Method and device for calculating grounding load of single-side wing of airplane

Abstract

The invention provides a method and device for calculating the ground contact load of a single-side wing of an aircraft, and belongs to the technical field of aircraft ground load calculation, and the method comprises the steps: building an aircraft motion analysis model when the single-side wing of the aircraft is in ground contact, and obtaining a rotation angular velocity expression when the wing is in ground contact according to the aircraft motion analysis model; assumed conditions are constructed, a wingtip load calculation process after the wing touches the ground is established based on the assumed conditions, and a rotation angle expression when the wing touches the ground and an expression of bearing reaction force of the ground to the wing are obtained; determining parameters required for calculating the ground contact load of the single-side wing, and acquiring numerical values of the parameters; and on the basis of the numerical values of the parameters, the rotation angular velocity expression when the wing touches the ground, the rotation angle expression when the wing touches the ground and the bearing reaction expression of the ground to the wing, calculating to obtain the bearing reaction of the ground to the wing when the single-side wing touches the ground.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aircraft ground load calculation, and particularly relates to a method and device for calculating a single-wing ground load of an aircraft. BACKGROUND

[0002] When an aircraft is in an emergency landing, an extreme situation may occur in which one main landing gear is lowered and the other main landing gear fails to be normally lowered due to a fault. At this time, the aircraft tilts to the side where the main landing gear is not lowered, and finally causes the wing on this side to touch the ground. Correspondingly, when the single-wing touches the ground, the ground will generate a force on the wing. How to more accurately calculate the single-wing ground load is of great significance to the design of the wing structure of the aircraft.

[0003] In the prior art, the load when the single-wing touches the ground can generally be calculated by a multi-body dynamics simulation analysis method. In engineering, a commercial multi-body dynamics software is usually used to establish a simulation analysis model of the aircraft body and the landing gear, and to simulate external forces such as aerodynamic force and moment, so as to carry out dynamic simulation of the single-wing ground process of the aircraft, and thus to extract the ground load on the wing. However, this method has high requirements on the quality of the model, the simulation analysis period is relatively long, and the result accuracy is also limited. SUMMARY

[0004] The purpose of the present application is to provide a method and device for calculating a single-wing ground load of an aircraft to solve or alleviate at least one problem in the background art.

[0005] The technical solution of the present application is: a method for calculating a single-wing ground load of an aircraft, comprising:

[0006] establishing an aircraft motion analysis model in a single-wing ground condition of the aircraft, and obtaining an expression of a rotation angular velocity of the wing when the wing touches the ground according to the aircraft motion analysis model;

[0007] constructing a hypothetical condition, establishing a wing tip load calculation process after the wing touches the ground based on the hypothetical condition, and obtaining an expression of a rotation angle of the wing when the wing touches the ground and an expression of a ground reaction force on the wing;

[0008] determining parameters required for calculating the single-wing ground load, and obtaining numerical values of the parameters;

[0009] based on the numerical values of the parameters and the expression of the rotation angular velocity of the wing when the wing touches the ground, the expression of the rotation angle of the wing when the wing touches the ground, and the expression of the ground reaction force on the wing, calculating a ground reaction force on the wing when the single-wing touches the ground.

[0010] Preferably, the process of establishing the aircraft motion analysis model in the single-wing ground condition of the aircraft and obtaining the expression of the rotation angle of the wing according to the aircraft motion analysis model comprises:

[0011] When an airplane makes an emergency landing with only one main landing gear deployed, the single wing tilts to one side. Assuming that the lift L of the single wing is constant and vertical to the wing, the expression of the lift L is: , wherein ρ is the air density, V is the airplane sliding speed, S is the projection area of the whole wing, and C L is the lift coefficient;

[0012] Assuming that the lift L and the gravity mg are both applied to the center of gravity C of the airplane, the airplane rotates around the main landing gear contact point A before the wing contacts the ground. The rotation process is similar to a single pendulum system. The rotation torque M of the airplane around the point A is:

[0013] , wherein m is the airplane mass, g is the gravity acceleration, s is the distance from the main landing gear tire contact point A to the gravity line, and a is the distance from the center of gravity C to the main landing gear axis;

[0014] Supposing that the distance b between the center of gravity C and the main landing gear tire contact point A is constant and unchangeable, the projection area S of the wing is related to the rotation angle θ, and the expression of the projection area S is:

[0015] ;

[0016] According to the lift expression, the rotation torque expression and the wing projection area expression, the rotation torque M is a function of the rotation angle θ, and the expression is as follows:

[0017] ;

[0018] According to Newton's second law: ;

[0019] , wherein is the rotation angle acceleration, I A is the rotation inertia of the airplane around the main landing gear tire contact point A, and the expression is as follows: (6), I C is the rotation inertia of the airplane around the center of gravity C;

[0020] The expression of the rotation angular velocity ω is obtained by integrating the Newton's second law formula once with respect to the rotation angle acceleration : ;

[0021] The rotation torque expression and the rotation inertia expression of the airplane around the main landing gear tire contact point A are substituted into the rotation angular velocity expression to obtain the expression of the rotation angular velocity when the wing contacts the ground:

[0022] ;

[0023] , wherein​ The initial value of the rotation angle is determined.

[0024] Preferably, the assumption condition is that during the process of the single-side wing of the airplane touching the ground, the change of the gravitational potential energy of the airplane, the work done by the lift, the energy loss of the propeller touching the ground and other energy conversion are ignored, and it is assumed that the rotational kinetic energy is converted into the bending strain energy of the wing.

[0025] Preferably, the process of establishing the expression for calculating the wingtip load after the wing touches the ground based on the assumption condition is as follows:

[0026] Taking the vertical median plane of the fuselage as the coordinate plane, the coordinate origin is located at the tire contact point A of the single-side main landing gear, the X-axis points to the wing span direction, and the Y-axis is vertically upward;

[0027] According to the layout of the airplane, the coordinates of the tire contact point A of the main landing gear and the wing tip D in the parked state are as follows:

[0028] 1) The coordinates of point A are (0, 0);

[0029] 2) The coordinates of point D are (x D ,y D );

[0030] According to the coordinate conversion relationship, the coordinates of the wingtip contact point D' are calculated from the coordinates of the wing tip D:

[0031] ;

[0032] Therefore, the Y-axis coordinate of the wingtip contact point D' is: ;

[0033] Since the Y-axis coordinate of the wingtip contact point D' when touching the ground is equal to the Y-axis coordinate of point A, there is:

[0034] ;

[0035] Therefore, the expression for the rotation angle θ1 of the wing when touching the ground is: ;

[0036] When the single-side wing is simplified as a cantilever beam, the wing span bending moment M(x) caused by the ground reaction force F of the wing is: , wherein: l is the half-span length of the wing; and x is the wing span coordinate.

[0037] Under the action of the wing span bending moment M(x), the strain energy ΔV of the single-side wing is: , wherein: (EI)(x) is the vertical bending stiffness curve of the wing along the span.

[0038] Let the change in rotational kinetic energy be equal to the bending strain energy, and we have: ;

[0039] The change of rotational kinetic energy and the strain energy expression of the single wing are substituted into to obtain:

[0040] ;

[0041] The wing spanwise bending moment expression is substituted into the above equation to obtain the expression of the ground reaction force F on the wing:

[0042] .

[0043] Preferably, the parameters required for the single wing ground contact load calculation include:

[0044] the lift coefficient C L ;

[0045] the moment of inertia I of the aircraft around the center of gravity C C ;

[0046] the projected area S of the wing;

[0047] the aircraft taxi speed V;

[0048] the distance a from the center of gravity C to the main landing gear axis;

[0049] the distance b between the center of gravity C and the main landing gear tire contact point A;

[0050] the wing half-span length l;

[0051] the aircraft mass m;

[0052] the initial rotation angle θ 0；

[0053] the initial rotation angular velocity ;

[0054] the air flow density ρ;

[0055] the coordinates (x D , y D ) of the wing tip D.

[0056] Preferably, based on the numerical values of the parameters and the expressions of the rotation angular velocity, the rotation angle expression when the wing contacts the ground, and the ground reaction force expression on the wing, the process of calculating the ground reaction force on the wing when the single wing contacts the ground is as follows:

[0057] According to the numerical values of the coordinates (x D , y D ) of the wing tip D, the rotation angle θ1 when the wing contacts the ground is first calculated according to the rotation angle expression when the wing contacts the ground;

[0058] Then, consider the following parameters: the wing's rotation angle θ1 upon touchdown, the aircraft's mass m, the distance b between the center of gravity C and the main landing gear tire contact point A, the distance a from the center of gravity C to the main landing gear axis, the airflow density ρ, the aircraft's taxiing speed V, the wing's projected area S, and the lift coefficient C. L The moment of inertia of the aircraft about its center of gravity C is I C Substituting the numerical values ​​into the expression for the angular velocity of rotation at wing touchdown, the angular velocity of rotation at wing touchdown is calculated. ;

[0059] Finally, the rotational angular velocity of the wing upon touchdown. and the moment of inertia I of the aircraft about its center of gravity C. C The values ​​of aircraft mass m, distance b between center of gravity C and main landing gear tire contact point A, wing half-span l, and vertical bending stiffness curve of a single wing are substituted into the wing support reaction force expression to calculate the ground-to-wing support reaction force F.

[0060] On the other hand, the technical solution provided in this application is: a device for calculating the ground contact load of a single-wing aircraft, comprising:

[0061] The analysis module is used to establish an aircraft motion analysis model when one wing of the aircraft touches the ground, and to obtain the expression for the rotational angular velocity when the wing touches the ground based on the aircraft motion analysis model.

[0062] The support reaction force construction module is used to construct the assumptions and establish the wingtip load calculation process after the wing touches the ground based on the assumptions, so as to obtain the expression of the rotation angle when the wing touches the ground and the expression of the ground support reaction force on the wing.

[0063] The parameter acquisition module is used to determine the parameters required for calculating the ground contact load of a single wing and to acquire the values ​​of the parameters.

[0064] The support reaction force calculation module is used to calculate the support reaction force of the ground on the wing when one wing touches the ground, based on the values ​​of the parameters, the expression of the angular velocity of the wing when it touches the ground, the expression of the rotation angle of the wing when it touches the ground, and the expression of the support reaction force of the ground on the wing.

[0065] Preferably, the analysis module establishes an aircraft motion analysis model when one wing of the aircraft touches the ground, and the process of obtaining the expression for the wing rotation angle based on the aircraft motion analysis model includes:

[0066] When an aircraft makes an emergency landing with only one main landing gear deployed, the wing tilts to one side. Assuming the lift L remains constant in magnitude and direction perpendicular to the wing upwards before the wing touches the ground, the expression for the lift L is: In the formula: ρ is the airflow density, V is the aircraft taxiing speed, S is the projected area of ​​the entire wing, and C... L The lift coefficient;

[0067] Assuming that the lift L and the gravity mg act on the center of gravity C of the aircraft, the aircraft rotates around the main landing gear contact point A before the wing contacts the ground, and the rotation process is similar to a single pendulum system. The rotation moment M of the aircraft around the point A is:

[0068] , wherein m is the mass of the aircraft, g is the acceleration of gravity, s is the distance from the main landing gear tire contact point A to the gravity line, and a is the distance from the center of gravity C to the main landing gear axis.

[0069] Suppose that the distance b between the center of gravity C and the main landing gear tire contact point A is a constant value and does not change during the rotation process. The projected area S of the wing is related to the rotation angle θ, and its expression is:

[0070] ;

[0071] According to the lift expression, the rotation moment expression, and the wing projected area expression, the rotation moment M is a function of the rotation angle θ, and the expression is as follows:

[0072] ;

[0073] According to Newton's second law: ;

[0074] , wherein is the rotation angle acceleration, I A is the moment of inertia of the aircraft around the main landing gear tire contact point A, and its expression is as follows: (6), I C is the moment of inertia of the aircraft around the center of gravity C.

[0075] Integrating the Newton's second law formula once on both sides with respect to the rotation angle acceleration , the expression of the rotation angle velocity is obtained: ;

[0076] Substituting the rotation moment expression and the moment of inertia expression of the aircraft around the main landing gear tire contact point A into the rotation angle velocity expression, the expression of the rotation angle velocity when the wing contacts the ground is obtained:

[0077] ;

[0078] , wherein is the initial value of the rotation angle velocity.

[0079] Preferably, the assumption condition is that during the process of the single wing of the aircraft contacting the ground, the change of the gravitational potential energy of the aircraft, the work done by the lift, the energy loss of the propeller contacting the ground, and other energy conversions are ignored. It is assumed that the rotation kinetic energy is converted into the wing bending strain energy.

[0080] Preferably, the wing-ground contact state establishing module establishes the process of building the wing tip load calculation expression after the wing touches the ground based on the assumption condition as follows:

[0081] Taking the vertical middle plane of the fuselage as the coordinate plane, the coordinate origin is located at the tire contact point A of the single-side main landing gear, the X axis points to the wing span direction, and the Y axis is vertically upward;

[0082] According to the aircraft layout, the coordinates of the tire contact point A of the main landing gear and the wing tip D in the parking state are as follows:

[0083] 1) A point coordinate (0, 0);

[0084] 2) D point coordinate (x D ,y D );

[0085] According to the coordinate conversion relationship, the coordinate of the wing tip contact point D' is calculated from the coordinate of the wing tip D:

[0086] ;

[0087] Therefore, the Y axis coordinate of the wing tip contact point D' is: ;

[0088] Since the Y axis coordinate of the wing tip contact point D' when touching the ground is equal to the Y axis coordinate of the point A, there is:

[0089] ;

[0090] Therefore, the expression of the rotation angle θ1 of the wing when touching the ground is: ;

[0091] Simplifying the single-side wing into a cantilever beam, the wing spanwise bending moment M(x) caused by the wing ground reaction force F is: , wherein: l is the half-span length of the wing; x is the wing spanwise coordinate;

[0092] Under the action of the wing spanwise bending moment M(x), the strain energy ΔV of the single-side wing is: , wherein: (EI)(x) is the vertical bending stiffness curve of the wing along the span;

[0093] Let the change of the rotational kinetic energy be equal to the bending strain energy, and the following is obtained: ;

[0094] Substituting the change of the rotational kinetic energy and the strain energy expression of the single-side wing into , the following is obtained:

[0095] ;

[0096] The expression of the wing spanwise bending moment is substituted into the above equation to obtain the expression of the ground reaction force F on the wing:

[0097] .

[0098] Preferably, the parameters required for the unilateral wing ground contact load calculation include:

[0099] the lift coefficient C L ;

[0100] the moment of inertia I of the aircraft around the center of gravity C C ;

[0101] the projected area S of the wing;

[0102] the aircraft taxi speed V;

[0103] the distance a from the center of gravity C to the main landing gear axis;

[0104] the distance b between the center of gravity C and the main landing gear tire contact point A;

[0105] the wing half-span length l;

[0106] the mass m of the aircraft;

[0107] the initial rotation angle θ 0；

[0108] the initial rotation angular velocity ω ;

[0109] the air flow density ρ;

[0110] the coordinates (x D , y D ) of the wing tip D.

[0111] Preferably, the process of calculating the ground reaction force on the wing when the unilateral wing is in contact with the ground based on the values of the parameters and the expression of the rotation angular velocity, the expression of the rotation angle when the wing is in contact with the ground, and the expression of the ground reaction force on the wing when the wing is in contact with the ground is as follows:

[0112] According to the values of the coordinates (x D , y D ) of the wing tip D, the rotation angle θ1 when the wing is in contact with the ground is first calculated according to the expression of the rotation angle when the wing is in contact with the ground;

[0113] Then, the rotation angle θ1 when the wing is in contact with the ground, the mass m of the aircraft, the distance b between the center of gravity C and the main landing gear tire contact point A, the distance a from the center of gravity C to the main landing gear axis, the air flow density ρ, the aircraft taxi speed V, the projected area S of the wing, the lift coefficient C L , and the moment of inertia I of the aircraft around the center of gravity C CSubstituting the numerical values ​​into the expression for the angular velocity of rotation at wing touchdown, the angular velocity of rotation at wing touchdown is calculated. ;

[0114] Finally, the rotational angular velocity when the wing touches the ground... and the moment of inertia I of the aircraft about its center of gravity C. C The values ​​of aircraft mass m, distance b between center of gravity C and main landing gear tire contact point A, wing half-span l, and vertical bending stiffness curve of a single wing are substituted into the wing support reaction force expression to calculate the ground-to-wing support reaction force F.

[0115] Thirdly, this application provides an electronic device, comprising:

[0116] One or more processors;

[0117] Memory;

[0118] One or more applications, which are stored in the memory and configured to be executed by the one or more processors, are configured to perform the calculation of the single-wing ground contact load of an aircraft as described in any of the preceding claims.

[0119] Fourthly, this application provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by a processor to realize the calculation of the ground contact load of a single wing of an aircraft as described in any of the preceding claims.

[0120] The method and apparatus of this application can reasonably and effectively determine the ground support reaction force on the wing when a single wing touches the ground, which has important guiding significance for the strength design of the wing structure. Compared with multibody dynamics modeling and simulation analysis, the implementation process of this application is simpler and more efficient. Attached Figure Description

[0121] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0122] Figure 1 This is a schematic diagram of the method for calculating the ground contact load of a single-wing aircraft according to this application.

[0123] Figure 2 This is a force analysis diagram of the wing before it touches the ground, as per this application.

[0124] Figure 3 This is a schematic diagram of the wing's ground contact process in this application.

[0125] Figure 4 Aircraft rotation diagram for the present application.

[0126] Figure 5 Single wing vertical bending stiffness curve for the present application.

[0127] Figure 6 Ground reaction force on the wing as a function of initial rotation angle velocity for the present application.

[0128] Figure 7 Aircraft single wing ground contact load calculation device diagram for the present application. DETAILED DESCRIPTION

[0129] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application embodiment will be described in more detail below in combination with the drawings of the present application embodiment.

[0130] In order to improve the calculation accuracy and efficiency of the ground load on the wing under the condition that the single wing is in contact with the ground when the aircraft lands in an emergency with only one side of the main landing gear deployed, the present application provides an aircraft single wing ground contact load calculation method and device.

[0131] As shown in Figure 1 , the present application first provides an aircraft single wing ground contact load calculation method, which comprises:

[0132] Step S1: Establish an aircraft motion analysis model under the condition that the single wing of the aircraft is in contact with the ground, and obtain an expression of the rotation angle velocity of the wing according to the aircraft motion analysis model.

[0133] As shown in Figure 2 , when the aircraft lands in an emergency with only one side of the main landing gear deployed, the single wing tilts to one side. Assuming that the lift L is constant and the direction is perpendicular to the wing upwards before the single wing touches the ground, the expression of the lift L at this time is: ; (1)

[0134] In the formula: p is the air density, V is the aircraft sliding speed, S is the projected area of the entire wing, C L is the lift coefficient.

[0135] Assuming that the lift L and the gravity mg both act on the center of gravity C of the aircraft, the aircraft rotates around the main landing gear contact point A before the wing touches the ground, and the rotation process is similar to a pendulum system. The rotation moment M of the aircraft around point A is:

[0136] ; (2)

[0137] In the formula: m is the mass of the aircraft, g is the acceleration of gravity (usually taken as 9.8 m / s 2), s is the distance from the main landing gear tire contact point A to the line of gravity, and a is the distance from the center of gravity C to the main landing gear axis.

[0138] Assume that the distance b between the center of gravity C and the contact point A of the main landing gear tires is a constant during rotation, and the projected area S of the wing is related to the rotation angle θ, with the following expression:

[0139] (3)

[0140] From equations (1) to (3), it can be seen that the rotational torque M is a function of the rotation angle θ, and the expression is as follows:

[0141] (4)

[0142] According to Newton's second law: (5)

[0143] In the formula: Let I be the rotational angular acceleration. A Let A be the moment of inertia of the aircraft about the contact point A of the main landing gear tires, and its expression is as follows: (6)

[0144] In the formula: I C Let C be the moment of inertia of the aircraft about its center of gravity, point C.

[0145] Applying equation (5) to the rotational angular acceleration The rotational angular velocity can be obtained by performing one integration. The expression:

[0146] (7)

[0147] Substituting equations (4) and (6) into equation (7) and rearranging, we get:

[0148] (8)

[0149] In the formula: This is the initial value of the rotational angular velocity.

[0150] From equation (8), it can be seen that the rotational angular velocity during the rotation process is With rotation angle One-to-one correspondence, if the rotation angle is known. Then the rotational angular velocity can be obtained. .

[0151] Step S2: Construct the assumptions and establish the calculation expression for the wingtip load after the wing touches the ground based on the assumptions.

[0152] like Figure 3As shown, during the single-wing contact process of an aircraft, the changes in the aircraft's gravitational potential energy, lift work, propeller contact energy loss, and the conversion of other energy sources (landing gear energy absorption, frictional energy loss, etc.) are neglected. It is assumed that rotational kinetic energy is converted into wing bending strain energy. Theoretically, the wingtip load obtained based on this assumption is conservative.

[0153] At the moment when the rotational angular velocity is zero, all the rotational kinetic energy of the fuselage is converted into the bending strain energy of the wing, at which point the ground load reaches its maximum. During this process, the change in rotational kinetic energy ΔE is: (9)

[0154] In the formula: ω is the rotational angular velocity at the moment of contact with the ground.

[0155] From equation (8), it can be seen that if we want to solve for the rotational angular velocity at the moment of contact with the ground... Then, the rotation angle θ1 at the moment of contact with the ground needs to be known. According to Figure 4 The rotational geometry of the aircraft shown can be calculated by the rotation angle θ1 when the wings touch the ground. The solid line in the figure is a schematic diagram when the aircraft is horizontal, and the dashed line is a schematic diagram when the rotation angle θ1 is 1.

[0156] The specific calculation method for the rotation angle θ1 when the wing touches the ground is as follows:

[0157] Using the fuselage's vertical mid-plane as the coordinate plane, with the origin at the tire contact point A of the main landing gear on one side, the X-axis points towards the wing span, and the Y-axis points vertically upward. Based on the aircraft layout, the coordinates (in meters) of the main landing gear tire contact point A and the wingtip D in the parked state are as follows:

[0158] 1) The coordinates of point A are (0,0);

[0159] 2) Coordinates of point D (x D ,y D ).

[0160] The coordinates of the wingtip contact point D' can be calculated using the coordinate transformation relationship based on the coordinates of point D at the wingtip:

[0161] (10)

[0162] Therefore, the Y-axis coordinate of the wingtip contact point D' is: (11)

[0163] Since the Y-coordinate of the wingtip contact point D' at touchdown is equal to the Y-coordinate of point A, therefore:

[0164] (12)

[0165] Therefore, the expression for the rotation angle θ1 when the wing touches the ground can be obtained as follows: ; (13)

[0166] The wing is simplified as a cantilever beam, and the wing spanwise bending moment M(x) caused by the ground reaction force F is: ; (14)

[0167] In the formula, l is the wing half-span length, and x is the wing spanwise position coordinate.

[0168] Under the action of the wing spanwise bending moment M(x), the strain energy AV of the single-side wing is:

[0169] ; (15)

[0170] In the formula, (EI)(x) is the vertical bending stiffness curve of the wing along the span.

[0171] Let the change in rotational kinetic energy be equal to the bending strain energy, and the following is obtained: ; (16)

[0172] Substituting formula (9) and formula (15) into formula (16) can obtain: ; (17)

[0173] Substituting formula (14) into formula (17) can obtain the expression of the ground reaction force F on the wing:

[0174] (18)

[0175] Step S3: Determine the parameters required for calculating the single-side wing touch load, and obtain the numerical values of the parameters.

[0176] According to the theoretical calculation formula established in steps S1 and S2, if the single-side wing touch load is to be calculated, 13 parameters shown in Table 1 and their numerical values and the single-side wing vertical bending stiffness curve are required. In the remarks column of Table 1, the acquisition method of each parameter is explained. The numerical value of the single-side wing vertical bending stiffness curve can be obtained from the aircraft wing stiffness calculation report.

[0177] Table 1 Parameters required for calculating the single-side wing touch load

[0178] Serial number Parameter symbol Dimension Remark 1 [C L ]]> / Obtained from the aircraft lift curve 2 I C ]]> [kg·m 2 ]]> Obtained from the aircraft moment of inertia calculation result 3 S m 2 ]]> Obtained from the aircraft overall layout parameters 4 V m / s Obtained from the aircraft flight performance parameters 5 a m Obtained from the aircraft overall layout parameters 6 b m Obtained from the aircraft overall layout parameters 7 l m Obtained from the aircraft overall layout parameters 8 m kg Obtained from the aircraft weight calculation result 9 [theta0] rad Obtained from the aircraft flight performance parameters 10 rad / s Obtained from the aircraft flight performance parameters 11 ρ kg / m 3 ]]> Can be converted according to the sea level height of the landing site of the aircraft 12 x D ]]> m Obtained from the aircraft overall layout parameters 13 y D ]]> m Obtained from the aircraft overall layout parameters

[0179] Step S4: The numerical values of the required parameters are brought into the expression of the rotational angular velocity when the wing touches the ground, the expression of the rotational angle when the wing touches the ground, and the expression of the ground reaction force on the wing, so as to calculate the ground reaction force on the wing when the single-side wing touches the ground.

[0180] The parameters x D , y DThe value is obtained by first calculating the rotation angle θ1 when the wing touches the ground according to equation (13), and then substituting the rotation angle θ1 and the relevant parameter values ​​in Table 1 into equation (8) to calculate the angular velocity of the wing when it touches the ground. Finally, the angular velocity of the wing when it touches the ground The ground reaction force F on the wing is calculated by substituting the values ​​of the relevant parameters in Table 1 and the vertical bending stiffness curve of the wing on one side into equation (18).

[0181] The present application will be further described below with reference to specific embodiments provided in the present application. The derivation process of the formulas for steps S1 and S2 in the method of the present application will not be repeated.

[0182] Table 2 shows the values ​​of the parameters required for calculating the ground contact load of a single wing in this embodiment of the present application. Figure 5 The figure shows the vertical bending stiffness curve of a single wing in this embodiment of the present application. The corresponding values ​​of the curve are shown in Table 3.

[0183] Table 2. Parameter values ​​required for calculating the ground contact load of a single wing.

[0184] Serial number Parameter symbol Dimension Parameter value 1 C L ]]> / 2.28 2 I C ]]> [kg·m 2 ]]> 373186 3 S m 2 ]]> 65 4 V m / s 48.17 5 a m 2.090 6 b m 3.721 7 l m 13.966 8 m kg 27800 9 [theta0] rad 0 10 rad / s 0 11 ρ kg / m 3 ]]> 1.225 12 x D ]]> m 16.056 13 [[ y D ]]> m 3.705

[0185] Table 3 Numerical values ​​of bending stiffness curves for a single wing

[0186] Spanwise coordinate / m Bending stiffness / (N-m 2 ) Spanwise coordinate / m Bending stiffness / (N-m 2 ) Spanwise coordinate / m Bending stiffness / (N-m 2 ) 0 1.33 x 10 8 ]]> 4.75 5.21 x 10 7 ]]> 9.65 8.15 x 10 6 ]]> 0.62 1.23 x 10 8 ]] 5.24 4.49 x 10 7 ]]> 10.14 6.51 x 10 6 ]]> 1.15 1.11 x 10 8 ]]> 5.73 3.63 x 10 7 ]]> 10.63 4.90 x 10 6 ]] 1.73 9.92 x 10 7 ]] 6.22 3.11 x 10 7 ]] 11.15 3.50 x 10 6 ]]> 2.18 9.01 x 10 7 ]] 6.71 2.57 x 10 7 ]] 11.66 2.49 x 10 6 ]] 2.63 8.27 x 10 7 ]]> 7.20 2.09 x 10 7 ]]> 12.17 1.96 x 10 6 ]]> 3.08 7.68 x 10 7 ]] 7.69 1.71 x 10 7 ]]> 12.69 1.54 x 10 6 ]]> 3.53 7.13 x 10 7 ]]> 8.18 1.40 x 10 7 ]]> 13.20 1.23 x 10 6 ]]> 4.01 6.51 x 10 7 ]]> 8.67 1.17 x 10 7 ]]> 13.966 1.0 4.38 5.77 x 10 7 ]]> 9.16 9.80 x 10 6 ]]>

[0187] First, based on the coordinate values ​​xD and yD of the wingtip D in Table 2, the rotation angle of the wing when it touches the ground is calculated according to equation (13): ;

[0188] Then, the calculated rotation angle θ1 at wing touchdown and the relevant parameter values ​​in Table 2 are substituted into equation (8) to calculate the angular velocity of the wing at wing touchdown:

[0189]

[0190] Finally, the rotational angular velocity of the wing upon touchdown. Substituting the relevant parameter values ​​in Table 2 and the bending stiffness curve values ​​of a single wing into equation (18), the ground reaction force F on the wing when a single wing touches the ground is calculated:

[0191] .

[0192] In this embodiment of the application, different initial values ​​of rotational angular velocity are also provided. Calculate the corresponding ground reaction force F on the wing, and analyze the ground reaction force F on the wing as a function of the initial value of the rotational angular velocity. The changing pattern.

[0193] For example, in this embodiment of the present application, the initial value of the rotation angular velocity is set to be 0.10 rad / s, 0.15 rad / s, 0.20 rad / s, 0.25 rad / s, 0.30 rad / s respectively, and the rest of the parameters remain unchanged, the corresponding ground-to-wing support reaction force F is calculated, and the calculation results are shown in Table 4. Figure 6 The curve of the ground-to-wing support reaction force F with the initial value of the rotation angular velocity is shown. It can be seen that the ground-to-wing support reaction force linearly increases with the increase of the initial value of the rotation angular velocity, which conforms to the general law, and the support reaction force value conforms to the actual situation, indicating that the method has certain rationality.

[0194] Table 4 Ground-to-wing support reaction force corresponding to different initial values of rotation angular velocity

[0195] Initial value of rotation angular velocity / (rad / s) 0.10 0.15 0.20 0.25 0.30 Ground-to-airfoil support reaction force / N 29017 37844 46671 55497 64324

[0196] The method of the present application can reasonably and effectively determine the ground support reaction force on the wing when the single-sided wing touches the ground, which has important guiding significance for the strength design of the wing structure. Compared with the multi-body dynamics modeling and simulation analysis means, the implementation process of the present application is simple and efficient.

[0197] As shown in Figure 7 , on this basis, the present application further provides an aircraft single-sided wing ground contact load calculation device, the device 100 comprises:

[0198] An analysis module 101 is configured to establish an aircraft motion analysis model in the single-sided wing ground contact condition of an aircraft, and obtain an expression of the rotation angular velocity when the wing touches the ground according to the aircraft motion analysis model;

[0199] A support reaction force construction module 102 is configured to construct a hypothetical condition, establish a wing tip load calculation process after the wing touches the ground based on the hypothetical condition, and obtain an expression of the rotation angle and an expression of the ground-to-wing support reaction force when the wing touches the ground;

[0200] A parameter acquisition module 103 is configured to determine parameters required for single-sided wing ground contact load calculation, and acquire numerical values of the parameters;

[0201] A support reaction force calculation module 104 is configured to calculate the ground-to-wing support reaction force when the single-sided wing touches the ground based on the numerical values of the parameters and the expression of the rotation angular velocity when the wing touches the ground, the expression of the rotation angle when the wing touches the ground, and the expression of the ground-to-wing support reaction force.

[0202] The processing process of each module of the aircraft single-sided wing ground contact load calculation device of the present application can refer to the aircraft single-sided wing ground contact load calculation method described above, and will not be described here.

[0203] In addition, the application further provides an electronic device, comprising: one or more processors; a memory; one or more application programs stored in the memory and configured to be executed by the one or more processors, the one or more application programs being configured to implement the aircraft single-side wing touch-down load calculation method according to any one of the above.

[0204] Finally, the application further provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores at least one instruction, at least one program, a code set or an instruction set, which are loaded and executed by a processor to implement the aircraft single-side wing touch-down load calculation method according to any one of the above.

[0205] The above is only a specific implementation of the application, but the protection scope of the application is not limited thereto, and any changes or replacements easily thought of by those skilled in the art within the technical range disclosed by the application should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A method for calculating a single-side wing touch-down load of an aircraft, characterized by, The application relates to a method for calculating the ground reaction force of a single wing of an airplane when the wing touches the ground. The method comprises the following steps: establishing an airplane motion analysis model when the single wing of the airplane touches the ground, and obtaining an expression of a rotation angle of the wing according to the airplane motion analysis model; constructing a hypothesis condition, establishing a wing tip load calculation process after the wing touches the ground based on the hypothesis condition, and obtaining an expression of the rotation angle of the wing when the wing touches the ground and an expression of a ground reaction force of the wing; determining parameters required for the single wing touch ground load calculation, and obtaining numerical values of the parameters; 2. The method of claim 1, wherein, calculating the ground reaction force of the wing when the single wing touches the ground based on the numerical values of the parameters and the expression of the rotation angle of the wing when the wing touches the ground and the expression of the ground reaction force of the wing. When the airplane makes an emergency landing with only one main landing gear deployed, the single wing tilts to one side. Assuming that the lift L of the single wing is constant and vertical to the wing, the expression of the lift L is: , where: p is the air density, V is the airplane sliding speed, S is the projected area of the whole wing, and C L is the lift coefficient. The process of establishing an airplane motion analysis model when the single wing of the airplane touches the ground and obtaining an expression of a rotation angle of the wing according to the airplane motion analysis model comprises the following steps: where m is the mass of the aircraft, g is the acceleration due to gravity, s is the distance from the main landing gear tire contact patch A to the line of action of gravity, and a is the distance from the center of gravity C to the main landing gear axis. assuming that lift L and gravity mg are applied to a gravity center C of the airplane, the airplane rotates around a main landing gear touch point A before the wing touches the ground, the rotation process is similar to a single pendulum system, a rotation torque M of the airplane around the point A is: ； assuming that a distance b between the gravity center C and the main landing gear tire touch point A is a constant value and does not change, a projection area S of the wing is related to a rotation angle theta theta, and an expression of the projection area S is: ； According to Newton's second law: ; wherein: is the angular acceleration of rotation, I A is the moment of inertia of the aircraft about the main landing gear tire contact point A, which is expressed as follows: (6), I C is the moment of inertia of the aircraft about the center of gravity C. Divide both sides of the equation of Newton's second law by the moment of inertia to obtain the expression for angular velocity after integrating once: ; according to the expression of the lift, the expression of the rotation torque and the expression of the projection area of the wing, the rotation torque M is a function of the rotation angle theta, and the expression is as follows: ； In the formula: is the initial value of the angular velocity of rotation.

3. The method of claim 2, wherein, the expression of the rotation torque is substituted into the expression of the rotation angle velocity to obtain an expression of the rotation angle velocity of the wing when the wing touches the ground:

4. The method of claim 3, wherein, the hypothesis condition is that, during the single wing touch ground process of the airplane, the change of the gravitational potential energy of the airplane, the work done by the lift, the energy loss of the propeller when touching the ground and the conversion of other energies are ignored, and it is assumed that the rotation kinetic energy is converted into the wing bending strain energy. The process of establishing a wing tip load calculation expression of the wing after the wing touches the ground based on the hypothesis condition comprises the following steps: taking a vertical center plane of the fuselage as a coordinate plane, a coordinate origin is located at a single main landing gear tire touch point A, an X-axis points to a wing span direction, and a Y-axis is vertically upward; according to the airplane layout, coordinates of the main landing gear tire touch point A and a wing tip D in a parked state are obtained as follows: 2) D point coordinates (x D ,y D ); 1) the point A coordinate (0, 0); ； Thus, the Y-axis coordinate of the wingtip touch-down point D' is: ; the wing tip touch point D' coordinate is calculated according to the wing tip D point coordinate by a coordinate conversion relationship: ； Therefore, the expression of the rotation angle θ1 of the wing at the time of touching the ground is ; If the single wing is simplified as a cantilever beam, the wing spanwise bending moment M(x) caused by the ground reaction force F is: , where: l is the wing half-span; x is the wing spanwise position coordinate; The strain energy AV of the single-sided wing under the action of the wing spanwise bending moment M(x) is: where (EI)(x) is the vertical bending stiffness curve of the wing along the span direction. Let the change of rotational kinetic energy equal to the bending strain energy, get: ; The amount of change in rotational kinetic energy and the strain energy expression of the single side wing are substituted into The following is obtained: ； since the Y-axis coordinate of the wing tip touch point D' when touching the ground is equal to the Y-axis coordinate of the point A, the following equation is obtained: 。 5. The method of claim 4, wherein, the expression of the wing span bending moment is substituted into the above equation to obtain an expression of a ground reaction force F of the wing: Lift coefficient C L ; The moment of inertia I of the aircraft about the center of gravity C C ; the parameters required for the single wing touch ground load calculation comprise: a projection area S of the wing; an airplane sliding speed V; a distance a from the gravity center C to a main landing gear axis; a distance b between the gravity center C and the main landing gear tire touch point A; a wing half span length l; Rotation angle initial value θ 0； initial value of rotational angular velocity ; an airplane mass m; Coordinates (x D , y D ) of wing tip D.

6. The method of claim 5, wherein, an air flow density p; According to the values of the coordinates (x D , y D ) of the wing tip D, the rotation angle θ1 when the wing touches the ground is first calculated from the rotation angle expression when the wing touches the ground; Then the values of the turning angle θ1 at the time of the wing touching the ground, the mass m of the aircraft, the distance b between the center of gravity point C and the tire contact point A of the main landing gear, the distance a from the center of gravity point C to the main landing gear axis, the air density ρ, the aircraft sliding speed V, the projected area S of the wing, the lift coefficient C L , the moment of inertia I of the aircraft around the center of gravity point C C are substituted into the expression for the turning angular speed at the time of the wing touching the ground to calculate the turning angular speed at the time of the wing touching the ground ; the angular velocity of the wing at the moment of touching the ground and the moment of inertia I of the airplane around the center of gravity C C the values of the airplane mass m, the distance b between the center of gravity C and the point A where the tire of the main landing gear touches the ground, the half-span of the wing l, and the curve of the vertical bending stiffness of the wing on one side are substituted into the expression of the wing support reaction force F to calculate the ground reaction force on the wing support.

7. An apparatus for calculating a single-side wing touch-down load of an aircraft, characterized by comprising: the process of calculating the ground reaction force of the wing when the single wing touches the ground based on the numerical values of the parameters and the expression of the rotation angle velocity, the expression of the rotation angle of the wing when the wing touches the ground and the expression of the ground reaction force of the wing comprises the following steps: The analysis module is configured to establish an aircraft motion analysis model in a single-wing-touching-ground condition of the aircraft, and to obtain an expression of a rotation angle velocity of the aircraft wing when the wing touches the ground according to the aircraft motion analysis model. The support reaction force construction module is configured to construct a hypothesis condition, to establish a wing tip load calculation process after the wing touches the ground based on the hypothesis condition, to obtain an expression of a rotation angle of the wing when the wing touches the ground, and to obtain an expression of a support reaction force of the wing by the ground when the wing touches the ground. The parameter acquisition module is configured to determine parameters required for single-wing-touching-ground load calculation, and to acquire numerical values of the parameters. The support reaction force calculation module is configured to calculate the support reaction force of the wing by the ground when the wing touches the ground based on the numerical values of the parameters and the expression of the rotation angle velocity of the wing when the wing touches the ground, the expression of the rotation angle of the wing when the wing touches the ground, and the expression of the support reaction force of the wing by the ground when the wing touches the ground.

8. The aircraft single-sided wing touch down load calculation device of claim 7, wherein, The analysis module establishes an aircraft motion analysis model in a single-wing-touching-ground condition of the aircraft, and the process of obtaining an expression of a rotation angle of the wing according to the aircraft motion analysis model includes: When the airplane makes an emergency landing with only one main landing gear deployed, the single wing tilts to one side. Assuming that the lift L of the single wing is constant and vertical to the wing, the expression of the lift L is: , where: p is the air density, V is the airplane sliding speed, S is the projected area of the whole wing, and C L is the lift coefficient. It is assumed that the lift L and the gravity mg are both applied to the center of gravity C of the aircraft, and the aircraft rotates around the main landing gear contact point A before the wing touches the ground, and the rotation process is similar to a simple pendulum system. The rotation torque M of the aircraft around the point A is: where m is the mass of the aircraft, g is the acceleration due to gravity, s is the distance from the main landing gear tire contact patch A to the line of action of gravity, and a is the distance from the center of gravity C to the main landing gear axis. It is assumed that the distance b between the center of gravity C and the main landing gear tire contact point A is a constant value and does not change. The projected area S of the wing is related to the rotation angle θ, and the expression is: ； According to the lift expression, the rotation torque expression and the wing projected area expression, the rotation torque M is a function of the rotation angle θ, and the expression is as follows: ； According to Newton's second law: ; wherein: is the angular acceleration of rotation, I A is the moment of inertia of the aircraft about the main landing gear tire contact point A, which is expressed as follows: (6), I C is the moment of inertia of the aircraft about the center of gravity C. Divide both sides of the equation of Newton's second law by the moment of inertia Take the first integral to get the angular velocity of the expression: ; The rotation torque expression and the rotation inertia expression of the aircraft around the main landing gear tire contact point A are substituted into the rotation angle velocity expression to obtain the expression of the rotation angle velocity of the wing when the wing touches the ground: ； In the formula: is the initial value of the rotational angular velocity.

9. The aircraft single-sided wing touch down load calculation device of claim 8, wherein, The hypothesis condition is that, during the single-wing-touching-ground process of the aircraft, the change of the gravitational potential energy of the aircraft, the work done by the lift, the energy loss of the propeller when touching the ground and the conversion of other energies are ignored, and it is assumed that the rotational kinetic energy is converted into the wing bending strain energy.

10. The method of claim 9, wherein, The support reaction force construction module establishes the wing tip load calculation expression of the wing after touching the ground based on the hypothesis condition, and the process is: The vertical center plane of the fuselage is taken as a coordinate plane, and the coordinate origin is located at the single-main-landing-gear tire contact point A. The X-axis points to the wing span direction, and the Y-axis is vertically upward. According to the aircraft layout, the coordinates of the main landing gear tire contact point A and the wing tip D in the parked state are respectively: 1) The coordinates of the point A (0, 0); 2) D point coordinates (x D ,y D ); The coordinates of the wing tip contact point D' are calculated according to the coordinate conversion relationship of the wing tip D point coordinates: ； Thus, the Y-axis coordinate of the wing tip touch down point D' is: ; Since the Y-axis coordinate of the wing tip contact point D' when touching the ground is equal to the Y-axis coordinate of the point A, there is: ； Therefore, the expression of the rotation angle θ1 of the wing at the time of touching the ground is ; If the single wing is simplified as a cantilever beam, the wing spanwise bending moment M(x) caused by the ground reaction force F is: , where: l is the wing half-span; x is the wing spanwise position coordinate; The strain energy AV of the single-sided wing under the action of the wing spanwise bending moment M(x) is: where (EI)(x) is the vertical bending stiffness curve of the wing along the span direction. Let the change of rotational kinetic energy equal to the bending strain energy, get: ; The amount of change in rotational kinetic energy and the strain energy expression of the single side wing into The following is obtained: ； The wing span bending moment expression is substituted into the above formula to obtain the expression of the support reaction force F of the wing by the ground: 。 11. The aircraft single-sided wing touch down load calculation device of Claim 10, wherein, The parameters required for single-wing-touching-ground load calculation include: Lift coefficient C L ; The moment of inertia I of the aircraft about the center of gravity C C ; The projected area S of the wing; The aircraft sliding speed V; The distance a from the center of gravity C to the main landing gear axis; The distance b between the center of gravity C and the main landing gear tire contact point A; The wing half-span length l; The aircraft mass m; Rotation angle initial value θ 0； initial value of the rotational angular velocity ; The air density ρ; Coordinates (x D , y D ) of wing tip D.

12. The aircraft single-sided wing touch down load calculation device of Claim 11, wherein, The support reaction force calculation module calculates the support reaction force of the wing on the ground based on the numerical value of the parameter, the expression of the rotation angular velocity, the expression of the rotation angle when the wing touches the ground, and the expression of the support reaction force of the wing on the ground, and the process is as follows: According to the values of the coordinates (x D , y D ) of the wing tip D, the rotation angle θ1 when the wing touches the ground is first calculated from the rotation angle expression when the wing touches the ground; Then the values of the turning angle θ1 at the time of the wing touching the ground, the mass m of the aircraft, the distance b between the center of gravity point C and the tire contact point A of the main landing gear, the distance a from the center of gravity point C to the main landing gear axis, the air density ρ, the aircraft sliding speed V, the projected area S of the wing, the lift coefficient C L , the moment of inertia I of the aircraft around the center of gravity point C C of the aircraft are substituted into the expression for the turning angular speed at the time of the wing touching the ground to calculate the turning angular speed at the time of the wing touching the ground ; the angular velocity of the wing at the moment of touching the ground and the moment of inertia I of the airplane around the center of gravity C C the values of the airplane mass m, the distance b between the center of gravity C and the point A where the tire of the main landing gear touches the ground, the half-span of the wing l, and the curve of the vertical bending stiffness of the wing on one side are substituted into the expression of the wing support reaction force F to calculate the ground reaction force F on the wing support.

13. An electronic device, comprising: comprise: one or more processors; a memory; one or more application programs stored in the memory and configured to be executed by the one or more processors, the one or more application programs being configured to implement the aircraft single-wing ground contact load calculation according to any one of claims 1-6.

14. A computer-readable storage medium, characterized in that, The computer readable storage medium stores at least one instruction, at least one program, a code set or an instruction set, which is loaded and executed by the processor to implement the aircraft single-wing ground contact load calculation according to any one of claims 1-6.

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