Aircraft engine hanging connection structure modeling method

Abstract

The invention belongs to the technical field of aircraft engine hanging structure modeling, and particularly relates to an aircraft engine hanging connection structure modeling method which comprises the steps that 1, finite element models of a front hanging connector, a rear hanging connector, a left pull rod, a left pull rod connector, a right pull rod and a right pull rod connector are established and assembled into a hanging structure finite element model; 2, establishing an engine simplified model according to force transmission analysis; 3, accessing the engine simplified model to the finite element model of the hanging structure; and 4, accessing the finite element model of the hanging structure to the finite element model of the machine body.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft engine suspension structure modeling, and specifically relates to a method for modeling an aircraft engine suspension connection structure. Background Art

[0002] The engine suspension structure is the connection structure between the engine and the aircraft body. It bears the engine inertia load, thrust and reverse thrust load, and transmits them to the fuselage.

[0003] The engine suspension structure mainly includes a front suspension joint 1, a rear suspension joint 2, a left tie rod 3, a left tie rod joint 4, a right tie rod 5, and a right tie rod joint 6, wherein the front suspension joint 1 and the rear suspension joint 2 are connected to the body and the engine 7 through fasteners; the left tie rod 3 and the right tie rod 5 are connected to the engine 7 through fasteners, the left tie rod joint 4 and the right tie rod joint 6 are connected to the body through fasteners, and the left tie rod 3 and the left tie rod joint 4 are connected by fasteners, and the right tie rod 5 and the right tie rod joint 6 are connected by fasteners, such as Figure 1 shown.

[0004] Once the engine suspension structure is damaged, it will seriously endanger flight safety. Therefore, in aircraft design and analysis, the suspension structure is generally modeled using three-dimensional solid units, requiring each part and bolt to be solid modeled. Although the calculation accuracy is high, the modeling process is complicated and the calculation efficiency is low. If the three-dimensional solid model of the suspension structure is brought into the full aircraft model for full-aircraft solution, the scale of the full-aircraft model will be extremely large.

[0005] This application is proposed in view of the above-mentioned technical defects. Summary of the invention

[0006] The purpose of the present application is to provide a modeling method for an aircraft engine suspension connection structure to overcome or alleviate at least one of the known technical deficiencies.

[0007] The technical solution of this application is:

[0008] A modeling method for an aircraft engine suspension connection structure, comprising:

[0009] Step 1: Establish finite element models of the front suspension joint, the rear suspension joint, the left tie rod, the left tie rod joint, the right tie rod, and the right tie rod joint, and assemble them into a suspension structure finite element model;

[0010] Step 2: Establish a simplified engine model based on force transmission analysis;

[0011] Step 3: Connect the simplified engine model to the finite element model of the suspension structure;

[0012] Step 4: Connect the finite element model of the suspension structure to the finite element model of the fuselage.

[0013] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, step 1 includes:

[0014] S11, performing finite element mesh division on the front hanging joint, the rear hanging joint, the left tie rod, the left tie rod joint, the right tie rod, and the right tie rod joint, simplifying the front hanging joint, the rear hanging joint, the left tie rod joint, and the right tie rod joint into two-dimensional plate elements, and simplifying the left tie rod and the right tie rod into beam elements;

[0015] S12, determining the geometric dimensions and material properties of the left tie rod, the left tie rod joint, the right tie rod, and the right tie rod joint, as well as the dimensions and material properties of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint;

[0016] S13, calculating the elastic compliance of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint;

[0017] S14. Calculate the stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint;

[0018] S15, establishing two coincident nodes A and B at the connection between the left tie rod and the left tie rod joint, and forming rigid body elements with the nodes around the left tie rod and the left tie rod joint and the points A and B;

[0019] Two coincident nodes C and D are established at the connection between the right tie rod and the right tie rod joint, and the nodes around the right tie rod and the right tie rod joint and points C and D are formed into rigid body elements, which can be specifically RBE2 rigid body elements;

[0020] S16. Connect the coincident nodes A and B to form a spring element, and connect the coincident nodes C and D to form a spring element, and assign a value to the stiffness of the spring element using the calculated stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint.

[0021] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, in S12, the geometric dimensions of the left tie rod, the left tie rod joint, the right tie rod, and the right tie rod joint are determined, including the tie rod thickness t 1 , Tie rod joint thickness t 2 , material properties include elastic modulus E;

[0022] Determine the fastener dimensions between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint, including the diameter d, and the material properties including the elastic modulus E 1 .

[0023] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, S13 is specifically:

[0024]

[0025] in,

[0026] C is the elastic flexibility of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint;

[0027] K e It is the material correction factor of the fastener material between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint.

[0028] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, in S13, for aluminum material, K e Take 1; for titanium, K e Take 0.77; for steel, K e Take 0.67.

[0029] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, in S14, the stiffness of the fasteners between the left tie rod and the left tie rod joint and between the right tie rod and the right tie rod joint is calculated, including shear stiffness and tensile stiffness.

[0030] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, S14 is specifically:

[0031]

[0032]

[0033] in,

[0034] K 1 is the shear stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint;

[0035] K 2 is the tensile stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint;

[0036] A is the cross-sectional area of ​​the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint.

[0037] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, in S15, the left tie rod, the nodes around the left tie rod joint, and the point A and the point B are formed into a rigid element, specifically an RBE2 rigid element;

[0038] The right tie rod, the nodes around the right tie rod joint, point C and point D form a rigid body element, specifically an RBE2 rigid body element.

[0039] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, S16 is specifically:

[0040] Call the MSC.NASTRAN program card and use the CELAS2 statement to connect the coincident nodes A and B to form a spring element, and connect the coincident nodes C and D to form a spring element. Use the calculated shear stiffness and tensile stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint to assign values ​​to the shear stiffness and tensile stiffness of the spring element.

[0041] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, step 2 includes:

[0042] S21, establishing a node E at the center of gravity of the engine;

[0043] S22, establishing a node F at the connection between the engine and the left tie rod, a node G at the connection between the engine and the right tie rod, a node H at the connection between the engine and the front suspension joint, and a node I at the connection between the engine and the rear suspension joint;

[0044] S23, forming a plane through points F, G and H, and establishing a node point J at the centroid of the plane;

[0045] S24. A rigid body element is formed by point J and point E, and a rigid body element is formed by point I and point E, so as to construct a simplified model of the engine.

[0046] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, in S24, a rigid body element is formed by point J and point E, and a rigid body element is formed by point I and point E, point J and point I are slave points, and point E is an active point.

[0047] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, step three is specifically:

[0048] Points F and J form a rigid body element, points G and J form a rigid body element, and points H and J form a rigid body element.

[0049] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, in step three, points F and J form a rigid body element, points G and J form a rigid body element, and points H and J form a rigid body element, points F, G, and H are slave points, and point J is an active point.

[0050] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, step 4 includes:

[0051] S41. Calculate the stiffness of the fasteners between the body and the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint;

[0052] S42. Establish FAST elements in the two-dimensional units at the connection between the fuselage and the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint to calculate the stiffness of the fasteners between the fuselage and the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint, and assign stiffness values ​​to the FAST elements.

[0053] According to at least one embodiment of the present application, in the above-mentioned aircraft engine suspension connection structure modeling method, in S41, the stiffness of the fasteners between the body and the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint is calculated, including shear stiffness and tensile stiffness;

[0054] In S42, the stiffness of the FAST element is assigned based on the calculated stiffness of the fasteners between the fuselage and the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint, including the shear stiffness and the tensile stiffness.

[0055] This application has at least the following beneficial technical effects:

[0056] A modeling method for an aircraft engine suspension connection structure is provided. Based on the force transmission characteristics of the connection structure and taking into account the stiffness of the connector, the model is simplified, which can reduce the complexity of modeling the aircraft engine suspension connection structure. The method is used for solving the finite element model of the entire aircraft, has high calculation efficiency, and can accurately reflect the tensile stiffness, shear stiffness and force transmission characteristics of the connection structure, can meet engineering needs, significantly shorten the calculation time, and improve the calculation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is a schematic diagram of an engine suspension structure provided in an embodiment of the present application;

[0058] Figure 2 is a schematic diagram of a modeling method for an aircraft engine suspension connection structure provided in an embodiment of the present application;

[0059] Figure 3is a schematic diagram of a finite element model of a suspension structure provided in an embodiment of the present application;

[0060] Figure 4 is a schematic diagram of a rigid element of a tie rod and a tie rod joint provided in an embodiment of the present application;

[0061] Figure 5 It is a schematic diagram of establishing a simplified engine model and connecting to a finite element model of a suspension structure provided in an embodiment of the present application;

[0062] Figure 6 is a schematic diagram of connecting the finite element model of the suspension structure to the finite element model of the body provided in an embodiment of the present application;

[0063] in:

[0064] 1-Front suspension joint, 2-Rear suspension joint, 3-Left tie rod, 4-Left tie rod joint, 5-Right tie rod, 6-Right tie rod joint, 7-Engine, 8-Left tie rod finite element model, 9-Right tie rod finite element model, 10-Left tie rod joint finite element model, 11-Right tie rod joint finite element model, 12-Front suspension joint finite element model, 13-Rear suspension joint finite element model, 14-Left tie rod and engine connection, 15-Right tie rod and engine connection, 16-Front suspension joint and engine connection, 17-Rear suspension joint and engine connection, 18-engine center of gravity, 19-engine section center of mass, 20-FASTER element on the left tie rod joint, 21-FASTER element on the front suspension joint, 22-FASTER element on the right tie rod joint, 23-FASTER element on the rear suspension joint, 24-rigid body element at the left tie rod and tie rod joint, 25-rigid body element at the right tie rod and tie rod joint, 26-rigid body element at the engine and rear suspension joint, 27-rigid body element at the front external connection and the center of mass of the engine section, 28-rigid body element at the center of gravity of the engine and the center of mass of the engine section, 29-finite element model of the fuselage.

[0065] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be construed as limitations on the present application. DETAILED DESCRIPTION

[0066] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0067] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the usual meanings understood by those of ordinary skill in the art to which this application belongs. The words used in the description of this application to indicate orientation are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application indicates that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0068] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0069] A modeling method for aircraft engine suspension connection structure, such as Figure 2 shown.

[0070] Step 1: Establish finite element models of the front suspension joint, rear suspension joint, left tie rod, left tie rod joint, right tie rod, and right tie rod joint, and assemble them into a suspension structure finite element model, such as Figure 3 shown.

[0071] S11. Perform finite element mesh division on the front suspension joint, the rear suspension joint, the left tie rod, the left tie rod joint, the right tie rod, and the right tie rod joint. Simplify the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint into two-dimensional plate units, and simplify the left tie rod and the right tie rod into beam units.

[0072] S12. Determine the geometric dimensions and material properties of the left tie rod, the left tie rod joint, the right tie rod, and the right tie rod joint, as well as the dimensions and material properties of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint.

[0073] The left side tie rod and the left side tie rod joint are symmetrical structures with the right side tie rod and the right side tie rod joint, and have the same geometric dimensions, material properties and fasteners.

[0074] The geometrical dimensions of the left tie rod, the left tie rod joint, the right tie rod, and the right tie rod joint include the tie rod thickness t 1 , Tie rod joint thickness t 2 , material properties include the elastic modulus E.

[0075] The fastener dimensions between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint include the diameter d, and the material properties include the elastic modulus E 1 .

[0076] In a specific example, t 1 =3mm, t 2 =4mm, E=71000MPa, d=6mm, E 1 =109000MPa.

[0077] S13. Calculate the elastic compliance of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint:

[0078]

[0079] in,

[0080] C is the elastic flexibility of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint;

[0081] K e K is the material correction factor of the fastener material between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint. For aluminum, K e =1, for titanium, K e =0.77. For steel, K e =0.67.

[0082] With the above values, it is calculated that the elastic compliance coefficient C of the fasteners between the left tie rod and the left tie rod joint and between the right tie rod and the right tie rod joint is 4.12E-5mm / N.

[0083] S14. Calculate the stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint.

[0084] The stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint, including shear stiffness and tensile stiffness.

[0085]

[0086]

[0087] in,

[0088] K 1 is the shear stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint;

[0089] K 2is the tensile stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint;

[0090] A is the cross-sectional area of ​​the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint.

[0091] Using the above values, the shear stiffness K of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint is calculated: 1 is 24265.91N / mm, tensile stiffness K 2 It is 410712N / mm.

[0092] S15, establishing two coincident nodes A and B at the connection between the left tie rod and the left tie rod joint, and forming a rigid body element with the nodes around the left tie rod and the left tie rod joint and the points A and B, which may be specifically an RBE2 rigid body element;

[0093] Two coincident nodes C and D are established at the connection between the right tie rod and the right tie rod joint, and the nodes around the right tie rod and the right tie rod joint and points C and D are formed into rigid body elements, which can be RBE2 rigid body elements, such as Figure 4 shown.

[0094] S16. Connect the coincident nodes A and B to form a spring element, and connect the coincident nodes C and D to form a spring element, and assign a value to the stiffness of the spring element using the calculated stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint.

[0095] Call the MSC.NASTRAN program card and use the CELAS2 statement to connect the coincident nodes A and B to form a spring element, and connect the coincident nodes C and D to form a spring element. Use the calculated shear stiffness and tensile stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint to assign values ​​to the shear stiffness and tensile stiffness of the spring element.

[0096] Step 2: Establish a simplified engine model based on force transmission analysis.

[0097] S21. Establish a node E at the center of gravity of the engine.

[0098] S22, establishing a node F at the connection between the engine and the left tie rod, a node G at the connection between the engine and the right tie rod, a node H at the connection between the engine and the front suspension joint, and a node I at the connection between the engine and the rear suspension joint.

[0099] S23, forming a plane through points F, G and H, and establishing a node point J at the centroid of the plane;

[0100] S24, forming a rigid body element with point J and point E, and forming a rigid body element with point I and point E, and constructing a simplified engine model, such as Figure 5 shown.

[0101] Points J and I are slave points, and point E is the active point.

[0102] Step 3: Connect the simplified engine model to the finite element model of the suspension structure.

[0103] Points F and J form a rigid body element, points G and J form a rigid body element, and points H and J form a rigid body element. The simplified engine model is connected to the finite element model of the suspension structure, such as Figure 5 shown.

[0104] Points F, G, and H are slave points, and point J is the active point.

[0105] Step 4: Connect the finite element model of the suspension structure to the finite element model of the fuselage.

[0106] S41. Calculate the stiffness of the fasteners between the body and the front suspension joint, rear suspension joint, left tie rod joint, and right tie rod joint, including shear stiffness and tensile stiffness.

[0107] The machine body and the front suspension joint, the rear suspension joint, the left tie rod joint and the right tie rod joint can adopt the same connection structure, and the geometric dimensions, material properties and fasteners used are the same.

[0108] For details, please refer to calculation S12 to S14 of the stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint.

[0109] In a specific example, the body thickness t′ 1 =3mm, joint thickness t' 2 =4mm, body elastic modulus E'=71000MPa, fastener diameter d'=6mm, fastener elastic modulus E 1 '=109000Mpa, the shear stiffness K of the fastener is calculated 1 ' is 24265.91N / mm, tensile stiffness K 2 ' is 410712N / mm.

[0110] S42. Establish FAST elements in the two-dimensional units at the connection between the fuselage and the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint, calculate the stiffness of the fasteners between the fuselage and the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint, and assign stiffness values ​​to the FAST elements, including shear stiffness and tensile stiffness, so as to connect the finite element model of the suspension structure to the finite element model of the fuselage, such as Figure 6 shown.

[0111] The aircraft engine suspension connection structure modeling method disclosed in the above embodiment is based on the force transmission characteristics of the connection structure and takes into account the stiffness of the connecting parts to simplify the model, which can reduce the complexity of modeling the aircraft engine suspension connection structure. It is used for solving the finite element model of the entire aircraft, has high computational efficiency, and can accurately reflect the tensile stiffness, shear stiffness and force transmission characteristics of the connection structure, can meet engineering requirements, significantly shorten the calculation time, and improve the calculation efficiency.

[0112] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A modeling method for an aircraft engine suspension connection structure, characterized in that: include: Step 1: Establish finite element models of the front suspension joint, the rear suspension joint, the left tie rod, the left tie rod joint, the right tie rod, and the right tie rod joint, and assemble them into a suspension structure finite element model; Step 2: Establish a simplified engine model based on force transmission analysis; Step 3: Connect the simplified engine model to the finite element model of the suspension structure; Step 4: Connect the finite element model of the suspension structure to the finite element model of the fuselage.

2. The aircraft engine suspension connection structure modeling method according to claim 1, characterized in that: Step one includes: S11, performing finite element mesh division on the front hanging joint, the rear hanging joint, the left tie rod, the left tie rod joint, the right tie rod, and the right tie rod joint, simplifying the front hanging joint, the rear hanging joint, the left tie rod joint, and the right tie rod joint into two-dimensional plate elements, and simplifying the left tie rod and the right tie rod into beam elements; S12, determining the geometric dimensions and material properties of the left tie rod, the left tie rod joint, the right tie rod, and the right tie rod joint, as well as the dimensions and material properties of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint; S13, calculating the elastic compliance of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint; S14. Calculate the stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint; S15, establishing two coincident nodes A and B at the connection between the left tie rod and the left tie rod joint, and forming rigid body elements with the nodes around the left tie rod and the left tie rod joint and the points A and B; Two coincident nodes C and D are established at the connection between the right tie rod and the right tie rod joint, and the nodes around the right tie rod and the right tie rod joint and points C and D are formed into rigid body elements, which can be specifically RBE2 rigid body elements; S16. Connect the coincident nodes A and B to form a spring element, and connect the coincident nodes C and D to form a spring element, and assign a value to the stiffness of the spring element using the calculated stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint.

3. The aircraft engine suspension connection structure modeling method according to claim 2 is characterized in that: In S12, the geometric dimensions of the left tie rod, the left tie rod joint, the right tie rod, and the right tie rod joint are determined, including the tie rod thickness t1 and the tie rod joint thickness t2, and the material properties include the elastic modulus E; Determine the dimensions of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint, including the diameter d, and the material properties, including the elastic modulus E1.

4. The aircraft engine suspension connection structure modeling method according to claim 3 is characterized in that: S13 is specifically: in, C is the elastic flexibility of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint; K e It is the material correction factor of the fastener material between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint.

5. The aircraft engine suspension connection structure modeling method according to claim 4, characterized in that: In S13, for aluminum, K e Take 1; for titanium, K e Take 0.77; for steel, K e Take 0.

67.

6. The aircraft engine suspension connection structure modeling method according to claim 5, characterized in that: In S14, the stiffness of the fasteners between the left tie rod and the left tie rod joint and between the right tie rod and the right tie rod joint is calculated, including shear stiffness and tensile stiffness.

7. The aircraft engine suspension connection structure modeling method according to claim 6, characterized in that: S14 is specifically: in, K1 is the shear stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint; K2 is the tensile stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint; A is the cross-sectional area of ​​the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint.

8. The aircraft engine suspension connection structure modeling method according to claim 7, characterized in that: In S15, the left tie rod, the nodes around the left tie rod joint, point A and point B are formed into a rigid body element, specifically an RBE2 rigid body element; The right tie rod, the nodes around the right tie rod joint, point C and point D form a rigid body element, specifically an RBE2 rigid body element.

9. The aircraft engine suspension connection structure modeling method according to claim 8, characterized in that: S16 is specifically: Call the MSC.NASTRAN program card and use the CELAS2 statement to connect the coincident nodes A and B to form a spring element, and connect the coincident nodes C and D to form a spring element. Use the calculated shear stiffness and tensile stiffness of the fasteners between the left tie rod and the left tie rod joint, and between the right tie rod and the right tie rod joint to assign values ​​to the shear stiffness and tensile stiffness of the spring element.

10. The aircraft engine suspension connection structure modeling method according to claim 9, characterized in that: Step 2 includes: S21, establishing a node E at the center of gravity of the engine; S22, establishing a node F at the connection between the engine and the left tie rod, a node G at the connection between the engine and the right tie rod, a node H at the connection between the engine and the front suspension joint, and a node I at the connection between the engine and the rear suspension joint; S23, forming a plane through points F, G and H, and establishing a node point J at the centroid of the plane; S24. A rigid body element is formed by point J and point E, and a rigid body element is formed by point I and point E, so as to construct a simplified model of the engine.

11. The aircraft engine suspension connection structure modeling method according to claim 10, characterized in that: In S24, a rigid body element is formed by point J and point E, and a rigid body element is formed by point I and point E. Point J and point I are slave points, and point E is an active point.

12. The aircraft engine suspension connection structure modeling method according to claim 11, characterized in that: Step three is as follows: Points F and J form a rigid body element, points G and J form a rigid body element, and points H and J form a rigid body element.

13. The aircraft engine suspension connection structure modeling method according to claim 12, characterized in that: In step three, a rigid body element is formed by points F and J, a rigid body element is formed by points G and J, and a rigid body element is formed by points H and J. Points F, G, and H are slave points, and point J is an active point.

14. The aircraft engine suspension connection structure modeling method according to claim 13, characterized in that: Step 4 includes: S41. Calculate the stiffness of the fasteners between the body and the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint; S42. Establish FAST elements in the two-dimensional units at the connection between the fuselage and the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint to calculate the stiffness of the fasteners between the fuselage and the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint, and assign stiffness values ​​to the FAST elements.

15. The aircraft engine suspension connection structure modeling method according to claim 14, characterized in that: In S41, the stiffness of the fasteners between the body and the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint is calculated, including the shear stiffness and the tensile stiffness; In S42, the stiffness of the FAST element is assigned based on the calculated stiffness of the fasteners between the fuselage and the front suspension joint, the rear suspension joint, the left tie rod joint, and the right tie rod joint, including the shear stiffness and the tensile stiffness.

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