxysmal bifurcations, and successively experiences nonlinear behaviors such as periodic 2 bifurcation, periodic 4 bifurcation, and quasi periodic and chaos. In the double rotor system, the nonlinear dynamic behavior of the single period and semi Nermark-Sacker bifurcation occurs with increasing friction coefficient. The present findings can provide a theoretical basis for condition monitoring, fault diagnosis, and design optimization of this type of gas turbine double rotor system.

A Novel four - Wing chaotic system with multiple attractors based on hyperbolic sine: Application to image encryption*

A novel symmetrical four-wing fourth-order chaotic system is constructed. The basic dynamic characteristics of the system were analyzed by phase diagram, bifurcation diagram, Lyapunov index spectrum, Poincare cross section diagram and 0–1 test. In addition, the chaotic attractors under different parameters in the system are analyzed. In the dynamic analysis of the new system, it is found that the new system has some characteristics, such as multi-stability, offset boosting, multi-state transition phenomenon, transient chaos and intermittent chaos, and coexistence of multiple attractors. These features have the value of in-depth analysis compared to previous systems and can make it promising for more applications. Moreover, after calculating the complexity of the system by C0 algorithm at different initial values, it is found that the complexity of the system has been stable. Due to the existence of many characteristics, the new chaotic system has attracted great attention. At the same time, the circuit design of the system is realized by using Multisim simulation software and FPGA digital hardware circuit. Finally, a novel and efficient image encryption algorithm is designed by combining multi-direction pixel scrambling and DNA dynamic encryption. The NIST test, key space, encryption histogram, adjacent pixel correlation, robustness and information entropy are analyzed by encrypting images using chaotic sequences of the new system. In a word, its plentiful characteristics and intricate phenomena have significant reference value in the field of chaotic image encryption.

Nonlinear dynamics analysis of multifactor low-speed heavy-load gear system with temperature effect considered

Low-speed and heavy-load gears generate a lot of heat during meshing transmission, which leads to thermal deformation of the gears and affects the transmission performance of the gear system. It is of great significance to explore the influence law of temperature effects on the nonlinear dynamics of the gear system. Based on the principle of thermal deformation, taking into account the temperature effect and nonlinear parameters, including time-varying meshing stiffness, tooth side clearance as well as comprehensive errors, a nonlinear dynamic model of the gear system of spur cylindrical gear system is established. The Runge–Kutta method is used for numerical solution, the effect of temperature variation and time-varying stiffness coefficient on the bifurcation characteristics of the gear system is analyzed by combining bifurcation diagram, maximum Lyapunov index diagram, phase diagram and Poincare section diagram. The results show that the gear system exhibits complex nonlinear dynamics with the consideration of temperature effects, including four states of single-fold periodic motion, multi-fold periodic motion, and bifurcation and chaotic motion. The influence of temperature variation on the nonlinear characteristics of the gear system is closely related to the value of the time-varying stiffness coefficient. The effect of temperature variation on the bifurcation characteristics of the system is obvious when the value of the time-varying stiffness coefficient s is in the range of 0.4 < s < 0.8. The relevant conclusions can provide references for the design of gear systems under special working conditions.