Topological optimization method, device and equipment for complex load working condition of aircraft landing gear and medium

Abstract

The embodiment of the invention discloses a topological optimization method, device, equipment and medium for complex load working conditions of an aircraft landing gear, and belongs to the technical field of structural topological optimizing.The method comprises the steps that an outer cylinder and a rotating sleeve are regarded as a whole, and according to different strokes of a piston rod, the outer cylinder and the rotating sleeve are combined into a whole through the static balance principle; loads borne by a resistance supporting rod, a piston rod, a wheel shaft and a torque arm are translated to corresponding points of an outer cylinder, and the load condition after a force system is simplified is obtained; the method comprises the following steps: constructing an outer cylinder model, expanding a design domain of the outer cylinder model, dividing the design domain and a non-design domain, carrying out grid division to obtain a plurality of grid regions, and adding load and boundary conditions to the design domain in the grid regions according to the load condition after force system simplification, and after optimization setting is carried out by taking the minimum flexibility as an optimization target, a topological optimization result is obtained based on finite element analysis. The overall performance requirement of a complex mechanism system can be met.

Description

Technical Field

[0001] The present application relates to a topology optimization method, device, equipment and medium for complex load conditions of aircraft landing gear, belonging to the technical field of structural topology optimization. Background Art

[0002] The landing gear mechanism is subject to complex load conditions during landing, particularly high impact loads at touchdown. Its key components, including the outer cylinder, piston rod, rotating sleeve, upper and lower torque arms, drag struts, axles, and tires, must all possess extremely high strength and durability to ensure structural safety and reliability. Traditional topology optimization methods typically focus on optimizing individual components and struggle to meet the overall performance requirements of complex mechanical systems. Summary of the Invention

[0003] In order to solve the above technical problems, the present application provides a topology optimization method, device, equipment and medium for complex load conditions of aircraft landing gear to meet the overall performance requirements of complex mechanism systems.

[0004] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by practice of the present application.

[0005] According to one aspect of the present application, a topology optimization method for complex load conditions of an aircraft landing gear is provided. The aircraft landing gear includes an outer tube, a rotating sleeve, a resistance strut, a torque arm, a piston rod, and a tire. The torque arm includes an upper torque arm and a lower torque arm. The rotating sleeve is arranged on the outside of the outer tube. The resistance strut is arranged on the outside of the outer tube. The rotating sleeve is connected to the piston rod via the upper torque arm and the lower torque arm. The piston rod is movably arranged in the outer tube. One end of the piston rod is arranged on the wheel axle of the tire. The method includes: Considering the outer cylinder and the rotating sleeve as one, and based on the different strokes of the piston rod and the principle of static equilibrium, the loads on the resistance support rod, piston rod, axle, and torque arm are translated to the corresponding points on the outer cylinder to obtain the load situation after the simplified force system. An outer cylinder model is constructed based on the aircraft landing gear, and a design domain of the outer cylinder model is expanded while retaining necessary structural parameters of the structure; According to the outer cylinder model after the design domain is expanded, the design domain and the non-designable domain are divided; Meshing the outer cylinder model divided into a design domain and a non-design domain to obtain a plurality of mesh regions, adding loads and boundary conditions to the design domain in the mesh regions according to the load condition after the force system is simplified, and performing optimization settings with minimum flexibility as the optimization goal; After the optimization settings are completed, finite element analysis is performed to obtain the topology optimization results; When performing finite element analysis, boundary conditions are semi-automatically added based on TCL language.

[0006] Furthermore, the outer cylinder and the rotating sleeve are considered as one body. According to the different strokes of the piston rod, the loads on the resistance support rod, piston rod, axle, and torque arm are translated to the corresponding points on the outer cylinder by the principle of static balance. The load situation after the simplified force system is obtained, including: According to the principle of static equilibrium and the principle of force translation, seven equations are obtained by calculating the principal vector equilibrium and principal moment equilibrium, namely the first equation, the second equation, the third equation, the fourth equation, the fifth equation, the sixth equation, and the seventh equation; among them: Taking the piston rod analysis, we get the first equation, the second equation and the third equation, which are expressed as: ; Where, P 1 represents the load at the contact point between the piston rod and the upper part of the outer cylinder. P 2 represents the load at the contact point between the piston rod and the lower part of the outer tube. F kx Indicates the X-direction load at the axle loading point, F 1x Indicates the X-direction load at the hinge point between the wheel axle and the lower torque arm, F O Indicates the end load of the piston rod top, F ky Indicates the Y-axis load at the axle loading point, F 1y Indicates the Y-direction load at the hinge point between the wheel axle and the lower torque arm, Y p1k Indicates the distance between the contact point between the piston rod and the upper part of the outer cylinder and the axle loading point in the Y direction. Y p2k Indicates the distance between the contact point between the piston rod and the lower part of the outer cylinder and the axle loading point in the Y direction. X ok Indicates the distance between the top end face of the piston rod and the axle loading point in the X direction, Y 1k Indicates the distance between the hinge point of the wheel axle and the lower torque arm and the wheel axle loading point in the Y direction, X 1k Indicates the distance between the hinge point of the wheel axle and the lower torque arm and the wheel axle loading point in the X direction; Overall analysis yields the fourth, fifth, and sixth equations, which are expressed as: ; Where, F 3x Indicates the X-direction load on the hinge point between the upper torque arm and the optional sleeve. F3y Indicates the Y-axis load on the hinge point between the upper torque arm and the optional sleeve. Y 3k Indicates the distance between the upper torque arm and the optional sleeve hinge point and the axle loading point in the Y direction. X 3k Indicates the distance between the hinge point of the upper torque arm and the optional sleeve and the axle loading point in the X direction; The seventh equation is expressed as: ; Where, Y 23 Indicates the distance in the Y direction between the hinge point of the upper torque arm and the lower torque arm and the hinge point of the upper torque arm and the optional sleeve. X 23 Indicates the distance in the X direction between the hinge point of the upper torque arm and the lower torque arm and the hinge point of the upper torque arm and the optional sleeve; Based on the seven equations, the load condition of the simplified force system is obtained.

[0007] Furthermore, the optimization setting is performed with the minimum flexibility as the optimization goal, including: Set the cell density of the cells in the design domain as a variable; Set constraints, and the upper limit of the constraint volume fraction is 0.3; Taking the minimum flexibility as the optimization goal, the optimization formula is constructed; Based on the optimization formula and the set constraints, optimization parameters are set for optimization to obtain the optimal cell density of cells in the design domain; wherein the optimization parameters include the optimized minimum size and penalty factor.

[0008] Furthermore, the optimization formula is expressed as: ; In the formula, min means minimization, Indicates softness, U T represents the transposed matrix of the overall displacement matrix, U represents the overall displacement matrix, K represents the stiffness matrix, Indicates the unit number, N Indicates the number of units, represents the design variable, P represents the penalty factor, represents the transposed matrix of the unit displacement matrix, represents the unit displacement matrix, represents the element stiffness matrix, Represents the optimized volume, represents the design domain volume, f represents the volume fraction,F represents the load vector, x min Indicates the minimum relative density of the unit.

[0009] Furthermore, the optimized minimum size is 6 times the unit size.

[0010] Furthermore, after the optimization setup is completed, finite element analysis is performed to obtain topology optimization results, including: Based on the finite element model, the loads and analysis steps of various working conditions are set, and the model is topologically optimized using the finite element solver to obtain the topology optimization results.

[0011] Furthermore, when performing finite element analysis, boundary conditions are semi-automatically added based on the TCL language, including: Perform tetrahedral meshing on the imported outer cylinder model; Create different materials and properties, and assign the properties to the corresponding tetrahedral meshes; Create different complexes, load collectors, and load steps; Creating a rigid connection element corresponding to the buffer stroke in the corresponding complex; Create loads for the corresponding load cases on the corresponding rigid link elements.

[0012] According to one aspect of the present application, a topology optimization device for complex load conditions of an aircraft landing gear is further provided. The aircraft landing gear includes an outer tube, a rotating sleeve, a resistance strut, a torque arm, a piston rod, and a tire. The torque arm includes an upper torque arm and a lower torque arm. The rotating sleeve is arranged on the outside of the outer tube. The resistance strut is arranged on the outside of the outer tube. The rotating sleeve is connected to the piston rod through the upper torque arm and the lower torque arm. The piston rod is movably arranged in the outer tube. One end of the piston rod is arranged on the wheel axle of the tire. The device includes: The force system simplification module is configured to treat the outer cylinder and the rotating sleeve as a whole. Based on the different strokes of the piston rod and the principle of static balance, the loads on the resistance support rod, piston rod, wheel axle, and torque arm are translated to the corresponding points on the outer cylinder to obtain the load situation after the force system is simplified. a topology optimization module configured to construct an outer cylinder model based on the aircraft landing gear, expand the design domain of the outer cylinder model while retaining necessary structural parameters of the structure; divide the outer cylinder model after the expanded design domain into a design domain and a non-design domain; mesh the outer cylinder model divided into the design domain and the non-design domain to obtain a plurality of mesh regions, add loads and boundary conditions to the design domain in the mesh regions according to the load conditions after the simplified force system, and perform optimization settings with minimum flexibility as an optimization goal; and after the optimization settings are completed, perform finite element analysis to obtain a topology optimization result; The boundary adding module is configured to implement semi-automatic addition of boundary conditions based on TCL language when performing finite element analysis.

[0013] According to one aspect of the present application, an electronic device is also provided, including: a controller; a memory for storing one or more programs, which, when executed by the controller, enables the controller to implement the above-mentioned topology optimization method for complex load conditions of aircraft landing gear.

[0014] According to one aspect of the present application, a computer-readable storage medium is also provided, on which computer-readable instructions are stored. When the computer-readable instructions are executed by a processor of a computer, the computer executes the above-mentioned topology optimization method for complex load conditions of aircraft landing gear.

[0015] The technical solution provided in this application has at least the following advantages: This application addresses the complex landing gear mechanism by deriving the load transfer path through theoretical mechanics methods and applying this to the outer cylinder, a key component, to achieve more rational load distribution and topological optimization within the overall system. Furthermore, during the optimization process, a custom-written TCL script was introduced to more efficiently and quickly apply boundary conditions, effectively improving computational efficiency and simplifying the operational process. This optimization method not only enhances the overall design accuracy but also significantly enhances the load-bearing performance and lightweight structure of the landing gear.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are incorporated into and constitute a part of the specification, illustrating embodiments consistent with the present application and, together with the specification, serving to explain the principles of the present application. It is obvious that the drawings described below are merely some embodiments of the present application, and a person of ordinary skill in the art can derive other drawings based on these drawings without inventive effort. In the drawings: Figure 1It is a three-dimensional structural diagram of an aircraft landing gear according to the prior art; wherein 101 is an outer cylinder, 102 is a rotating sleeve, 103 is a resistance strut, 104 is a piston rod, 105 is a tire, 106 is an upper torque arm, and 107 is a lower torque arm.

[0018] Figure 2 It is an overall flow chart of a topology optimization method for complex load conditions of an aircraft landing gear shown in an exemplary embodiment of the present application.

[0019] Figure 3 Schematic diagram of system loads and boundary conditions of an aircraft landing gear shown in an exemplary embodiment of the present application.

[0020] Figure 4 This is a simplified mechanical diagram of a piston rod, a torque arm, and an axle, shown in an exemplary embodiment of the present application; wherein, X 、 Y 、 Z are the three coordinate axes of the spatial coordinate system, O is the top end face of the piston rod, P 1z is the Z-direction load at the contact point between the piston rod and the upper part of the outer cylinder, P 1x is the X-direction load at the contact point between the piston rod and the upper part of the outer cylinder, P 2x is the X-direction load at the contact point between the piston rod and the lower part of the outer cylinder, P 2z is the Z-direction load at the contact point between the piston rod and the lower part of the outer cylinder, a 、 b 、 c All represent rods, corresponding to the piston rod, upper torque arm and lower torque arm respectively; O 1 is the lower end face of the piston rod, 1 is the hinge point between the wheel axle and the lower torque arm, 2 is the hinge point between the upper torque arm and the lower torque arm, 3 is the hinge point between the upper torque arm and the optional sleeve, k The axle loading point.

[0021] Figure 5 It is a structural schematic diagram of the outer cylinder model after the design domain is expanded, shown in an exemplary embodiment of the present application.

[0022] Figure 6 This is a model structure diagram after dividing the design domain and non-design domain, shown in an exemplary embodiment of the present application; wherein (a) is an overall diagram of the design area division, and (b) is a cross-sectional diagram of the design area division.

[0023] Figure 7 1 is a diagram of topology optimization results shown in an exemplary embodiment of the present application; wherein (a) represents the overall result, (b) represents the upper half result, and (c) represents the lower half result.

[0024] Figure 8 1 is an optimized cell density cloud map shown in an exemplary embodiment of the present application; wherein (a) and (b) respectively represent cell density cloud maps of different cell density sizes.

[0025] Figure 9 9 is a structural diagram of a topology optimization device for complex load conditions of an aircraft landing gear shown in an exemplary embodiment of the present application; wherein 91 is a force system simplification module, 92 is a topology optimization module, and 93 is a boundary addition module. DETAILED DESCRIPTION

[0026] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. When the following description refers to the drawings, identical numerals in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0027] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically separate entities. That is, these functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0028] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0029] In this application, "plurality" refers to two or more. "And / or" describes the relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally indicates that the related objects are in an "or" relationship.

[0030] See also Figure 1 , Figure 1 This is a three-dimensional structural diagram of an aircraft landing gear according to the prior art. Figure 1As shown, the aircraft landing gear is a nose landing gear and includes an outer tube 101, a rotating sleeve 102, a resistance strut 103, a piston rod 104, a torque arm, and a tire 105. The torque arm includes an upper torque arm 106 and a lower torque arm 107. One end of the piston rod 104 is connected to the axle of the tire 105, and the piston rod 104 moves only within the outer tube 101. The resistance strut 103 is hinged to the outside of the outer tube 101 to provide support. The rotating sleeve 102 is sleeved onto the outside of the outer tube 101 and connected to the piston rod 104 via the upper torque arm 106 and the lower torque arm 107. The rotation of the rotating sleeve 102, through the transmission of force by the upper torque arm 106 and the lower torque arm 107, causes the piston rod 104 to rise and fall within the outer tube 101, thereby raising and lowering the tire 105.

[0031] It should be noted that although the piston rod 104 extends and retracts in the outer tube 101 , in reality, the piston rod 104 and the outer tube 101 only contact at two locations, the upper and lower parts. Not the entire outer surface of the piston rod 104 interacts with the entire inner surface of the outer tube 101 .

[0032] The present invention provides a topology optimization method for complex load conditions of aircraft landing gear. The topology optimization method can be applied to Figure 1 It is understood that the method proposed in this application is not limited to the landing gear of the aircraft. Figure 1 The application of the aircraft landing gear shown can also be extended to aircraft landing gears of other structural forms. This is only an example and does not limit the present application. Figure 2 , is an overall flow chart of a topology optimization method for complex load conditions of an aircraft landing gear, shown in an exemplary embodiment of the present application. The method includes steps S10 to S30, which are described in detail below.

[0033] S10: Simplified spatial force system.

[0034] In this embodiment, the method of implementing the simplification of the spatial force system in step S10 is as follows: the outer cylinder and the rotating sleeve are regarded as one body, and according to the different strokes of the piston rod, the loads on the resistance support rod, the piston rod, the wheel axle, and the torque arm are translated to the corresponding points of the outer cylinder through the principle of static balance to obtain the load condition after the force system is simplified.

[0035] For example, based on Figure 1 The aircraft landing gear shown, the system load and boundary conditions of the aircraft landing gear are as follows Figure 3In order to simplify the simulation of the stress on the outer cylinder, the outer cylinder 101 and the rotating sleeve 102 are considered as one body during the finite element analysis of the outer cylinder 101. Based on the model of the outer cylinder 101 and the support, and according to the different strokes of the piston rod 104, the loads on the resistance support rod 103, the piston rod 104, the wheel shaft, the torque arm and other components are translated to the corresponding points on the outer cylinder 101 by the principle of static balance, and the following is obtained: Figure 4 The piston rod, torque arm, and axle mechanics diagram shown can be used to simulate real load conditions faster and easier.

[0036] Depend on Figure 3 It can be seen that when the load direction only exists in the xOy plane, according to the principle of static equilibrium and the principle of force translation, seven equations are obtained by calculating the principal vector equilibrium and the principal moment equilibrium, namely the first equation, the second equation, the third equation, the fourth equation, the fifth equation, the sixth equation and the seventh equation.

[0037] in: Taking the piston rod analysis, we get the first equation, the second equation and the third equation, which are expressed as: ; Where, P 1 represents the load at the contact point between the piston rod and the upper part of the outer cylinder. P 2 represents the load at the contact point between the piston rod and the lower part of the outer tube. F kx Indicates the X-direction load at the axle loading point, F 1x Indicates the X-direction load at the hinge point between the wheel axle and the lower torque arm, F O Indicates the end load of the piston rod top, F ky Indicates the Y-axis load at the axle loading point, F 1y Indicates the Y-direction load at the hinge point between the wheel axle and the lower torque arm, Y p1k Indicates the distance between the contact point between the piston rod and the upper part of the outer cylinder and the axle loading point in the Y direction. Y p2k Indicates the distance between the contact point between the piston rod and the lower part of the outer cylinder and the axle loading point in the Y direction. X ok Indicates the distance between the top end face of the piston rod and the axle loading point in the X direction, Y 1k Indicates the distance between the hinge point of the wheel axle and the lower torque arm and the wheel axle loading point in the Y direction, X 1k Indicates the distance between the hinge point between the wheel axle and the lower torque arm and the wheel axle loading point in the X direction.

[0038] It should be noted that, please combine Figure 3 and Figure 4 As shown, the load at the contact point between the piston rod and the upper part of the outer cylinder P 1. Z-direction load at the contact point between the piston rod and the upper part of the outer cylinder P 1z X-axis load at the contact point between the piston rod and the upper part of the outer cylinder P 1x Composition; Load at the contact point between the piston rod and the lower part of the outer tube P 2 X-direction load at the contact point between the piston rod and the lower part of the outer cylinder P 2x and the Z-direction load at the contact point between the piston rod and the lower part of the outer cylinder P 2z composition.

[0039] Overall analysis yields the fourth, fifth, and sixth equations, which are expressed as: ; Where, F 3x Indicates the X-direction load on the hinge point between the upper torque arm and the optional sleeve. F 3y Indicates the Y-axis load on the hinge point between the upper torque arm and the optional sleeve. Y 3k Indicates the distance between the upper torque arm and the optional sleeve hinge point and the axle loading point in the Y direction. X 3k Indicates the distance between the hinge point of the upper torque arm and the optional sleeve and the axle loading point in the X direction.

[0040] At this point, through mechanical analysis, we know that rod C is a two-force rod, so the seventh equation can be expressed as: ; Where, Y 23 Indicates the distance in the Y direction between the hinge point of the upper torque arm and the lower torque arm and the hinge point of the upper torque arm and the optional sleeve. X 23 Indicates the distance in the X direction between the hinge point of the upper torque arm and the lower torque arm and the hinge point of the upper torque arm and the optional sleeve.

[0041] Solve the above seven equations to obtain the load conditions after the force system is simplified.

[0042] At the same time, according to Figure 3 When there is a Z-direction load, the axle loading point k The Z-direction load of the wheel axle loading point k is first translated along the xOz plane to the yOz plane by the principle of force translation, and a Z-direction load is obtained. P 1z 、P 2z On the same plane , and get a pair of rods at the same time a A Z-direction load F is applied to the hinge point 3 between the upper torque arm and the optional sleeve. 3z ,this F 3z Pole a The torque and F kz Torque after translation Based on the principle of static equilibrium and the principle of force translation, the Z-direction loads at the contact point P1 between the piston rod and the upper part of the outer cylinder and the contact point P2 between the piston rod and the lower part of the outer cylinder are calculated. P 1z 、 P 2z At this point, the axle loading point k The Z-direction load is processed.

[0043] When there is a Z-direction load on the upper torque arm and the lower torque arm hinge point 2, the a The torque is equivalent to that of the upper torque arm, and the Z-direction load of the hinge point 2 between the upper torque arm and the lower torque arm is transferred to the hinge point 3 between the upper torque arm and the optional sleeve.

[0044] Based on the above solutions and actual conditions, the loads acting on the contact point P1 between the piston rod and the upper part of the outer tube, the contact point P2 between the piston rod and the lower part of the outer tube, the top end surface O of the piston rod, and the hinge point 3 between the upper torque arm and the optional sleeve are converted into pressure or reaction force acting on the outer tube and the support.

[0045] S20: Topology optimization of aircraft landing gear outer cylinder.

[0046] In this embodiment, the specific process of the aircraft landing gear outer cylinder topology optimization is as follows: constructing an outer cylinder model based on the aircraft landing gear, expanding the design domain of the outer cylinder model while retaining the necessary structural parameters of the structure; dividing the design domain and the non-design domain according to the outer cylinder model after the expanded design domain; meshing the outer cylinder model divided into the design domain and the non-design domain to obtain multiple mesh regions, adding loads and boundary conditions to the design domain in the mesh regions according to the load conditions after the simplified force system, and performing optimization settings with minimum flexibility as the optimization goal; after the optimization settings are completed, performing finite element analysis to obtain a topology optimization result.

[0047] In an exemplary embodiment, the design domain of the model is expanded while retaining the necessary structural parameters of the structure. The expanded model structure is as follows: Figure 5 shown.

[0048] The design domain and the non-design domain are divided according to the expanded design domain model while retaining the necessary structural parameters (such as the size and position of the hole on the outer tube large ear piece). The divided model structure is as follows Figure 6 shown.

[0049] Then, through the following steps S21 to S25, Figure 6 The divided model structure shown is optimized: S21: Define design variables: In this optimization, the design variables are defined as the element density of the elements in the outer cylinder design domain.

[0050] S22: Constraint setting: The upper limit of the constraint volume fraction is 0.3.

[0051] S23: Define the optimization goal: Minimum flexibility is the optimization goal.

[0052] S24: Determine the optimized column formula: ; In the formula, min means minimization, Indicates softness, U T represents the transposed matrix of the overall displacement matrix, U represents the overall displacement matrix, K represents the stiffness matrix, Indicates the unit number, N Indicates the number of units, represents the design variable, P represents the penalty factor, represents the transposed matrix of the unit displacement matrix, represents the unit displacement matrix, represents the element stiffness matrix, Represents the optimized volume, represents the design domain volume, f represents the volume fraction, F represents the load vector, x min Indicates the minimum relative density of the unit.

[0053] In the above optimization formula, Represents a volume constraint, which is used to ensure that the volume after optimization is no larger than the set percentage of the volume before optimization.

[0054] It is an optimization control equation, which gives a range of unit density between 0 and 1. If the design variable is 0, the unit in this part does not exist. If the design variable is 1, the unit exists.

[0055] S25: Optimization parameter setting: The minimum size of this optimization setting is 18mm (6 times the unit size); the penalty factor is 3.

[0056] After completing the above steps S21 to S25, set the corresponding analysis steps based on the finite element model, and complete the load and analysis step settings for 31 working conditions. Use the OptiStruct solver to perform topology optimization on the model. The optimization results are as follows: Figure 7 As shown in the figure, the optimized outer cylinder unit density is as follows Figure 8 As shown. Figure 7 and Figure 8 As can be seen, the material is concentrated in the middle and lower sections of the outer cylinder. This is because under these operating conditions, the outer cylinder primarily bears the bending load. The upper end of the outer cylinder is connected to the body using a linear rib structure at a certain angle. This material distribution minimizes material usage while meeting the operating conditions.

[0057] S30: Semi-automatic addition of boundary conditions based on TCL language.

[0058] The landing gear experiences multiple load conditions during landing, and the piston rod travel varies under different load conditions. Therefore, multiple modeling steps are required during finite element analysis. This repetitive modeling is prone to errors and is time-consuming. To address this issue, this example utilizes the TCL language to redevelop HyperMesh, designing a semi-automated load and travel addition function that can quickly adapt to topology optimization requirements under different travel and load conditions. This tool significantly reduces modeling workload and the incidence of human error, improving analysis efficiency and design accuracy.

[0059] Specifically, step S30 can be implemented by the following steps S31 to S35.

[0060] S31: Tetrahedral meshing of the imported outer cylinder model; S32: Create different materials, properties, and assign the properties to the corresponding meshes; S33: Creating different complexes, load collectors, and load steps; S34: creating a rigid connection unit corresponding to the buffer stroke in the corresponding complex; S35: Create loads for the corresponding working conditions on the corresponding rigid connection elements.

[0061] It should be noted that the rigid link element (or RBE3 element) is a special type of link element used in finite element analysis. It is used to describe the relationship between multiple nodes and constrain the displacement and rotation of multiple nodes together.

[0062] See also Figure 9 , Figure 9 This is a structural diagram of a topology optimization device for complex load conditions of an aircraft landing gear, shown in an exemplary embodiment of the present application. Another aspect of the present invention provides a topology optimization device for complex load conditions of an aircraft landing gear, the aircraft landing gear comprising an outer tube, a rotating sleeve, a resistance strut, a torque arm, a piston rod, and a tire, the torque arm comprising an upper torque arm and a lower torque arm, the rotating sleeve disposed on the outside of the outer tube, the resistance strut disposed on the outside of the outer tube, the rotating sleeve connected to the piston rod via the upper and lower torque arms, the piston rod movably disposed within the sleeve, one end of the piston rod disposed on the wheel axle of the tire, the device comprising: The force system simplification module 91 is configured to treat the outer cylinder and the rotating sleeve as a whole. Based on the different strokes of the piston rod and the principle of static equilibrium, the loads on the resistance support rod, piston rod, wheel axle, and torque arm are translated to the corresponding points on the outer cylinder to obtain the simplified load situation of the force system. a topology optimization module 92 configured to construct an outer cylinder model based on the aircraft landing gear, expand the design domain of the outer cylinder model while retaining necessary structural parameters; divide the outer cylinder model after the expanded design domain into a design domain and a non-design domain; mesh the outer cylinder model divided into the design domain and the non-design domain to obtain a plurality of mesh regions; add loads and boundary conditions to the design domain in the mesh regions according to the load conditions after the simplified force system, and perform optimization settings with minimum flexibility as the optimization goal; and after the optimization settings are completed, perform finite element analysis to obtain a topology optimization result. The boundary adding module 93 is configured to implement semi-automatic addition of boundary conditions based on TCL language when performing finite element analysis.

[0063] It should be noted that the topology optimization device for complex load conditions of aircraft landing gear provided in the above embodiment and the topology optimization method for complex load conditions of aircraft landing gear provided in the above embodiment belong to the same concept, and the specific manner of executing the steps has been described in detail in the method embodiment and will not be repeated here.

[0064] Another aspect of the present application provides an electronic device, including: a controller; a memory for storing one or more programs, which, when executed by the controller, executes the topology optimization method for complex load conditions of aircraft landing gear in the above-mentioned embodiments.

[0065] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a computer program for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication portion, and / or installed from a removable medium. When the computer program is executed by a central processing unit (CPU), various functions defined in the system of the present application are executed.

[0066] It should be noted that the computer-readable medium shown in the embodiments of the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media can include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In the present application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable computer program. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. A computer program embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, or any suitable combination thereof.

[0067] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. Among them, each box in the flowchart or block diagram can represent a module, program segment, or part of the code, and the above-mentioned module, program segment, or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0068] The modules / units described in the embodiments of this application may be implemented in software or hardware, and the described units may also be provided in a processor. The names of these modules / units do not, in some cases, limit the modules / units themselves.

[0069] Another aspect of the present application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned method for topological optimization of aircraft landing gear under complex load conditions. The computer-readable storage medium may be included in the electronic device described in the above embodiments, or may exist independently and not be incorporated into the electronic device.

[0070] Another aspect of the present application provides a computer program product or computer program, comprising computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the method for topology optimization of aircraft landing gear under complex load conditions provided in the various embodiments described above.

[0071] According to one aspect of an embodiment of the present application, a computer system is further provided, including a central processing unit (CPU), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) or a program loaded from a storage portion into a random access memory (RAM), such as executing the method in the above embodiment. Various programs and data required for system operation are also stored in the RAM. The CPU, ROM, and RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.

[0072] The following components are connected to the I / O interface: an input section including a keyboard, mouse, etc.; an output section including a cathode ray tube (CRT), liquid crystal display (LCD), and speakers; a storage section including a hard disk; and a communication section including a network interface card such as a LAN (Local Area Network) card and a modem. The communication section performs communication processing via a network such as the Internet. A drive is also connected to the I / O interface as needed. Removable media such as magnetic disks, optical disks, magneto-optical disks, semiconductor memories, etc. are installed in the drive as needed so that computer programs read from them can be installed into the storage section as needed.

[0073] The above content is only a preferred exemplary embodiment of the present application and is not intended to limit the implementation scheme of the present application. Ordinary technicians in this field can easily make corresponding changes or modifications based on the main ideas and spirit of the present application. Therefore, the scope of protection of the present application shall be based on the scope of protection required by the claims.

Claims

1. A topological optimization method for complex load conditions of an aircraft landing gear, the aircraft landing gear comprising an outer tube, a rotating sleeve, a resistance strut, a torque arm, a piston rod and a tire, the torque arm comprising an upper torque arm and a lower torque arm, the rotating sleeve is arranged on the outside of the outer tube, the resistance strut is arranged on the outside of the outer tube, the rotating sleeve is connected to the piston rod through the upper torque arm and the lower torque arm, the piston rod is movably arranged in the outer tube, one end of the piston rod is arranged on the wheel axle of the tire, characterized in that, The method comprises: The outer cylinder and the rotating sleeve are regarded as one body. According to the different strokes of the piston rod, the loads on the resistance support rod, the piston rod, the axle and the torque arm are translated to the corresponding points of the outer cylinder through the principle of static balance to obtain the load situation after the force system is simplified. An outer cylinder model is constructed based on the aircraft landing gear, and a design domain of the outer cylinder model is expanded while retaining necessary structural parameters of the structure; According to the outer cylinder model after the design domain is expanded, the design domain and the non-designable domain are divided; Meshing the outer cylinder model that divides the design domain and the non-designable domain to obtain a plurality of mesh regions, adding loads and boundary conditions to the design domain in the mesh regions according to the load conditions after the force system is simplified, and performing optimization settings with minimum flexibility as the optimization goal; After the optimization settings are completed, finite element analysis is performed to obtain topology optimization results; When performing finite element analysis, boundary conditions are semi-automatically added based on TCL language.

2. The topology optimization method for complex load conditions of aircraft landing gear according to claim 1, characterized in that: The outer cylinder and the rotating sleeve are considered as one body. According to the different strokes of the piston rod, the loads on the resistance support rod, piston rod, axle and torque arm are translated to the corresponding points of the outer cylinder through the principle of static balance, and the load situation after the force system is simplified is obtained, including: According to the principle of static balance and the principle of force translation, seven equations are obtained by calculating the principal vector balance and the principal moment balance, namely the first equation, the second equation, the third equation, the fourth equation, the fifth equation, the sixth equation and the seventh equation; among them: Taking the piston rod analysis, we get the first equation, the second equation and the third equation, which are expressed as: ； In the formula, P 1 represents the load at the contact point between the piston rod and the upper part of the outer tube. P 2 represents the load at the contact point between the piston rod and the lower part of the outer tube. F kx represents the X-direction load at the axle loading point, F 1x Indicates the X-direction load at the hinge point between the wheel axle and the lower torque arm, F O Indicates the end load on the piston rod top. F ky represents the Y-axis load at the axle loading point, F 1y Indicates the Y-axis load at the hinge point between the wheel axle and the lower torque arm, Y p1k Indicates the distance between the contact point between the piston rod and the upper part of the outer cylinder and the axle loading point in the Y direction. Y p2k Indicates the distance between the contact point between the piston rod and the lower part of the outer cylinder and the axle loading point in the Y direction. X ok Indicates the distance between the top end of the piston rod and the axle loading point in the X direction, Y 1k Indicates the distance between the hinge point between the wheel axle and the lower torque arm and the wheel axle loading point in the Y direction, X 1k Indicates the distance between the hinge point between the wheel axle and the lower torque arm and the wheel axle loading point in the X direction; Overall analysis yields the fourth, fifth, and sixth equations, which are expressed as: ； In the formula, F 3x Indicates the X-axis load on the hinge point between the upper torque arm and the optional sleeve. F 3y Indicates the Y-axis load on the hinge point between the upper torque arm and the optional sleeve. Y 3k Indicates the distance between the upper torque arm and the optional sleeve hinge point and the axle loading point in the Y direction. X 3k Indicates the distance between the upper torque arm and the optional sleeve hinge point and the axle loading point in the X direction; The seventh equation is expressed as: ； In the formula, Y 23 Indicates the distance between the hinge point of the upper torque arm and the lower torque arm and the hinge point of the upper torque arm and the optional sleeve in the Y direction. X 23 Indicates the distance between the hinge point of the upper torque arm and the lower torque arm and the hinge point of the upper torque arm and the optional sleeve in the X direction; Based on the seven equations, the load condition of the simplified force system is obtained.

3. The topology optimization method for complex load conditions of aircraft landing gear according to claim 1, characterized in that: The optimization setting is carried out with the minimum flexibility as the optimization goal, including: Set the cell density of the cells in the design domain as a variable; Set constraints, and the upper limit of the constraint volume fraction is 0.3; Taking the minimum flexibility as the optimization goal, the optimization formula is constructed; Based on the optimization formula and the set constraints, the optimization parameters are set for optimization to obtain the optimal cell density of the cells in the design domain; wherein the optimization parameters include the minimum size of the optimization and the penalty factor.

4. The topology optimization method for complex load conditions of aircraft landing gear according to claim 3, characterized in that: The optimization column is expressed as: ； In the formula, min means minimization, Indicates softness, U T represents the transposed matrix of the overall displacement matrix, U represents the overall displacement matrix, K represents the stiffness matrix, Indicates the unit number, N Indicates the number of units, represents the design variable, P represents the penalty factor, represents the transposed matrix of the unit displacement matrix, represents the unit displacement matrix, represents the element stiffness matrix, Represents the optimized volume, represents the design domain volume, f represents the volume fraction, F represents the load vector, x min Indicates the minimum relative density of the unit.

5. The topology optimization method for complex load conditions of aircraft landing gear according to claim 3, characterized in that: The optimized minimum size is 6 times the cell size.

6. The topology optimization method for complex load conditions of aircraft landing gear according to claim 1, characterized in that: After the optimization settings are completed, finite element analysis is performed to obtain topology optimization results, including: On the basis of the finite element model, the loads and analysis steps of various working conditions are set, and the model is topologically optimized using the finite element solver to obtain the topological optimization results.

7. The topology optimization method for complex load conditions of aircraft landing gear according to claim 6, characterized in that: When performing finite element analysis, boundary conditions are semi-automatically added based on TCL language, including: Perform tetrahedral meshing on the imported outer cylinder model; Create different materials, properties, and assign the properties to the corresponding tetrahedral meshes; Create different complexes, load collectors, and load steps; Creating a rigid connection unit corresponding to the buffer stroke in the corresponding complex; Create loads for the corresponding load cases on the corresponding rigid connection elements.

8. A topological optimization device for complex load conditions of an aircraft landing gear, the aircraft landing gear comprising an outer tube, a rotating sleeve, a resistance strut, a torque arm, a piston rod and a tire, the torque arm comprising an upper torque arm and a lower torque arm, the rotating sleeve is arranged on the outside of the outer tube, the resistance strut is arranged on the outside of the outer tube, the rotating sleeve is connected to the piston rod through the upper torque arm and the lower torque arm, the piston rod is movably arranged in the outer tube, one end of the piston rod is arranged on the wheel axle of the tire, characterized in that, The device comprises: The force system simplification module is configured to regard the outer cylinder and the rotating sleeve as one body. According to the different strokes of the piston rod, the loads on the resistance support rod, the piston rod, the wheel axle and the torque arm are translated to the corresponding points of the outer cylinder through the principle of static balance to obtain the load situation after the force system is simplified. A topology optimization module is configured to construct an outer cylinder model based on the aircraft landing gear, expand the design domain of the outer cylinder model while retaining the necessary structural parameters of the structure; divide the design domain and the non-design domain according to the outer cylinder model after the design domain is expanded; mesh the outer cylinder model divided into the design domain and the non-design domain to obtain multiple mesh areas, add loads and boundary conditions to the design domain in the mesh area according to the load conditions after the force system is simplified, and perform optimization settings with minimum flexibility as the optimization goal; after the optimization settings are completed, perform finite element analysis to obtain topology optimization results; The boundary adding module is configured to implement semi-automatic adding of boundary conditions based on TCL language when performing finite element analysis.

9. An electronic device, characterized in that: include: Controller; A memory for storing one or more programs, which, when executed by the controller, enables the controller to implement the topology optimization method for complex load conditions of an aircraft landing gear as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: Computer-readable instructions are stored thereon, and when the computer-readable instructions are executed by a processor of a computer, the computer is caused to execute the topology optimization method for complex load conditions of an aircraft landing gear according to any one of claims 1 to 7.

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