Airplane flap fatigue reliability analysis method, system, equipment and medium

Abstract

The invention provides an aircraft flap fatigue reliability analysis method, system, device and medium, and belongs to the technical field of aerospace ground tests.The method comprises the steps that a parameterized assembly model comprising a flap system, an active driving system and a follow-up loading system is constructed; a Simscape Multibody Link plug-in is used for converting the model, the model is imported into a Simulink platform, and a parameterized multi-body dynamics basic model is generated; on the basis, a control logic module, a PID closed-loop feedback controller and a hydraulic transmission system simulation module based on the specific kinematics geometrical relationship of the flap system are integrated, and a mechanical-electrical-hydraulic deep coupling joint simulation model is formed. The joint simulation model is used for simulating the fatigue test working condition, high-fidelity load time history data are synchronously collected, then fatigue damage analysis and life prediction of the flap structure are completed, and the test efficiency and the evaluation precision are greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of aerospace ground testing technology, specifically relating to an analysis method, system, equipment, and medium for the fatigue reliability of aircraft flaps. Background Technology

[0002] In the aviation field, fatigue reliability testing of key components such as aircraft flaps is an important step in ensuring aircraft safety.

[0003] In existing technologies, fatigue reliability verification mainly relies on physical testing methods. Specifically, it requires manufacturing a full-size flap structure and a complete test bench system. This bench typically includes: an active drive system that provides power, consisting of a planetary geared motor, coupling, and ball screw assembly, used to precisely drive the flap to achieve angular deflection from 0° to 35°; and a servo loading system that tracks the load, consisting of upper and lower servo modules. Each module includes a precision slide driven by a servo motor, a hydraulic actuator, and a steel wire rope or rigid connecting rod connecting the flap loading point to ensure that the loading force always acts perpendicularly on the skin surface during flap rotation.

[0004] While the aforementioned physical testing methods are direct and reliable, they have significant drawbacks: First, the testing cycle is lengthy, taking months or even years from the manufacture of physical prototypes, the construction of test benches, the deployment of sensors, to the completion of long-term loading at the level of millions of cycles. Second, the economic costs are high, involving the loss of high-value specimens, the processing of special non-standard test benches, energy consumption, and the investment in expensive testing equipment and personnel. Third, the testing risks and limitations are prominent, complex loading conditions (such as extreme deflection angles and variable amplitude loads) can easily lead to accidental damage to the specimens, and it is difficult to safely and comprehensively reproduce all boundary conditions and failure modes, which may miss potential fatigue damage mechanisms.

[0005] To address these issues, recent research has introduced simulation techniques, such as using SolidWorks for 3D mechanical modeling or simulating control systems independently in MATLAB / Simulink to aid in design and verification. However, SolidWorks 3D mechanical modeling focuses solely on geometry and assembly relationships, neglecting control logic integration. Simulating control systems independently in MATLAB / Simulink fails to fully integrate the physical properties of the mechanical structure, leading to a disconnect between the dynamic response and control logic adjustments. This results in an inability to fully reproduce the boundary conditions of physical experiments and to cover complex dynamic conditions such as flap rotation (0°-35°) and vertical force application under servo loading. Consequently, existing simulation techniques sometimes overlook key fatigue damage mechanisms, resulting in significant discrepancies between simulation results and actual physical experiments, and failing to provide high-precision support for fatigue reliability assessment. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a method, system, device, and medium for analyzing the fatigue reliability of aircraft flaps.

[0007] To achieve the above objectives, the present invention provides a method for analyzing the fatigue reliability of aircraft flaps, comprising: A parametric assembly model of the target aircraft flap test bench is constructed, the assembly model including: flap system, active drive system and follow-up loading system; the assembly model is converted into a parametric multibody dynamics basic model; based on the multibody dynamics basic model, a control logic module, a closed-loop feedback controller and a hydraulic transmission system simulation module based on the specific kinematic geometry of the flap system are constructed and integrated to form a mechanical-electrical-hydraulic joint simulation model of the target aircraft flap.

[0008] A fatigue test spectrum of the target aircraft flap cyclic motion cycle is preset, and the fatigue test spectrum is converted into a time-domain control command signal to guide the rotation angle and amplitude of the target aircraft flap system. The time-domain control command signal is calculated into target position commands to drive the active drive system and the follow-up loading system through the control logic module. The target position commands include: the target displacement of the lead screw of the active drive system, the cooperative target position of the servo motor in the follow-up loading system, and the target extension and retraction of the hydraulic actuator.

[0009] During the execution of the target position command, time history data of the forces or moments acting on predetermined parts of the flap structure are collected synchronously to form a load-time history; based on the load-time history, the fatigue damage degree of the target aircraft flap structure is analyzed.

[0010] Preferably, the parametric assembly model is constructed in the 3D CAD software SolidWorks; the flap system is used to simulate the flap structure and rotation, adopting a double-beam ribbed box segment structure, divided into a leading edge, a main box segment and a trailing edge area, and is rotated through rocker arms and hinges, with a ball joint shaft at the bottom connected to the follow-up loading system; the active drive system is used to provide the power to drive the flap rotation, outputting power through a planetary geared motor, which converts the power into linear drive through a coupling and lead screw assembly, realizing angle adjustment of the flap within a specific angle range, and the drive process is based on the calculation of the lead screw lead and the number of motor rotations based on the rotation angle.

[0011] Preferably, the assembly model is exported as an XML file and a STEP file using the Simscape Multibody Link plugin, and then imported into MATLAB / Simulink software to generate a parametric multibody dynamics basic model. The multibody dynamics basic model includes constraints related to flap hinges, follower sliding, actuator extension and rotation, and vertical relationships, and integrates rotation angle sensors and displacement sensors.

[0012] Preferably, the modules are integrated in the MATLAB / Simulink environment to form a mechatronics-hydraulic integrated simulation model with virtual sensor feedback and real-time control functions; the control logic module is based on an isosceles triangle geometric model or equivalent kinematic model representing the spatial relationship between the flaps, drive screws and follower mechanisms; the hydraulic transmission system simulation module is built based on the Simscape Fluids library to simulate the dynamic characteristics of the hydraulic oil source, control valves and actuators, and converts the target extension and retraction of the hydraulic actuators into corresponding pressure and flow signals to drive the hydraulic actuators in the model to generate simulated loading forces.

[0013] Preferably, the servo loading system includes an upper servo system and a lower servo system; the control logic module of the upper servo system integrates dedicated components to simulate the elasticity of the wire rope, and introduces an elastic compensation amount during the calculation, which is determined based on the tension, original length, cross-sectional area, and elastic modulus of the wire rope; the control logic module of the lower servo system adopts a rigid connection model, and does not consider elastic deformation during the calculation, but only calculates the target position of the slider and the extension and retraction of the actuator cylinder through geometric relationships; the synchronous acquisition of the time history data of the force or torque specifically includes: obtaining the torque time history at the flap hinge by accessing the joint constraint force port in the multibody dynamics basic model; and obtaining the force time history at the servo loading point through the force sensor module.

[0014] Preferably, the time-domain control command signal is calculated into target position commands to drive the active drive system and the follow-up loading system. Specifically, this includes: using a Simulink-embedded mathematical function module to calculate the flap target angle in real time into the lead screw target displacement, the follow-up slider target position, and the hydraulic actuator target extension / retraction amount; the upper follow-up system tightens or loosens the steel wire rope through the loading cylinder, and simultaneously adjusts the position of the movable pulley through the servo motor to ensure that the steel wire rope remains perpendicular to the loading point; the lower follow-up system adjusts the position of the cylinder slider through the servo motor, and coordinates with the piston rod extension / retraction action to achieve a loading direction perpendicular to the loading point.

[0015] Preferably, before synchronously acquiring the time history data of the force or torque acting on the predetermined part of the flap structure, the method further includes: acquiring the actual motion data of each actuator through virtual sensors in the model during the operation of the co-simulation model; calculating the tracking error between the target position command and the actual motion data through the closed-loop feedback controller, and generating a correction control quantity; feeding the correction control quantity back to the drive input of the model to form a complete simulation control; the closed-loop feedback controller is a PID controller, and the correction control quantity includes a motor torque correction command, a servo motor speed correction command, and a hydraulic valve opening correction signal.

[0016] This invention also provides an analysis system for the fatigue reliability of aircraft flaps, comprising: The model building module is used to construct a parametric assembly model of the target aircraft flap test bench. The assembly model includes a flap system, an active drive system, and a follow-up loading system. The assembly model is converted into a parametric multibody dynamics basic model. Based on the multibody dynamics basic model, a control logic module, a closed-loop feedback controller, and a hydraulic transmission system simulation module based on the specific kinematic geometry of the flap system are constructed and integrated to form a mechanical-electrical-hydraulic joint simulation model of the target aircraft flap.

[0017] The simulation experiment module is used to preset the fatigue test spectrum of the target aircraft flap cyclic execution motion cycle, and convert the fatigue test spectrum into a time-domain control command signal to guide the rotation angle and amplitude of the target aircraft flap system; through the control logic module, the time-domain control command signal is calculated into target position commands to drive the active drive system and the follow-up loading system; the target position commands include: the target displacement of the lead screw of the active drive system, the cooperative target position of the servo motor in the follow-up loading system, and the target extension and retraction of the hydraulic actuator cylinder.

[0018] The fatigue analysis module is used to synchronously collect time history data of the forces or moments acting on predetermined parts of the flap structure during the operation of the target position command, forming a load-time history; and to analyze the fatigue damage degree of the target aircraft flap structure based on the load-time history.

[0019] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement any of the steps in the method for analyzing the fatigue reliability of the aircraft flap.

[0020] The present invention also provides a computer-readable storage medium storing a computer program that, when loaded by a processor, can execute any of the steps in the analysis method for the fatigue reliability of the aircraft flap.

[0021] The method for analyzing the fatigue reliability of aircraft flaps provided by this invention has the following beneficial effects: First, this invention constructs a parameterized assembly model including the flap, active drive, and servo loading system, completely restoring the geometric structure and assembly relationships of each system. Then, it transforms this model into a parameterized multibody dynamics fundamental model, retaining key physical properties such as mass and moment of inertia. Based on this, it further integrates a control logic module, a controller, and a hydraulic transmission system simulation module based on the specific kinematic geometry of the flap. This breaks through the limitations of traditional simulations that separate mechanical modeling and control simulation on a single platform, achieving deep coupling of mechanical, electrical, and hydraulic multi-systems, allowing the mechanical structure to... The dynamic motion of the structure, the real-time adjustment of the control logic, and the power transmission of the hydraulic system are linked to achieve integrated dynamic simulation. Then, by pre-setting the fatigue condition test spectrum and converting it into time-domain control command signals, the simulation conditions are ensured to be consistent with the actual flight fatigue scenario. Furthermore, the control logic module accurately calculates the time-domain commands into specific target commands such as the target displacement of the active drive system screw, the coordinated position of the servo motor of the follow-up system, and the extension and retraction of the hydraulic actuator. At the same time, the force or torque time history data of the predetermined part of the flap are collected to form an accurate load-time history, providing reliable data support for fatigue damage analysis and greatly improving the accuracy of simulation prediction. Attached Figure Description

[0022] To more clearly illustrate the embodiments and design schemes of the present invention, the accompanying drawings required for this embodiment will be briefly described below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart illustrating an analysis method for the fatigue reliability of aircraft flaps according to an embodiment of the present invention. Figure 2 This is the overall structure of the flap motion system according to an embodiment of the present invention; Figure 3 This is the test specimen support structure according to an embodiment of the present invention; Figure 4 This is the active drive system structure according to an embodiment of the present invention; Figure 5 This is the upper follower system structure according to an embodiment of the present invention; Figure 6 This is the lower servo system structure according to an embodiment of the present invention; Figure 7 This is a flowchart illustrating the import process from SolidWorks to MATLAB / Simulink according to an embodiment of the present invention. Figure 8 This is a simulation model diagram of an embodiment of the present invention; Figure 9This is an active motion relationship diagram according to an embodiment of the present invention; wherein, Figure 9 (a) is the active motion control diagram. Figure 9 (b) represents the parameter corresponding to flap rotation. Figure 9 (c) represents the functional relationship between the flap rotation angle and the linear displacement of the slider; Figure 10 The steel wire rope of the upper follower system in this embodiment of the invention; Figure 11 This is a motion analysis diagram of the upper follow-up loading system according to an embodiment of the present invention; Figure 12 This is a motion analysis diagram of the lower follower loading system according to an embodiment of the present invention; Figure 13 In this embodiment of the invention, the flap rotation angle is 0°; Figure 14 In this embodiment of the invention, the flap rotation angle is 17°; Figure 15 In this embodiment of the invention, the flap rotation angle is 23°; Figure 16 In this embodiment of the invention, the flap rotation angle is 35°. Detailed Implementation

[0024] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0025] This invention provides a method for analyzing the fatigue reliability of aircraft flaps, and a control simulation system applicable to aircraft flap fatigue reliability testing. This method couples mechanical modeling, control logic, and dynamic simulation, significantly shortening the verification cycle and improving prediction accuracy. Specifically, as follows... Figure 1 As shown, it includes:

[0026] S1. Construct a parametric assembly model of the target aircraft flap test bench. The assembly model includes a flap system, an active drive system, and a follow-up loading system. Convert the assembly model into a parametric multibody dynamics basic model. Based on the multibody dynamics basic model, construct and integrate a control logic module, a closed-loop feedback controller, and a hydraulic transmission system simulation module based on the specific kinematic geometry of the flap system to form a mechanical-electrical-hydraulic joint simulation model of the target aircraft flap.

[0027] This invention constructs a 3D parametric assembly model of a flap system, an active drive system, and a follow-up loading system (upper and lower follow-up loading systems) using SolidWorks. This model integrates the subsystems to achieve rotational logic and loading adaptation. XML and STEP files are exported using the Simscape Multibody Link plugin and imported into MATLAB / Simulink to generate a multibody dynamics model. Constraints (such as Revolute Joints and Prismatic Joints), sensors (such as rotation angle sensors), and input signals (such as angle signals from 0° to 35°) are added in Simulink. Active motion control establishes a rotation angle and displacement model based on geometric relationships and uses a PID closed-loop to calculate the number of rotations. For follow-up motion control, the upper follow-up uses a Belt-Cable component to simulate the elasticity of a wire rope, calculating pulley displacement and extension (considering elastic deformation; the elastic compensation is determined based on parameters related to the wire rope's tension, original length, cross-sectional area, and elastic modulus). The lower follow-up uses a rigid connection to calculate slider displacement and extension, integrating a Fluid module to simulate an electro-hydraulic oil source. The simulation process runs the model, applies signals, outputs curves, and visualizes them using MechanicsExplorer, supporting optimization.

[0028] The parametric assembly model of the target aircraft flap test bench includes: a flap system, an active drive system, and a servo loading system. Their connections are simulated according to the flap system of a real aircraft. The flap system is used to simulate the flap structure and rotation. It adopts a double-beam ribbed box-section structure, divided into leading edge, main box section, and trailing edge areas. Rotational connections are achieved through rocker arms and hinges. A ball joint shaft is configured at the bottom to connect with the servo loading system. The active drive system provides the power to drive the flap rotation. Power is output through a planetary geared motor, and the power is converted into linear drive through a coupling and lead screw assembly to achieve angle adjustment within a specific angle range of the flap. The drive process is based on the calculation of the lead screw lead and the number of motor rotations based on the rotation angle.

[0029] Figures 2 to 14 This is the entire aircraft flap fatigue reliability test control simulation subsystem based on Multibody and Simulink. The flap system, for example... Figure 1 and Figure 2As shown, a 3D model was constructed using SolidWorks software, including the flap body, left and right rocker arms, support arm joint assembly, lead screw and nut, hinge support, hinge pillar, and support box section, ensuring the accuracy of the geometric structure, assembly constraints, and spatial layout between components. The flap body adopts a double-beam, closely ribbed box section structure, divided into the front edge (skin, end ribs, ordinary ribs), the main box section (beam, wall panel, end ribs, ordinary ribs, reinforcing ribs), and the rear edge (wall panel, end ribs, ordinary ribs, reinforcing ribs) area. It is fixed by bolts on the upper part of the left and right rocker arms and connected by hinges at the bottom. Lead screws and nuts and ball joints are configured to achieve angle adjustment and follow-up connection.

[0030] Active drive systems such as Figure 4 As shown, the system integrates a planetary geared motor, transmission box, coupling, lead screw assembly, drive support, and motor support. The motor is fixed to the support box section, and its output end is coaxially connected to the coupling, diverting power to the lead screw assembly to achieve flap rotation. The drive process first calculates the lead screw lead and linear displacement based on the desired rotation angle, and then calculates the number of motor rotations by combining the pitch, diameter, and reduction ratio.

[0031] Follow-up loading systems are divided into upper follow-up loading systems and lower follow-up loading systems, such as... Figure 5 and Figure 6 As shown. The upper follow-up loading system comprises three subsystems, each including a loading cylinder, a roller piston rod, an upper module assembly (servo motor, lead screw assembly, movable pulley), a fixed pulley, and a steel wire rope. The upper module assembly and the fixed pulley are fixed to the top of the frame, the cylinder is hinged to the bottom, one end of the steel wire rope is fixed to the loading point, and the other end is connected to the piston rod. When the flap rotates, the cylinder tightens / unwinds the steel wire rope, and the servo motor adjusts the position of the movable pulley to ensure verticality. The lower follow-up loading system comprises three subsystems, each including a cylinder barrel, a piston rod, and a lower module assembly (servo motor, lead screw assembly, module base, cylinder slider). The lower module assembly is fixed to the bottom of the frame, and the cylinder barrel is hinged to the slider. During rotation, the servo motor adjusts the slider position, and the piston rod extends and retracts to ensure verticality.

[0032] Model import process as follows Figure 7As shown, the Simscape Multibody Link plugin was used to export the SolidWorks model as XML (describing constraints and physical properties) and STEP (geometry file) files, which were then imported into MATLAB / Simulink to generate a multibody dynamics model. This transformed the assembly model into a parametric multibody dynamics foundational model. Based on the multibody dynamics foundational model, a control logic module for specific kinematic geometric relationships of the flap system, a closed-loop feedback controller, and a hydraulic transmission system simulation module were constructed and integrated to form a combined electromechanical-hydraulic simulation model of the target aircraft flaps. The multibody dynamics model retains the original aircraft's mass, moment of inertia, and other properties. Constraints related to flap hinges, follow-up sliding, actuator extension and rotation, and vertical relationships were added to the multibody dynamics foundational model, and rotation angle sensors and displacement sensors were integrated.

[0033] To further enhance the imported Simulink interface, constraints, sensors, and input signals are added: Constraints include RevoluteJoint (flap hinge, range 0°-35°), Prismatic Joint (follower sliding), Cylindrical Joint (actuator telescoping and rotation), and Planar Joint (vertical relationship); Sensors include rotation angle sensors (monitoring rotation angle) and displacement sensors (monitoring sliding), outputting to the feedback loop; Input signals include angle signals (sine, nodes 0°, 17°, 23°, 35°), displacement signals (maximum 0.4m), and telescoping signals. The simulation model diagram is shown below. Figure 8 As shown.

[0034] S2. A fatigue test spectrum of the target aircraft flap cyclic execution motion cycle is preset, and the fatigue test spectrum is converted into a time-domain control command signal to guide the rotation angle and amplitude of the target aircraft flap system; through the control logic module, the time-domain control command signal is calculated into a target position command to drive the active drive system and the follow-up loading system; the target position command includes: the target displacement of the active drive system screw, the cooperative target position of the servo motor in the follow-up loading system, and the target extension and retraction of the hydraulic actuator cylinder.

[0035] Active motion control such as Figure 9 As shown in (a), the control logic module is based on an isosceles triangle geometric model or equivalent kinematic model representing the spatial relationship between the flaps, drive screw, and servo mechanism. The set fatigue test spectrum is transformed according to the following steps: Assume the aircraft flap system rotation angle is... The corresponding vertex angle is the vertex angle of the isosceles triangle, such as... Figure 9 As shown in (b), the length of the isosceles triangle leg corresponding to the flap rotation is denoted as . The length of the leg of the isosceles triangle corresponding to the rotation of the leadscrew is denoted as . These two geometric parameters can be directly measured from the SolidWorks 3D model. As shown in Figure 9(c), based on the geometric relationship of isosceles triangles, the functional relationship between the flap rotation angle and the linear displacement of the slider can be obtained: ,in, , , , , , , , These parameters have no practical meaning; they are merely auxiliary parameters set for ease of calculation. This function, acting as an input signal (the time-domain control command signal for amplitude), drives the RevoluteJoint in the Multibody model, ensuring synchronization with the servo loading system.

[0036] In servo motion control, the servo is coordinated with the flaps via a steel wire rope, such as... Figure 10 As shown, components such as Pullley and Belt-Cable in Simulink are used to simulate a steel wire rope. The geometric relationship of the follower motion is as follows: Figure 11 As shown, the time-domain control command signal is decoded into target position commands to drive the active drive system and the servo loading system. The upper servo system tightens or loosens the wire rope through the loading cylinder, while simultaneously adjusting the position of the movable pulley through the servo motor to ensure that the wire rope remains perpendicular to the loading point. The lower servo system adjusts the position of the cylinder slider through the servo motor, coordinating with the piston rod's extension and retraction to achieve a loading direction perpendicular to the loading point. Assume the initial vertical distance between the pulley and the flap loading point is... When the flap rotation angle is When the pulley moves to the new position, the distance it travels is recorded as . At this time, the vertical distance between the pulley and the flap is set to , The distance in the horizontal direction from the initial loading point of the flap to the end of the flap rocker arm. The distance in the vertical direction from the end of the flap rocker arm to the initial loading point of the flap. This refers to the distance from the point where the wire rope is fixed to the flap loading point to the initial loading point after the flap rotates. This represents the vertical distance from the point where the wire rope is fixed to the flap loading point to the horizontal plane where the initial loading point is located after the flap rotates (the subscript of x has no practical meaning; it is merely an auxiliary variable set for ease of calculation). Additionally, in the figure... and It can also be measured; the slider displacement can be obtained based on geometric relationships. Displacement of the actuator cylinder , Elastic compensation was added. The output was integrated into the Prismatic Joint, and PID control was used to minimize the error. The simulation results were verified by observing the rope deformation and force curves through the Mechanics Explorer.

[0037] The lower servo motor coordinates its movement with the servo module via three hydraulic actuators, and their geometric relationship is as follows: Figure 12 As shown, a rigid connection is used: the initial vertical distance between the loading point below the flap and the lower screw module of the active drive system is... , For flap rotation After the angle is adjusted, the distance between the loading point below the flap and the lower lead screw module is... This is the horizontal distance between the fixed point of the flap rocker arm on the flap and the loading point below the flap. This is the distance in the vertical direction from the end of the flap rocker arm to the initial loading point of the flap. Geometric calculations show that when the flap rotates... At the angle, the target displacement sliding amount of the hydraulic actuator on the lower lead screw module is The extension / retraction range of the hydraulic actuator is And the coordinated target position of the servo motor in the follow-up loading system is d Then, similarly, the output can be integrated into the Prismatic Joint, adjusted using PID control (closed-loop feedback controller) to minimize the error, and the simulation results can be verified by observing the rope deformation and force curves through the Mechanics Explorer.

[0038] S3. During the execution of the target position command, the time history data of the force or torque acting on the predetermined part of the flap structure are collected synchronously to form a load-time history; based on the load-time history, the fatigue damage degree of the target aircraft flap structure is analyzed.

[0039] During the operation of the co-simulation model, the actual motion data of each actuator is acquired through virtual sensors in the model; the tracking error between the target position command and the actual motion data is calculated through the feedback controller, and a correction control quantity is generated; and it is fed back to the drive input of the model to form a complete simulation control; the correction control quantity includes motor torque correction command, servo motor speed correction command and hydraulic valve opening correction signal.

[0040] The simulation process runs the entire Simulink model, applying step or sinusoidal signals. The control logic module accesses the joint constraint force ports in the multibody dynamics fundamental model to obtain the torque time history at the flap hinge. The force sensor module acquires the force time history at the servo loading point, outputting the time history data of the force or torque, which can also be displacement, velocity, and force curves, forming a load-time history. This is then visualized and animated using Mechanics Explorer (30 FPS). Figure 13-16 As shown. Verification at different angles: initial position at 0°; upper follower displacement 0.37m, actuator cylinder 0.40m, lower follower 0.31m, 0.06m at 17°; 0.51m, 0.55m, 0.43m, 0.11m at 23°; 0.83m, 0.90m, 0.70m, 0.26m at 35°, ensuring vertical force application, and analyzing the fatigue damage degree of the target aircraft flap structure.

[0041] This invention utilizes a seamless integration platform of SolidWorks and MATLAB / Simulink to achieve full-process virtual simulation of aircraft flap fatigue reliability testing. First, three-dimensional models of the flap system, active drive system, upper follow-up loading system, and lower follow-up loading system are constructed in SolidWorks, including geometric structures, assembly constraints, and physical properties (such as mass and moment of inertia). Second, XML files (physical properties) and STEP files (geometry) are exported using the Simscape Multibody Link plugin and imported into Simulink to generate a multibody dynamics model. Then, motion constraints (such as Revolute Joint simulating flap rotation), sensors (such as displacement sensors), and input signals (such as sine waves driving 0°~35° rotation angles) are added in the Simulink environment. Integrated PID closed-loop control and the Simscape Fluids module simulate the electro-hydraulic system, used to control the dynamic characteristics of the valves and actuators, and converting the target extension and retraction of the hydraulic actuators into corresponding pressure and flow signals to drive the hydraulic actuators in the model to generate simulated loading forces. Finally, run the simulation and output the time history data of the applied force or torque, or displacement, velocity, and force curves to form a load-time history. Then, use Mechanics Explorer to create a 3D visualization animation, supporting parameter optimization and fatigue analysis.

[0042] This invention achieves the coupling of mechanical structure, control logic, and hydraulics. The flap system of this invention adopts a double-beam, closely ribbed box-section structure, divided into a leading edge, a main box section, and a trailing edge region. It is fixed by upper bolts on the left and right rocker arms, connected by bottom hinges, and angle adjustment and follow-up connection are achieved through a lead screw nut and a ball joint shaft. The active drive system includes a planetary geared motor, a transmission box, a coupling, a lead screw assembly, a drive support, and a motor support. The motor is fixed to the support box section, and its output power is split through the coupling to the lead screw, which meshes with the lead screw nut to drive the flap rotation. The core algorithm is based on an isosceles triangle geometric model, such as... Figure 9 As shown: (1) Let the waist length of the flap be (2) is the turning angle. (3) represents the length of the lead screw waist. Then the bottom edge displacement The model is implemented in a MATLAB Function block, used as input to a RevoluteJoint to ensure accurate corner conversion.

[0043] The upper-follower loading system of this invention comprises three subsystems, each consisting of a loading cylinder (1000mm stroke), a roller piston rod, an upper module assembly (servo motor, lead screw, movable pulley), a fixed pulley, and a steel wire rope. The upper module is fixed to the top of the frame, the cylinder hinge is fixed to the bottom, and the steel wire rope connects the loading point and the piston rod. The elasticity of the steel wire rope is simulated using Pullley and Belt-Cable components in Simulink. Figure 11 As shown, its geometric relationship is: initial vertical distance h 0, slider displacement ( and (Measurable), new vertical distance The actuator cylinder extends and retracts. The elastic compensation Δ_e = F L0 / (A×E) (F is the tensile force, L0 is the original length, A is the cross-sectional area, and E is the modulus). The output is integrated into the Prismatic Joint to ensure vertical loading.

[0044] The lower servo loading system of this invention comprises three subsystems, each consisting of a hydraulic cylinder (500mm stroke), a piston rod, and a lower module assembly (servo motor, lead screw, module base, and hydraulic cylinder slider). The lower module is fixed to the bottom of the frame, and the hydraulic cylinder is hinged to the slider. A rigid connection model is used in Simulink. Figure 12 As shown, its geometric relationship is: initial vertical distance k 0, slider displacement extension and retraction of hydraulic actuator cylinder The output is integrated into the Prismatic Joint, ensuring that the loading point is perpendicular to the flap and there is no cable elasticity deviation.

[0045] This invention realizes virtual simulation of flap fatigue testing. By deeply coupling mechanics and control through a joint platform, it improves evaluation accuracy and ensures test safety. It also significantly improves simulation efficiency and reduces preparation time for fatigue reliability testing. Furthermore, it is highly versatile and can be extended to other aircraft components, saving resources and reducing costs.

[0046] Based on the same inventive concept, this invention also provides an analysis system for the fatigue reliability of aircraft flaps, comprising: The model building module is used to construct a parametric assembly model of the target aircraft flap test bench. The assembly model includes a flap system, an active drive system, and a follow-up loading system. The assembly model is converted into a parametric multibody dynamics basic model. Based on the multibody dynamics basic model, a control logic module, a closed-loop feedback controller, and a hydraulic transmission system simulation module based on the specific kinematic geometry of the flap system are constructed and integrated to form a mechanical-electrical-hydraulic joint simulation model of the target aircraft flap.

[0047] The simulation experiment module is used to preset the fatigue test spectrum of the target aircraft flap cyclic execution motion cycle, and convert the fatigue test spectrum into a time-domain control command signal to guide the rotation angle and amplitude of the target aircraft flap system; through the control logic module, the time-domain control command signal is calculated into target position commands to drive the active drive system and the follow-up loading system; the target position commands include: the target displacement of the lead screw of the active drive system, the cooperative target position of the servo motor in the follow-up loading system, and the target extension and retraction of the hydraulic actuator cylinder.

[0048] The fatigue analysis module is used to synchronously collect time history data of the forces or moments acting on predetermined parts of the flap structure during the operation of the target position command, forming a load-time history; and to analyze the fatigue damage degree of the target aircraft flap structure based on the load-time history.

[0049] This invention also provides a computer device, which, at the hardware level, includes a processor, an internal bus, a network interface, memory, and non-volatile memory, and may also include other hardware required for business operations. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to implement the aforementioned method for analyzing the fatigue reliability of aircraft flaps.

[0050] The present invention also provides a computer-readable storage medium storing a computer program that can be used to execute the above-described method for analyzing the fatigue reliability of aircraft flaps.

[0051] Specific limitations of the calculation system for the analysis method of aircraft flap fatigue reliability can be found in the limitations of the analysis method for aircraft flap fatigue reliability mentioned above, and will not be repeated here. Each module in the above-mentioned aircraft flap fatigue reliability analysis system can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the computer device in hardware form or independent of it, or they can be stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0052] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. Furthermore, the above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for analyzing the fatigue reliability of aircraft flaps, characterized in that, include: A parametric assembly model of the target aircraft flap test bench is constructed, the assembly model including: flap system, active drive system and follow-up loading system; the assembly model is converted into a parametric multibody dynamics basic model; based on the multibody dynamics basic model, a control logic module, a closed-loop feedback controller and a hydraulic transmission system simulation module based on the specific kinematic geometry of the flap system are constructed and integrated to form a mechanical-electrical-hydraulic joint simulation model of the target aircraft flap; A fatigue test spectrum of the target aircraft flap cyclic execution motion cycle is preset, and the fatigue test spectrum is converted into a time-domain control command signal to guide the rotation angle and amplitude of the target aircraft flap system. The control logic module converts the time-domain control command signal into a target position command that drives the active drive system and the follow-up loading system. The target position command includes: the target displacement of the lead screw in the active drive system, the coordinated target position of the servo motor in the follow-up loading system, and the target extension and retraction of the hydraulic cylinder. During the execution of the target position command, time history data of the forces or moments acting on predetermined parts of the flap structure are collected synchronously to form a load-time history; based on the load-time history, the fatigue damage degree of the target aircraft flap structure is analyzed.

2. The method for analyzing the fatigue reliability of aircraft flaps according to claim 1, characterized in that, The parametric assembly model is constructed in the 3D CAD software SolidWorks. The flap system is used to simulate the flap structure and rotation. It adopts a double-beam ribbed box segment structure, which is divided into a leading edge, a main box segment, and a trailing edge area. Rotational connection is achieved through rocker arms and hinges. A ball joint shaft is configured at the bottom to connect with the follow-up loading system. The active drive system is used to provide the power to drive the flap rotation. The power is output through a planetary geared motor, and the power is converted into linear drive through a coupling and lead screw assembly to achieve angle adjustment of the flap within a specific angle range. The drive process is based on the calculation of the lead screw lead and the number of motor rotations based on the rotation angle.

3. The method for analyzing the fatigue reliability of aircraft flaps according to claim 1, characterized in that, Using the Simscape Multibody Link plugin, the assembly model is exported as an XML file and a STEP file. The XML file and STEP file are then imported into MATLAB / Simulink software to generate a parametric multibody dynamics basic model. The multibody dynamics basic model includes constraints related to flap hinges, follower sliding, actuator extension and rotation, and vertical relationships, and integrates rotation angle sensors and displacement sensors.

4. The method for analyzing the fatigue reliability of aircraft flaps according to claim 1, characterized in that, The modules were integrated in the MATLAB / Simulink environment to form a mechatronics joint simulation model with virtual sensor feedback and real-time control functions. The control logic module is based on an isosceles triangle geometric model or equivalent kinematic model representing the spatial relationship between the flaps, drive screws and follower mechanisms. The hydraulic transmission system simulation module is built based on the SimscapeFluids library to simulate the dynamic characteristics of the hydraulic oil source, control valves and actuators, and converts the target extension and retraction of the hydraulic actuators into corresponding pressure and flow signals to drive the hydraulic actuators in the model to generate simulated loading forces.

5. The method for analyzing the fatigue reliability of aircraft flaps according to claim 1, characterized in that, The servo loading system includes an upper servo system and a lower servo system. The control logic module of the upper servo system integrates dedicated components to simulate the elasticity of the wire rope. During the calculation, an elastic compensation amount is introduced, which is determined based on the tension, original length, cross-sectional area, and elastic modulus of the wire rope. The control logic module of the lower servo system adopts a rigid connection model. During the calculation, elastic deformation is not considered, and the target position of the slider and the extension and retraction of the actuator cylinder are calculated only through geometric relationships. The synchronous acquisition of time history data of forces or moments specifically includes: obtaining the time history of the moment at the flap hinge by accessing the joint constraint force port in the multibody dynamics basic model; The force time history at the follow-up loading point is obtained through the force sensor module.

6. The method for analyzing the fatigue reliability of an aircraft flap according to claim 5, characterized in that, The time-domain control command signal is calculated into target position commands to drive the active drive system and the follow-up loading system. Specifically, this includes: using a Simulink-embedded mathematical function module, the flap target angle is calculated in real time into the lead screw target displacement, the follow-up slider target position, and the hydraulic actuator target extension / retraction amount; the upper follow-up system tightens or loosens the steel cable through the loading cylinder, and simultaneously adjusts the position of the movable pulley through the servo motor to ensure that the steel cable remains perpendicular to the loading point; the lower follow-up system adjusts the position of the cylinder slider through the servo motor, and coordinates with the piston rod extension / retraction action to achieve a loading direction perpendicular to the loading point.

7. The method for analyzing the fatigue reliability of aircraft flaps according to claim 1, characterized in that, Before synchronously acquiring the time history data of the force or torque acting on the predetermined part of the flap structure, the method further includes: acquiring the actual motion data of each actuator through virtual sensors in the model during the operation of the co-simulation model; calculating the tracking error between the target position command and the actual motion data through the closed-loop feedback controller, and generating a correction control quantity; feeding the correction control quantity back to the drive input of the model to form a complete simulation control; the closed-loop feedback controller is a PID controller, and the correction control quantity includes a motor torque correction command, a servo motor speed correction command, and a hydraulic valve opening correction signal.

8. A fatigue reliability analysis system for aircraft flaps, characterized in that, include: The model building module is used to build a parametric assembly model of the target aircraft flap test bench. The assembly model includes a flap system, an active drive system, and a follow-up loading system. The assembly model is converted into a parametric multibody dynamics basic model. Based on the multibody dynamics basic model, a control logic module, a closed-loop feedback controller, and a hydraulic transmission system simulation module based on the specific kinematic geometry of the flap system are built and integrated to form a mechanical-electrical-hydraulic joint simulation model of the target aircraft flap. The simulation experiment module is used to preset the fatigue test spectrum of the target aircraft flap cyclic execution motion cycle, and convert the fatigue test spectrum into a time-domain control command signal to guide the rotation angle and amplitude of the target aircraft flap system. The control logic module converts the time-domain control command signal into a target position command that drives the active drive system and the follow-up loading system. The target position command includes: the target displacement of the lead screw in the active drive system, the coordinated target position of the servo motor in the follow-up loading system, and the target extension and retraction of the hydraulic cylinder. The fatigue analysis module is used to synchronously collect time history data of the forces or moments acting on predetermined parts of the flap structure during the operation of the target position command, forming a load-time history; and to analyze the fatigue damage degree of the target aircraft flap structure based on the load-time history.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is loaded by the processor, it is able to perform the steps of the method according to any one of claims 1 to 7.

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