A composite material integral longitudinal and transverse reinforced frame layup design method

Abstract

The present invention belongs to the technical field of composite material structure design, and specifically relates to a composite material integral longitudinal and transverse reinforced frame ply design method. The method systematically provides a composite material integral longitudinal and transverse reinforced frame ply design method, solves the ply design problem of which ribs should be continuous and which ribs should be disconnected in the longitudinal or transverse reinforcement, and improves the overall mechanical properties of the composite material integral longitudinal and transverse reinforced frame.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material structure design, and in particular relates to a composite material integral longitudinal and transverse reinforced frame ply design method. Background Art

[0002] In the composite cabin structure, the composite integral longitudinal and transverse reinforced frame is the main load-bearing frame, which has the structural characteristics of large size, complex shape, and multiple longitudinal or transverse reinforcements. Its manufacturing process adopts RTM integral molding process, with good process quality and mechanical properties, but in the layer design, it always faces the problem of continuous reinforcement on one side and disconnected reinforcement on the other side at the longitudinal or transverse cross reinforcement, which leads to poor mechanical properties of the integral frame in a certain direction.

[0003] Patent CN103341987A discloses a co-curing process for an integral wall panel of composite materials with longitudinal or transverse reinforcement of Ω long girders, wherein the longitudinal hat-shaped long girders are co-cured with the wall panels, and the transverse ribs are notched at the long girders and bonded to the wall panels for a secondary bonding. CN105216345A discloses an RTM integrally formed longitudinal or transversely reinforced structure cover and a manufacturing method thereof, wherein the longitudinal ribs are continuous and the transverse ribs are disconnected. The above two treatment methods reduce the transverse mechanical properties and are not suitable for the main load-bearing frame. CN210553131U discloses an integral curing molding mold for longitudinal or transversely reinforced wall panels of composite materials. The manufactured reinforced panels do not have longitudinal or transverse cross reinforcements, and therefore the ply design problem of cross reinforcements is not considered. In summary, the present invention discloses a ply design method for an integral longitudinal and transversely reinforced frame of composite materials, which improves the overall mechanical properties of the integral longitudinal and transversely reinforced frame of composite materials from the perspective of ply design. Summary of the invention

[0004] The purpose of the present invention is to provide a composite material integral longitudinal and transverse reinforced frame ply design method, which can be used for the structural design of composite material integral longitudinal or transverse reinforced main load-bearing frame.

[0005] The technical solution of the present invention is a composite material integral longitudinal and transverse reinforced frame ply design method, comprising the following steps:

[0006] Step 1: Determine the load conditions, longitudinal and transverse reinforcement layout, and dimensional parameters of the reinforced plate of the composite material integral longitudinal and transverse reinforced frame, and mark the frame edge, longitudinal ribs, transverse ribs, and the intersection of longitudinal and transverse ribs in the specified order;

[0007] Step 2: Conduct static analysis on the stress conditions of the composite material integral longitudinal and transverse reinforced frame under various load conditions to obtain the stress distribution of the longitudinal and transverse ribs on the composite material integral longitudinal and transverse reinforced frame under various load conditions;

[0008] Step 3: According to the stress distribution of the longitudinal and transverse ribs on the composite material integral longitudinal and transverse reinforcement frame under various load conditions, the maximum stress reduction coefficient method is used to extract and mark the important overall load stress area and the important local load stress area on the longitudinal and transverse ribs;

[0009] Step 4: Determine the longitudinal and transverse overall force transmission paths and the longitudinal and transverse local force transmission path positions according to the important overall load stress areas and important local load stress areas of the overall longitudinal and transverse reinforced frame of the composite material;

[0010] Step 5: According to the important local load stress area of ​​the overall longitudinal and transverse reinforced frame of the composite material, and the positions of the longitudinal and transverse local force transmission paths, respectively determine the continuous lengths of the longitudinal and transverse local force transmission paths; According to the important overall load stress area of ​​the overall longitudinal and transverse reinforced frame of the composite material, and the positions of the longitudinal and transverse overall force transmission paths, respectively determine the continuous lengths of the longitudinal and transverse overall force transmission paths;

[0011] Step 6: Design the ply according to the continuous length of each longitudinal and transverse overall main force transmission path and longitudinal and transverse local force transmission path.

[0012] In a possible embodiment, the load condition includes an overall load condition and a local load condition; the overall load includes but is not limited to longitudinal tension, transverse tension, longitudinal compression, transverse compression, longitudinal bending, transverse bending, in-plane shear, and out-of-plane pressure load; the overall load condition is a combination of one or more of the above-mentioned overall loads; the local load includes but is not limited to the equipment installation load installed on one or several ribs, the actuator load, and the hanging point load; the local load condition is a single combination of the above-mentioned local loads.

[0013] In a possible embodiment, the overall load condition may be one or more, and the local load condition may be none, one, or more.

[0014] In a possible embodiment, in step 1, the method for marking the frame edge, longitudinal ribs, transverse ribs, and the intersection of the longitudinal and transverse ribs of the composite material integral longitudinal and transverse reinforced frame is as follows:

[0015] Mark the outer edge strips and longitudinal or transverse ribs of the reinforced frame in the order from top to bottom and from left to right; among them, the transverse outer frame edge and transverse ribs are marked as H0, H1, H2, ... H in the order from top to bottom. m , ...H M+1 , where M is the number of transverse ribs, 1≤m≤M; H0 represents the uppermost outer frame edge, H N+1 Indicated as the bottom outer frame edge; H1, H2, ... H m , ...H MIndicates the 1st, 2nd, ..., m, ...Mth transverse ribs from top to bottom; similarly, from left to right, the longitudinal outer frame edges and longitudinal ribs are marked as Z0, Z1, Z2, ...Z n ,...Z N+1 , where N is the number of longitudinal ribs, 1≤n≤N; from top to bottom and from left to right, mark the intersection between the longitudinal and transverse ribs as A n,m , represents the intersection point between the nth longitudinal rib and the mth transverse rib; the marking method of the intersection points between the frame edges and the frame edges and the ribs is the same; from top to bottom and from left to right, mark the intersection point A n,m With A n,m+1 The ribs between are marked as Indicates the longitudinal rib Z n On the top, the rib segment is divided by the mth and m+1th transverse ribs; the intersection point A n,m With A n+1,m The ribs between are marked as Indicates the transverse rib H m The rib segments are divided by the nth and n+1th longitudinal ribs. According to the definition, the transverse rib H m Depend on Connected end to end, longitudinal ribs Z n Depend on Connected end to end.

[0016] In a possible embodiment, in step 2, finite element simulation analysis is used to perform finite element modeling on the composite material longitudinal and transverse reinforcement frame using shell units or solid units, and the grid size is determined according to the results of grid convergence analysis; the material of the composite material overall longitudinal and transverse reinforcement frame is simplified to an isotropic material, the load conditions are set to each load condition in turn, the boundary conditions are simplified according to the actual boundaries of the composite material overall longitudinal and transverse reinforcement frame, and the static linear analysis method is used to calculate the longitudinal and transverse rib von Mises stress distribution of the composite material overall longitudinal and transverse reinforcement frame under each load condition.

[0017] Preferably, the finite element unit type is a linear, finite membrane strain, reduced integral quadrilateral shell unit; the stress error threshold of the mesh convergence analysis is set to 5%; the material is set to aluminum alloy material; the frame edge boundary condition is set to simply supported; the static linear analysis method is the Full Newton algorithm; and the von Mises stress extracts the unique nodal stress.

[0018] In one possible embodiment, in step 3, the maximum stress reduction coefficient method is used to extract and mark the important overall load stress areas under all overall load conditions. The method is as follows: assuming that there are I overall load conditions, for any i-th overall load condition, where 1≤i≤I, the negative stress values ​​in the von Mises stress distribution of the longitudinal and transverse ribs are taken as absolute values, and any longitudinal rib Z is examined. n Any rib segment on The maximum stress value under this overall load condition is recorded as The maximum stress value of the rib segment under I overall load conditions is set as a set, and the maximum value of the set is defined as Right now Similarly, any transverse rib H m Any rib segment on The maximum stress value under all overall load conditions is The maximum stress values ​​s of all longitudinal and transverse rib segments under all overall load conditions are calculated in descending order. max Arrange, get The value 2MN+M+N represents the number of all rib segments contained in N longitudinal ribs and M transverse ribs; the maximum stress reduction factor η is defined, where 0≤η≤1, if Where 1≤x≤2MN+M+N, then The small segment of the rib is defined as an important overall load stress area; preferably, the maximum stress reduction factor η is taken as 0.8.

[0019] In one possible embodiment, the maximum stress reduction coefficient method is used to extract and mark the important local load stress areas under all local load conditions. The method is as follows: assuming that there are J local load conditions in total, for any j-th local load condition, where 1≤j≤J, the negative stress values ​​in the von Mises stress distribution of the longitudinal and transverse ribs are taken as absolute values, and any longitudinal rib Z is examined. n Any rib segment on The maximum stress value under this local load condition is recorded as Similarly, any transverse rib H m Any rib segment on The maximum stress value under the jth local load condition is Define the maximum stress reduction factor λ, where 0≤λ≤1, if or but or The small segment of the reinforcement is defined as the important local load stress area under the jth local load condition.

[0020] Preferably, the maximum stress reduction factor λ is taken as 0.8.

[0021] In a possible embodiment, in step 4, the position of the longitudinal or transverse overall force transmission path is determined according to the important overall load stress area, and the method is as follows: if a rib contains one or more important overall load stress areas, then the entire rib is the longitudinal or transverse overall force transmission path; the longitudinal or transverse overall force transmission path is divided into a longitudinal overall force transmission path and a transverse overall force transmission path; assuming that there are Each rib is the overall lateral force transmission path. Each rib is the overall longitudinal force transmission path; In the transverse overall force transmission path, all important overall load stress areas on any m-th transverse rib are examined, the stresses in these important overall load stress areas are compared, and the maximum value is extracted and defined as s max |H m ; According to s max |H m From large to small, mark the lateral overall force transmission path as Similarly, In the longitudinal overall force transmission path, according to the maximum stress value s of all important overall load stress areas of the longitudinal reinforcement max |Z n From large to small, the overall longitudinal force transmission path is marked as

[0022] Preferably, if there are multiple transverse ribs s max |H m The values ​​are the same, and they are marked from top to bottom; if there are multiple longitudinal ribs s max |Z n The values ​​are the same and are marked from left to right.

[0023] In a possible embodiment, in step 5, all longitudinal local force transmission paths under any j-th local load condition are extracted. and all lateral local force paths The maximum stress of all important local load stress areas is recorded as Where 1≤j≤J, that is According to the value from large to small Arrange, and calculate the continuous length of the longitudinal or transverse local force transmission path under the jth local load condition in this order;

[0024] Determine the longitudinal local force transmission path under any j-th local load condition The continuous length method is, where For any The maximum stress value of any important local load stress area If it is at junction A n,m With A n,m+1 The maximum stress value is The rib segment As the starting point, along The ribs extend in both directions until they are terminated as follows:

[0025] (1) Extend to The adjacent t1th transverse rib is terminated;

[0026] (2) When extended to the outer frame edge H0 or H M+1 , ending at the outer frame edge;

[0027] (3) When extending into any continuous length of any transverse local force transmission path, excluding the two end points of the continuous length of the transverse local force transmission path, it ends at the intersection with the continuous length of the transverse local force transmission path;

[0028] For any The maximum stress value of any important local load stress area If it is at junction A n,m or A n,m+1 The maximum stress value is The intersection is the starting point, along The ribs extend in both directions until they are terminated as follows:

[0029] (1) Extend to The adjacent t2th transverse rib is terminated;

[0030] (2) When extended to the outer frame edge H0 or H M+1 , ending at the outer frame edge;

[0031] (3) When extending into any continuous length of any transverse local force transmission path, excluding the two end points of the continuous length of the transverse local force transmission path, it ends at the intersection with the continuous length of the transverse local force transmission path;

[0032] Determine the lateral local force transmission path under any j-th local load condition The continuous length method is, where For any The maximum stress value of any important local load stress area If it is at junction A n,m With A n+1,m The maximum stress value is The rib segment As the starting point, along The ribs extend in both directions until they are terminated as follows:

[0033] (1) Extend to The adjacent t3th transverse rib is terminated;

[0034] (2) When extended to the outer frame edge Z0 or Z N+1 , ending at the outer frame edge;

[0035] (3) When extending to any continuous length of any longitudinal local force transmission path, excluding the two end points of the continuous length of the longitudinal local force transmission path, it ends at the intersection with the continuous length of the longitudinal local force transmission path;

[0036] For any The maximum stress value of any important local load stress area If it is at junction A n,m , A n+1,m The maximum stress value is The rib segment As the starting point, along The ribs extend in both directions until they are terminated as follows:

[0037] (1) Extend to The adjacent t4th transverse rib is terminated;

[0038] (2) When extended to the outer frame edge Z0 or Z N+1 , ending at the outer frame edge;

[0039] (3) When extending to any continuous length of any longitudinal local force transmission path, it does not include the two end points of the continuous length of the longitudinal local force transmission path and terminates at the intersection with the continuous length of the longitudinal local force transmission path.

[0040] Preferably, the longitudinal or transverse local force transmission path should be located on the longitudinal or transverse overall force transmission path.

[0041] Preferably, for the longitudinal or transverse local force transmission path under the jth local load condition, for the maximum stress value q in the important local load stress area max |H m The same transverse ribs are marked in order from top to bottom; for the maximum stress value q in the important local load stress area max |Z n The same longitudinal ribs are marked in order from left to right.

[0042] Preferably, Located at Junction A n,m With A n,m+1 When the longitudinal local force transmission path is between The second adjacent cross rib H m-1 , H m+2 until.

[0043] Preferably, Located at Junction A n,m or A n,m+1 When the longitudinal local force transmission path is continuous, the length ends at The first adjacent cross rib H m-1 , H m+1 (A n,m as the starting point) or H m+1 , H m+2 (A n,m+1 as the starting point).

[0044] In a possible embodiment, in step 5, all longitudinal local force transmission paths under any j-th local load condition are extracted. and all lateral local force paths The maximum stress of all important local load stress areas is recorded as Where 1≤j≤J, that is According to the value from large to small Arrange in this order, and calculate the continuous length of the longitudinal or transverse local force transmission path under the jth local load condition in this order.

[0045] When the continuous lengths of different longitudinal or transverse local force transmission paths on the same rib overlap (not counting the end-to-end connections), they should be integrated into one longitudinal or transverse local force transmission path, that is, the continuous length of this force transmission path is the superposition of the continuous lengths of the original several local force transmission paths.

[0046] In a possible embodiment, in step 5, all longitudinal or transverse overall force transmission paths should be divided according to the maximum stress value s of the important overall load stress zone thereon. max |H m and max |Z n Arrange them from small to large, and calculate the continuous length of the longitudinal or lateral overall force transmission path in this order.

[0047] In a possible embodiment, in step 5, the longitudinal overall force transmission path is determined The method of the continuous length is: for any longitudinal overall force transmission path Any important overall load stress area on it The maximum stress value is like Located at Junction A n,m With A n,m+1 Between The rib segment As the starting point, along The ribs extend to both sides; if Located at Junction A n,m or A n,m+1 On, the intersection point A n,m or A n,m+1 As the starting point, along The ribs extend to both sides until the following conditions are met (e.g. Figure 5 shown):

[0048] (1) When extended to any Any important overall load stress area and The intersection point A n,y When Less than The maximum stress value of the important overall load stress area is n,y The deadline is

[0049] (2) When extended to the outer frame edge H0 or H M+1 , ending at the outer frame edge;

[0050] (3) When extending to any longitudinal or transverse local force transmission path (excluding the two side end points of the longitudinal or transverse local force transmission path), it is terminated at the intersection with the longitudinal or transverse local force transmission path.

[0051] In a possible embodiment, in step 5, when there is overlap in the continuous lengths between any different longitudinal overall force transmission paths and between any longitudinal overall force transmission path and any longitudinal local force transmission path on the same rib (not counting the end-to-end connections), they should be integrated into one longitudinal overall force transmission path, that is, the continuous length of this force transmission path is the superposition of the continuous lengths of the original several force transmission paths.

[0052] In a possible embodiment, in step 5, the overall lateral force transmission path is determined. The method of the continuous length is: for any longitudinal overall force transmission path Any important overall load stress area on it The maximum stress value is like Located at Junction A n,m With A n+1,m Between The rib segment As the starting point, along The ribs extend to both sides; if Located at Junction A n,m or A n+1,m On, the intersection point A n,mor A n+1,m As the starting point, along The ribs extend to both sides until the following conditions are met (e.g. Figure 5 shown):

[0053] (1) When extended to any Any important overall load stress area and The intersection point A x,m When Less than The maximum stress value of the important overall load stress area is x,m The deadline is

[0054] (2) When extended to the outer frame edge Z0 or Z N+1 , ending at the outer frame edge;

[0055] (3) When extending to any longitudinal or transverse local force transmission path (excluding the two side end points of the longitudinal or transverse local force transmission path), it is terminated at the intersection with the longitudinal or transverse local force transmission path.

[0056] In a possible embodiment, in step 5, when there is overlap in the continuous lengths between any different lateral overall force transmission paths and between any lateral overall force transmission path and any lateral local force transmission path on the same rib (excluding those connected end to end), they should be integrated into one lateral overall force transmission path, that is, the continuous length of this force transmission path is the superposition of the continuous lengths of the original several force transmission paths.

[0057] In a possible embodiment, in step 6, the ply design method is as follows: for the longitudinal or transverse ribs on the longitudinal or transverse overall force transmission path and the longitudinal or transverse local force transmission path, within their continuous length, the thickness of the continuous ply is not less than 25% of the total thickness of the ribs at that location; the thickness of the continuous ply of the outer frame edge is not less than 25% of the total thickness of the outer frame edge at that location; and a compensation layer should be added in the direction in which the ribs are disconnected to meet the rib thickness design requirements.

[0058] The invention has the following beneficial effects: by marking the frame edge, longitudinal or transverse ribs and the intersection of longitudinal or transverse ribs of the composite material integral reinforced frame, a quantifiable and accurate analysis basis is provided for determining the position and continuous length of the longitudinal or transverse overall main force transmission path and the longitudinal or transverse local force transmission path; by adopting a series of finite element simulation analysis methods such as determining the grid size by mesh convergence analysis, setting isotropic materials, simplifying actual boundaries, static linear analysis methods, extracting von Mises independent node stress distribution, etc., the engineering analysis accuracy requirements of the preliminary design of the composite material integral reinforced frame are met, and the calculation efficiency of the composite material integral reinforced frame is improved; by adopting the maximum stress reduction coefficient method, the important overall load stress area and the important local load stress area of ​​the longitudinal or transverse ribs concerned by the designer can be accurately extracted, and the non-important stress area can be ignored, thereby laying a foundation for accurately analyzing the position and continuous length of the longitudinal or transverse overall force transmission path and the longitudinal or transverse local force transmission path; by setting the cutoff criterion extending from the important local load stress area and the superposition principle of the continuous length of multiple longitudinal or transverse local force transmission paths, a method for accurately determining the continuous length of the longitudinal or transverse local force transmission path is provided; By setting a cutoff criterion extending from an important overall load stress area and a superposition principle between multiple longitudinal or transverse overall force transmission paths and between the continuous lengths of the longitudinal or transverse overall force transmission paths and the longitudinal or transverse local force transmission paths, a method for accurately determining the continuous length of the longitudinal or transverse overall force transmission paths is provided; by giving the minimum continuous ply thickness requirement and the non-continuous ply area thickness coordination requirement within the continuous length of the longitudinal or transverse overall force transmission paths and the longitudinal or transverse local force transmission paths, a ply thickness design method is provided; this method systematically gives a ply design method for an integral longitudinal and transverse reinforced frame of a composite material, solves the ply design problem of which ribs in the longitudinal or transverse reinforcement should be continuous and which ribs should be disconnected, and improves the overall mechanical properties of the integral longitudinal and transverse reinforced frame of the composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 Schematic diagram of the process of the present invention

[0060] Figure 2 Schematic diagram of the definition of the frame edge, longitudinal ribs, transverse ribs and the intersection of the longitudinal and transverse ribs of the composite material integral longitudinal and transverse reinforcement frame in step 1 of the present invention

[0061] Figure 3 The longitudinal or transverse local force transmission path in which the maximum stress value of any important local load stress zone under the jth local load condition in step 5 of the present invention is located within the rib segment or The method for determining the continuous length of For example)

[0062] Figure 4is the longitudinal or transverse local force transmission path where the maximum stress value of any important local load stress zone under the jth local load condition in step 5 of the present invention is located at the intersection of the ribs or The method for determining the continuous length of For example)

[0063] Figure 5 Any longitudinal or transverse overall force transmission path in step 5 of the present invention or Method for determining the continuous length (based on For example)

[0064] Figure 6 (a) is a schematic diagram of the longitudinal and transverse reinforcement layout and load conditions of the composite integral longitudinal and transverse stiffened plate of Example 1 of the present invention

[0065] Figure 6 (b) is a schematic diagram of the definition of the frame edge, longitudinal ribs, transverse ribs and the intersection of the longitudinal and transverse ribs of the composite material integral longitudinal and transverse stiffened plate of Example 1 of the present invention

[0066] Figure 7 (a) is a schematic diagram of the maximum stress distribution of all rib segments of the composite material integral longitudinal and transverse stiffened plate under all load conditions in Example 1 of the present invention (unit: MPa)

[0067] Figure 7 (b) is a schematic diagram of the important overall load stress area and overall force transmission path position of the composite integral longitudinal and transverse stiffened plate of Example 1 of the present invention

[0068] Figure 8 (a) is a schematic diagram of the continuous length of all overall force transmission paths of the composite material integral longitudinal and transverse stiffened plate of Example 1 of the present invention;

[0069] Figure 8 (b) is a schematic diagram of the design of the composite material integral longitudinal and transverse stiffened plate ply in Example 1 of the present invention;

[0070] Fig. 9 (a) is a schematic diagram of the longitudinal and transverse reinforcement layout and load conditions of the composite integral longitudinal and transverse stiffened plate of Example 2 of the present invention

[0071] Fig. 9 (b) is a schematic diagram of the definition of the frame edge, longitudinal ribs, transverse ribs and the intersection of the longitudinal and transverse ribs of the composite material integral longitudinal and transverse stiffened plate of Example 2 of the present invention

[0072] Fig.10 (a) is a schematic diagram of the maximum stress distribution of all rib segments of the composite material integral longitudinal and transverse stiffened plate of Example 2 of the present invention under all overall load conditions (unit: MPa)

[0073] Fig.10 (b) is a schematic diagram of the important overall load stress area and overall force transmission path position of the composite integral longitudinal and transverse stiffened plate of Example 2 of the present invention

[0074] Fig.11 (a) is a schematic diagram of the maximum stress distribution of all rib segments of the composite integral longitudinal and transverse stiffened plate of Example 2 of the present invention under all local load conditions (unit: MPa)

[0075] Fig.11 (b) is a schematic diagram of the location of important local load stress areas and local force transmission paths of the composite integral longitudinal and transverse stiffened plate of Example 2 of the present invention

[0076] Fig.12 (a) is a schematic diagram of the continuous length of all overall force transmission paths and local force transmission paths of the composite integral longitudinal and transverse stiffened plate of Example 2 of the present invention

[0077] Fig.12 (b) is a schematic diagram of the layup design of the composite material integral longitudinal and transverse stiffened plate according to Example 2 of the present invention. DETAILED DESCRIPTION

[0078] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0079] like Figure 1 As shown, a composite material integral longitudinal and transverse reinforced frame ply design method comprises the following steps:

[0080] Step 1: Determine the load conditions, longitudinal and transverse reinforcement layout, and dimensional parameters of the reinforced plate of the composite material integral longitudinal and transverse reinforced frame, and mark the frame edge, longitudinal ribs, transverse ribs, and the intersection of longitudinal and transverse ribs in the specified order;

[0081] Step 2: Conduct static analysis on the stress conditions of the composite material integral longitudinal and transverse reinforced frame under various load conditions to obtain the stress distribution of the longitudinal and transverse ribs on the composite material integral longitudinal and transverse reinforced frame under various load conditions;

[0082] Step 3: According to the stress distribution of the longitudinal and transverse ribs on the composite material integral longitudinal and transverse reinforcement frame under various load conditions, the maximum stress reduction coefficient method is used to extract and mark the important overall load stress area and the important local load stress area on the longitudinal and transverse ribs;

[0083] Step 4: Determine the longitudinal and transverse overall force transmission paths and the longitudinal and transverse local force transmission path positions according to the important overall load stress areas and important local load stress areas of the overall longitudinal and transverse reinforced frame of the composite material;

[0084] Step 5: According to the important local load stress area of ​​the overall longitudinal and transverse reinforced frame of the composite material, and the positions of the longitudinal and transverse local force transmission paths, respectively determine the continuous lengths of the longitudinal and transverse local force transmission paths; According to the important overall load stress area of ​​the overall longitudinal and transverse reinforced frame of the composite material, and the positions of the longitudinal and transverse overall force transmission paths, respectively determine the continuous lengths of the longitudinal and transverse overall force transmission paths;

[0085] Step 6: Design the ply according to the continuous length of each longitudinal and transverse overall main force transmission path and longitudinal and transverse local force transmission path.

[0086] In a possible embodiment, the load condition includes an overall load condition and a local load condition; the overall load includes but is not limited to longitudinal tension, transverse tension, longitudinal compression, transverse compression, longitudinal bending, transverse bending, in-plane shear, and out-of-plane pressure load; the overall load condition is a combination of one or more of the above-mentioned overall loads; the local load includes but is not limited to the equipment installation load installed on one or several ribs, the actuator load, and the hanging point load; the local load condition is a single combination of the above-mentioned local loads.

[0087] In a possible embodiment, the overall load condition may be one or more, and the local load condition may be none, one, or more.

[0088] In a possible embodiment, in step 1, the method for marking the frame edge, longitudinal ribs, transverse ribs, and the intersection of the longitudinal and transverse ribs of the composite material integral longitudinal and transverse reinforced frame is as follows:

[0089] In a possible embodiment, in step 1, the outer edge bars and longitudinal or transverse ribs of the reinforced frame are marked in order from top to bottom and from left to right; wherein, in order from top to bottom, the transverse outer frame edge and the transverse ribs are marked as H0, H1, H2, ... H m , ...H M+1 , where M is the number of transverse ribs, 1≤m≤M; H0 represents the uppermost outer frame edge, H N+1 Indicated as the bottom outer frame edge; H1, H2, ... H m , ...H M Indicates the 1st, 2nd, ..., m, ...Mth transverse ribs from top to bottom; similarly, from left to right, the longitudinal outer frame edges and longitudinal ribs are marked as Z0, Z1, Z2, ...Z n ,...Z N+1, where N is the number of longitudinal ribs, 1≤n≤N; from top to bottom and from left to right, mark the intersection between the longitudinal and transverse ribs as A n,m , represents the intersection point between the nth longitudinal rib and the mth transverse rib; the marking method of the intersection points between the frame edges and the frame edges and the ribs is the same; from top to bottom and from left to right, mark the intersection point A n,m With A n,m+1 The ribs between are marked as Indicates the longitudinal rib Z n On the top, the rib segment is divided by the mth and m+1th transverse ribs; the intersection point A n,m With A n+1,m The ribs between are marked as Indicates the transverse rib H m The rib segments are divided by the nth and n+1th longitudinal ribs. According to the definition, the transverse rib H m Depend on Connected end to end, longitudinal ribs Z n Depend on Connect end to end, such as Figure 2 shown.

[0090] In a possible embodiment, in step 2, finite element simulation analysis is used to perform finite element modeling on the composite material longitudinal and transverse reinforcement frame using shell units or solid units, and the grid size is determined according to the results of grid convergence analysis; the material of the composite material overall longitudinal and transverse reinforcement frame is simplified to an isotropic material, the load conditions are set to each load condition in turn, the boundary conditions are simplified according to the actual boundaries of the composite material overall longitudinal and transverse reinforcement frame, and the static linear analysis method is used to calculate the longitudinal or transverse reinforcement von Mises stress distribution of the composite material overall longitudinal and transverse reinforcement frame under each load condition.

[0091] Preferably, the finite element unit type is a linear, finite membrane strain, reduced integral quadrilateral shell unit; the stress error threshold of the mesh convergence analysis is set to 5%; the material is set to aluminum alloy material; the frame edge boundary condition is set to simply supported; the static linear analysis method is the Full Newton algorithm; and the von Mises stress extracts the unique nodal stress.

[0092] In a possible embodiment, in step 3, the maximum stress reduction coefficient method is used to extract and mark the important overall load stress areas under all overall load conditions. The method is as follows: assuming that there are I overall load conditions, for any i-th (1≤i≤I) overall load condition, the negative stress value in the longitudinal or transverse reinforcement von Mises stress distribution is taken as the absolute value, and any longitudinal rib Z is examined. nAny rib segment on The maximum stress value under this overall load condition is recorded as The maximum stress value of the rib segment under I overall load conditions is set as a set, and the maximum value of the set is defined as Right now Similarly, any transverse rib H m Any rib segment on The maximum stress value under all overall load conditions is The maximum stress values ​​s of all longitudinal or transverse reinforced rib segments under all overall load conditions are calculated in descending order. max Arrange, get The value 2MN+M+N represents the number of all rib segments contained in N longitudinal ribs and M transverse ribs. Define the maximum stress reduction factor η, where 0≤η≤1, if Where 1≤x≤2MN+M+N, then The small segment of the reinforcement is defined as the important overall load stress area.

[0093] Preferably, the maximum stress reduction factor η is taken as 0.8.

[0094] In one possible embodiment, in step 3, the maximum stress reduction coefficient method is used to extract and mark the important local load stress areas under all local load conditions. The method is as follows: assuming that there are J local load conditions in total, for any j-th (1≤j≤J) local load condition, the negative stress value in the longitudinal or transverse reinforcement von Mises stress distribution is taken as the absolute value, and any longitudinal rib Z is examined. n Any rib segment on The maximum stress value under this local load condition is recorded as Generally speaking, the maximum stress of this type is located at the installation location of the equipment, actuator, hanging point, etc. Similarly, any transverse rib H m Any rib segment on The maximum stress value under the jth local load condition is Define the maximum stress reduction factor λ, where 0≤λ≤1, if or but or The small segment of the reinforcement is defined as the important local load stress area under the jth local load condition.

[0095] Preferably, the maximum stress reduction factor λ is taken as 0.8.

[0096] In a possible embodiment, in step 4, the position of the longitudinal or transverse overall force transmission path is determined according to the important overall load stress area, and the method is: if a rib contains one or more important overall load stress areas, then the entire rib is the longitudinal or transverse overall force transmission path. The longitudinal or transverse overall force transmission path is divided into a longitudinal overall force transmission path and a transverse overall force transmission path. Assume that there are Each rib is the overall lateral force transmission path. The ribs are the overall longitudinal force transmission path. In the transverse overall force transmission path, all important overall load stress areas on any m-th transverse rib are examined, the stresses in these important overall load stress areas are compared, and the maximum value is extracted and defined as s max |H m . According to s max |H m From large to small, mark the lateral overall force transmission path as If there are multiple transverse ribs max |H m If the values ​​are the same, they are marked in a certain order. In the longitudinal overall force transmission path, according to the maximum stress value s of all important overall load stress areas of the longitudinal reinforcement max |Z n From large to small, the overall longitudinal force transmission path is marked as If there are multiple longitudinal ribs s max |Z n If the values ​​are the same, they are marked in a certain order.

[0097] Preferably, if there are multiple transverse ribs s max |H m The values ​​are the same, and they are marked from top to bottom; if there are multiple longitudinal ribs s max |Z n The values ​​are the same and are marked from left to right.

[0098] In a possible embodiment, in step 4, the position of the longitudinal or transverse local force transmission path is determined according to the important local load stress area, and the method is: for any j-th local load condition, if a rib contains one or more important local load stress areas, then the entire rib is the longitudinal or transverse local force transmission path under the j-th local load condition. The longitudinal or transverse local force transmission path is divided into a longitudinal local force transmission path and a transverse local force transmission path. Assuming that there are a total of Each rib is a local transverse force transmission path. Each rib is a local longitudinal force transmission path. In the transverse local force transmission path, all important local load stress areas on any m-th transverse rib are examined, the stresses in these important local load stress areas are compared, and the maximum value is extracted and defined as q max |H m , according to q max |H m From large to small, the lateral local force transmission paths are marked as If there are multiple transverse ribs q max |H m If the values ​​are the same, they are marked in a certain order. In the longitudinal local force transmission path, according to the maximum stress value q of all important local load stress areas of the longitudinal reinforcement max |Z n From large to small, the overall longitudinal force transmission path is marked as If there are multiple longitudinal ribs q max |Z n If the values ​​are the same, they are marked in a certain order.

[0099] Preferably, the longitudinal or transverse local force transmission path should be located on the longitudinal or transverse overall force transmission path.

[0100] Preferably, for the longitudinal or transverse local force transmission path under the jth local load condition, for the maximum stress value q in the important local load stress area max |H m The same transverse ribs are marked in order from top to bottom; for the maximum stress value q in the important local load stress area max |Z n The same longitudinal ribs are marked in order from left to right.

[0101] In a possible embodiment, in step 5, the longitudinal local force transmission path under any j-th local load condition is determined. The continuous length method is: for any The maximum stress value of any important local load stress area Located at Junction A n,m With A n,m+1 The maximum stress value is The rib segment As the starting point, along The ribs extend to both sides until they meet An adjacent cross rib is cut off. Located at Junction A n,m or A n,m+1 The maximum stress value is The intersection is the starting point, along The ribs extend to both sides until they meet An adjacent cross rib is terminated.

[0102] Preferably, Located at Junction A n,m With A n,m+1 When the longitudinal local force transmission path is between The second adjacent cross rib H m-1 , H m+2 So far. Figure 3 shown.

[0103] Preferably, Located at Junction A n,m or A n,m+1 When the longitudinal local force transmission path is continuous, the length ends at The first adjacent cross rib H m-1 , H m+1 (A n,m as the starting point) or H m+1 , H m+2 (A n,m+1 As the starting point). Figure 4 shown.

[0104] In a possible embodiment, in step 5, the lateral local force transmission path under any j-th local load condition is determined. The continuous length method is: for any The maximum stress value of any important local load stress area Located at Junction A n,m With A n+1,m The maximum stress value is The rib segment As the starting point, along The ribs extend to both sides until they meet An adjacent cross rib is cut off. Located at Junction A n,m , A n+1,m The maximum stress value is The intersection is the starting point, along The ribs extend to both sides until they meet An adjacent cross rib is terminated.

[0105] Preferably, Located at Junction A n,m With A n+1,m When the longitudinal local force transmission path is between The second adjacent cross rib Z n-1 , Zn+2 So far. Figure 3 shown.

[0106] Preferably, Located at Junction A n,m , A n+1,m When the longitudinal local force transmission path is continuous, the length ends at The first adjacent cross rib Z n-1 , Z n+1 (A n,m as the starting point) or Z n , Z n+2 (A n+1,m As the starting point). Figure 4 shown.

[0107] In a possible embodiment, in step 5, when the continuous lengths of different longitudinal or transverse local force transmission paths on the same rib overlap (not counting those connected end to end), they should be integrated into one longitudinal or transverse local force transmission path, that is, the continuous length of the force transmission path is the superposition of the continuous lengths of the original several local force transmission paths.

[0108] In a possible embodiment, in step 5, all longitudinal or transverse overall force transmission paths should be divided according to the maximum stress value s of the important overall load stress zone thereon. max |H m and max |Z n Arrange them from small to large, and calculate the continuous length of the longitudinal or lateral overall force transmission path in this order.

[0109] In a possible embodiment, in step 5, the longitudinal overall force transmission path is determined The method of the continuous length is: for any longitudinal overall force transmission path Any important overall load stress area on it The maximum stress value is like Located at Junction A n,m With A n,m+1 Between The rib segment As the starting point, along The ribs extend to both sides; if Located at Junction A n,m or A n,m+1 On, the intersection point A n,m or A n,m+1 As the starting point, along The ribs extend to both sides until the following conditions are met (e.g. Figure 5 shown):

[0110] (1) When extended to any Any important overall load stress area and The intersection point A n,y When Less than The maximum stress value of the important overall load stress area is n,y The deadline is

[0111] (2) When extended to the outer frame edge H0 or H M+1 , ending at the outer frame edge;

[0112] (3) When extending to any longitudinal or transverse local force transmission path (excluding the two side end points of the longitudinal or transverse local force transmission path), it is terminated at the intersection with the longitudinal or transverse local force transmission path.

[0113] In a possible embodiment, in step 5, when there is overlap in the continuous lengths between any different longitudinal overall force transmission paths and between any longitudinal overall force transmission path and any longitudinal local force transmission path on the same rib (not counting the end-to-end connections), they should be integrated into one longitudinal overall force transmission path, that is, the continuous length of this force transmission path is the superposition of the continuous lengths of the original several force transmission paths.

[0114] In a possible embodiment, in step 5, the overall lateral force transmission path is determined. The method of the continuous length is: for any longitudinal overall force transmission path Any important overall load stress area on it The maximum stress value is like Located at Junction A n,m With A n+1,m Between The rib segment As the starting point, along The ribs extend to both sides; if Located at Junction A n,m or A n+1,m On, the intersection point A n,m or A n+1,m As the starting point, along The ribs extend to both sides until the following conditions are met (e.g. Figure 5 shown):

[0115] (1) When extended to any Any important overall load stress area and The intersection point A x,m When Less than The maximum stress value of the important overall load stress area isx,m The deadline is

[0116] (2) When extended to the outer frame edge Z0 or Z N+1 , ending at the outer frame edge;

[0117] (3) When extending to any longitudinal or transverse local force transmission path (excluding the two side end points of the longitudinal or transverse local force transmission path), it is terminated at the intersection with the longitudinal or transverse local force transmission path.

[0118] In a possible embodiment, in step 5, when there is overlap in the continuous lengths between any different lateral overall force transmission paths and between any lateral overall force transmission path and any lateral local force transmission path on the same rib (excluding those connected end to end), they should be integrated into one lateral overall force transmission path, that is, the continuous length of this force transmission path is the superposition of the continuous lengths of the original several force transmission paths.

[0119] In a possible embodiment, in step 6, the ply design method is as follows: for the longitudinal or transverse ribs on the longitudinal or transverse overall force transmission path and the longitudinal or transverse local force transmission path, within their continuous length, the thickness of the continuous ply is not less than 25% of the total thickness of the ribs at that location; the thickness of the continuous ply of the outer frame edge is not less than 25% of the total thickness of the outer frame edge at that location; and a compensation layer should be added in the direction in which the ribs are disconnected to meet the rib thickness design requirements.

[0120] Embodiment 1

[0121] The composite material integral longitudinal and transverse reinforced frame ply design method comprises the following steps:

[0122] Determine the load conditions, longitudinal and transverse reinforcement layout, and stiffened plate size parameters of the composite material integral longitudinal and transverse reinforcement frame. The longitudinal and transverse reinforcement layout of the composite material integral longitudinal and transverse reinforcement frame is: two longitudinal / transverse ribs, a single-sided longitudinal and transverse reinforcement frame with outer edge strips, such as Figure 6 (a) is shown. The dimensional parameters of the reinforced plate are: the length and width of the reinforced plate are 600mm, the spacing between the longitudinal and transverse reinforcing ribs is 200mm, the thickness of the web, ribs and flanges is 4mm, and the height of the ribs and flanges is 30mm. The load conditions are: there is only one overall load condition, which is the longitudinal in-plane compression load, and there is no local load condition. The reinforced frame is marked from left to right and from top to bottom, as shown in the figure. Figure 6 (b) as shown.

[0123] The ABAQUS finite element software was used to perform a static linear analysis on the reinforced frame structure and calculate the von Mises stress of the longitudinal or transverse reinforcement. The finite element unit type is a linear, finite membrane strain, and reduced integral quadrilateral shell unit; the stress error threshold of the mesh convergence analysis is set to 5%, and the mesh size is 2mmx2mm; the material is set to aluminum alloy; the frame edge boundary condition is set to simply supported; and the static linear analysis method is the Full Newton algorithm. Calculate and extract the maximum stress values ​​on all longitudinal and transverse rib segments. Where n is 1 or 2, and m is 1, such as Figure 7 (a)

[0124] According to the maximum stress values ​​on all longitudinal and transverse rib segments, the maximum stress value of the rib is located on the longitudinal rib, s max |Z n is 120Mpa, that is Taking the maximum stress reduction factor η as 0.8, all The small segments of the reinforcement bars are defined as important overall load stress areas, such as Figure 7 (b) as shown.

[0125] According to the definition of the important overall load stress area, the two longitudinal ribs are defined as the longitudinal overall force transmission path, and the positions of the two longitudinal overall force transmission paths are marked from left to right. and like Figure 7 (b) as shown.

[0126] from Start with As the starting point, along The ribs extend up and down until they reach the upper and lower frame edges. The continuous length of As the starting point, along The ribs extend up and down until they reach the upper and lower frame edges. The continuous length of Figure 8 (a)

[0127] The ply design of Example 1 is as follows: Figure 8 As shown in (b), each solid line in the figure represents a ply set with a thickness of 1 mm, two longitudinal ribs in the overall longitudinal or transverse force transmission path, including a 2 mm continuous layer in their continuous length, the thickness of the continuous layer accounts for 50% of the total thickness of the rib, a 2 mm compensation layer is added in the direction of the transverse rib disconnection to ensure that the transverse rib thickness is 4 mm, the outer frame edge of the reinforced plate includes a 2 mm continuous layer, the thickness of the continuous layer accounts for 50% of the total thickness of the frame edge.

[0128] Embodiment 2

[0129] The composite material integral longitudinal and transverse reinforced frame ply design method comprises the following steps:

[0130] Determine the load conditions, longitudinal and transverse reinforcement layout, and stiffened plate size parameters of the composite material integral longitudinal and transverse reinforcement frame. The longitudinal and transverse reinforcement layout of the composite material integral longitudinal and transverse reinforcement frame is: two longitudinal / transverse ribs, a single-sided longitudinal and transverse reinforcement frame with outer edge strips, such as Fig. 9 (a). The dimensional parameters of the reinforced plate are: the length and width of the reinforced plate are 600mm, the spacing between the longitudinal and transverse reinforcing ribs is 200mm, the thickness of the web, ribs and flanges is 4mm, and the height of the ribs and flanges is 30mm. The load conditions are: there is only one overall load condition, which is the longitudinal in-plane compression load; there is only one local load condition, which is the equipment installation load (the lateral concentrated force at the installation point on the rib). Mark the reinforced frame from left to right and from top to bottom, such as Fig. 9 (b) as shown.

[0131] The ABAQUS finite element software is used to perform a static linear analysis on the above-mentioned reinforced frame structure to calculate the von Mises stress of its longitudinal or transverse reinforcement. The finite element unit type is a linear, finite membrane strain, and reduced integral quadrilateral shell unit; the stress error threshold of the mesh convergence analysis is set to 5%, and the mesh size is 2mmx2mm; the material is set to aluminum alloy material; the frame edge boundary condition is set to simply supported; and the static linear analysis method is the Full Newton algorithm. Calculate and extract the maximum stress values ​​on all longitudinal and transverse rib segments under all overall load conditions. Where n is 1 or 2, and m is 1, such as Fig.10 (a) is shown. Calculate and extract the maximum stress values ​​of all longitudinal and transverse rib segments under each local load condition. Where j is 1, n is 0 or 2, and m is 2. Fig.11 (a) shown.

[0132] According to the maximum stress values ​​of all longitudinal and transverse rib segments under all overall load conditions, the maximum stress value is located on the longitudinal rib, s max |Z n is 120Mpa, that is Taking the maximum stress reduction factor η as 0.8, all The small segments of the reinforcement bars are defined as important overall load stress areas, such as Fig.10 (b). Taking the maximum stress reduction factor λ as 0.8, all or The small segments of the reinforcement bars are defined as important local load stress areas, such as Fig.11 (b) as shown.

[0133] According to the definition of the important overall load stress area, the two longitudinal ribs are defined as the longitudinal overall force transmission path, and the positions of the two longitudinal overall force transmission paths are marked from left to right. and like Fig.10 According to the definition of important local load stress area, the H2 transverse rib is defined as the transverse local force transmission path under local load condition 1, marked as like Fig.11 (b) as shown.

[0134] First, determine the continuous length of the local force transmission path. Start with As the starting point, along The ribs extend left and right, the left side extends to the left frame edge, and the right side extends to On the adjacent second longitudinal rib Z2; As the starting point, along The ribs extend left and right, the right side extends to the right frame edge, and the left side extends to On the adjacent second longitudinal rib Z1. Since the continuous lengths of the two longitudinal local force transmission paths overlap, the union of the two continuous lengths is taken to obtain the final The only continuous length on the surface. Then determine the continuous length of the overall force transmission path. Start with As the starting point, along The ribs extend up and down, the upper side extends to the upper frame edge, and the lower side extends to The continuous length ends; then As the starting point, along The ribs extend up and down, the upper side extends to the upper frame edge, and the lower side extends to The continuous length is cut off, such as Fig.12 (a) shown.

[0135] According to the continuous direction and continuous length of the longitudinal or transverse stiffener strips in the second embodiment, the ply design is performed, such as Fig.12 As shown in (b), each solid line in the figure represents a ply set with a thickness of 1 mm. and The longitudinal ribs include a 2 mm continuous layer over the continuous length of the overall force transmission path, and the thickness of the continuous layer accounts for 50% of the total thickness of the ribs. The transverse ribs include a 1mm continuous layer in the continuous length, and the thickness of the continuous layer accounts for 25% of the total thickness of the ribs. The longitudinal / transverse ribs have a 2mm compensation layer added in the disconnection direction to ensure the rib thickness of 4mm. The outer edge strip of the stiffened plate includes a 2mm continuous layer, and the thickness of the continuous layer accounts for 50% of the total thickness of the edge strip.

[0136] The above is only a specific embodiment of the present invention, and the present invention is described in detail. The unexplained part is a conventional technology. However, the protection scope of the present invention is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A composite material integral longitudinal and transverse reinforced frame ply design method, characterized in that: The steps include: Step 1: Determine the load conditions, longitudinal and transverse reinforcement layout, and dimensional parameters of the reinforced plate of the composite material integral longitudinal and transverse reinforced frame, and mark the frame edge, longitudinal ribs, transverse ribs, and the intersection of longitudinal and transverse ribs in the specified order; Step 2: Conduct static analysis on the stress conditions of the composite material integral longitudinal and transverse reinforced frame under various load conditions to obtain the stress distribution of the longitudinal and transverse ribs on the composite material integral longitudinal and transverse reinforced frame under various load conditions; Step 3: According to the stress distribution of the longitudinal and transverse ribs on the composite material integral longitudinal and transverse reinforcement frame under various load conditions, the maximum stress reduction coefficient method is used to extract and mark the important overall load stress area and the important local load stress area on the longitudinal and transverse ribs; In step 3, the maximum stress reduction coefficient method is used to extract and mark the important overall load stress areas under all overall load conditions. The method is as follows: assuming that there are I overall load conditions, for any i-th overall load condition, where 1≤i≤I, the negative stress values ​​in the von Mises stress distribution of the longitudinal and transverse ribs are taken as absolute values, and any longitudinal rib Z is examined. n Any rib segment on The maximum stress value under this overall load condition is recorded as The maximum stress value of the rib segment under I overall load conditions is set as a set, and the maximum value of the set is defined as Right now Similarly, any transverse rib H m Any rib segment on The maximum stress value under all overall load conditions is The maximum stress values ​​s of all longitudinal and transverse rib segments under all overall load conditions are calculated in descending order. max Arrange, get The value 2MN+M+N represents the number of all rib segments contained in N longitudinal ribs and M transverse ribs; the maximum stress reduction factor η is defined, where 0≤η≤1, if Where 1≤x≤2MN+M+N, then The small segment of the reinforcement is defined as the important overall load stress area; The maximum stress reduction coefficient method is used to extract and mark the important local load stress areas under all local load conditions. The method is as follows: Assuming that there are J local load conditions, for any j-th local load condition, where 1≤j≤J, the negative stress values ​​in the von Mises stress distribution of the longitudinal and transverse ribs are taken as absolute values, and the maximum stress reduction coefficient method is used to extract and mark the important local load stress areas under all local load conditions. n Any rib segment on The maximum stress value under this local load condition is recorded as Similarly, any transverse rib H m Any rib segment on The maximum stress value under the jth local load condition is Define the maximum stress reduction factor λ, where 0≤λ≤1, if or but or The small segment of the reinforcement bar is defined as the important local load stress area under the jth local load condition; Step 4: Determine the longitudinal and transverse overall force transmission paths and the longitudinal and transverse local force transmission path positions according to the important overall load stress areas and the important local load stress areas of the overall longitudinal and transverse reinforced frame of the composite material; in said step 4, the longitudinal or transverse overall force transmission path position is determined according to the important overall load stress areas, and the method is as follows: if a certain rib contains one or more important overall load stress areas, then the entire rib is the longitudinal or transverse overall force transmission path; the longitudinal or transverse overall force transmission path is divided into the longitudinal overall force transmission path and the transverse overall force transmission path; assuming that there are Each rib is the overall lateral force transmission path. Each rib is the overall longitudinal force transmission path; In the transverse overall force transmission path, all important overall load stress areas on any m-th transverse rib are examined, the stresses in these important overall load stress areas are compared, and the maximum value is extracted and defined as s max |H m ; According to s max |H m From large to small, mark the lateral overall force transmission path as Similarly, In the longitudinal overall force transmission path, according to the maximum stress value s of all important overall load stress areas of the longitudinal reinforcement max |Z n From large to small, the overall longitudinal force transmission path is marked as The position of the longitudinal or transverse local force transmission path is determined according to the important local load stress area. The method is as follows: for any j-th local load condition, if a certain rib contains one or more important local load stress areas, then the entire rib is the longitudinal or transverse local force transmission path under the j-th local load condition; the longitudinal or transverse local force transmission path is divided into a longitudinal local force transmission path and a transverse local force transmission path; assuming that there are a total of Each rib is a local transverse force transmission path. Each rib is a longitudinal local force transmission path; In the transverse local force transmission path, all important local load stress areas on any m-th transverse rib are examined, the stresses in these important local load stress areas are compared, and the maximum value is extracted and defined as according to From large to small, the lateral local force transmission paths are marked as Similarly, In the longitudinal local force transmission path, according to the maximum stress value of all important local load stress areas of the longitudinal reinforcement, From large to small, the longitudinal local force transmission paths are marked as Step 5: According to the important local load stress area of ​​the overall longitudinal and transverse reinforced frame of the composite material, and the position of the longitudinal and transverse local force transmission paths, respectively determine the continuous length of the longitudinal and transverse local force transmission paths; According to the important overall load stress area of ​​the overall longitudinal and transverse reinforced frame of the composite material, and the position of the longitudinal and transverse overall force transmission paths, respectively determine the continuous length of the longitudinal and transverse overall force transmission paths; In the step 5, all longitudinal local force transmission paths under any j-th local load condition are extracted and all lateral local force transmission paths h1 j , The maximum stress of all important local load stress areas is recorded as Where 1≤j≤J, that is According to the value from large to small Arrange, and calculate the continuous length of the longitudinal or transverse local force transmission path under the jth local load condition in this order; Determine the longitudinal local force transmission path under any j-th local load condition The continuous length method is, where For any The maximum stress value of any important local load stress area If it is at junction A n,m With A n,m+1 The maximum stress value is The rib segment As the starting point, along The ribs extend in both directions until they are terminated as follows: (1) Extend to The adjacent t1th transverse rib is terminated; (2) When extended to the outer frame edge H0 or H M+1 , ending at the outer frame edge; (3) When extending into any continuous length of any transverse local force transmission path, excluding the two end points of the continuous length of the transverse local force transmission path, it ends at the intersection with the continuous length of the transverse local force transmission path; For any The maximum stress value of any important local load stress area If it is at junction A n,m or A n,m+1 The maximum stress value is The intersection is the starting point, along The ribs extend in both directions until they are terminated as follows: (1) Extend to The adjacent t2th transverse rib is terminated; (2) When extended to the outer frame edge H0 or H M+1 , ending at the outer frame edge; (3) When extending into any continuous length of any transverse local force transmission path, excluding the two end points of the continuous length of the transverse local force transmission path, it ends at the intersection with the continuous length of the transverse local force transmission path; Determine the lateral local force transmission path under any j-th local load condition The continuous length method is, where For any The maximum stress value of any important local load stress area If it is at junction A n,m With A n+1,m The maximum stress value is The rib segment As the starting point, along The ribs extend in both directions until they are terminated as follows: (1) Extend to The adjacent t3th transverse rib is terminated; (2) When extended to the outer frame edge Z0 or Z N+1 , ending at the outer frame edge; (3) When extending to any continuous length of any longitudinal local force transmission path, excluding the two end points of the continuous length of the longitudinal local force transmission path, it ends at the intersection with the continuous length of the longitudinal local force transmission path; For any The maximum stress value of any important local load stress area If it is at junction A n,m , A n+1,m The maximum stress value is The rib segment As the starting point, along The ribs extend in both directions until they are terminated as follows: (1) Extend to The adjacent t4th transverse rib is terminated; (2) When extended to the outer frame edge Z0 or Z N+1 , ending at the outer frame edge; (3) When extending to any continuous length of any longitudinal local force transmission path, excluding the two end points of the continuous length of the longitudinal local force transmission path, it ends at the intersection with the continuous length of the longitudinal local force transmission path; Step 6: Design the ply according to the continuous length of each longitudinal and transverse overall main force transmission path and longitudinal and transverse local force transmission path.

2. A composite material integral longitudinal and transverse reinforced frame ply design method according to claim 1, characterized in that: In step 1, the method for marking the frame edge, longitudinal ribs, transverse ribs and the intersection of the longitudinal and transverse ribs of the composite material integral longitudinal and transverse reinforced frame is as follows: Mark the outer edge strips and longitudinal or transverse ribs of the reinforced frame in the order from top to bottom and from left to right; among them, the transverse outer frame edge and transverse ribs are marked as H0, H1, H2, ... H in the order from top to bottom. m , ...H M+1 , where M is the number of transverse ribs, 1≤m≤M; H0 represents the uppermost outer frame edge, H N+1 Indicated as the bottom outer frame edge; H1, H2, ... H m , ...H M Indicates the 1st, 2nd, ..., m, ...Mth transverse ribs from top to bottom; similarly, from left to right, the longitudinal outer frame edges and longitudinal ribs are marked as Z0, Z1, Z2, ...Z n ,...Z N+1 , where N is the number of longitudinal ribs, 1≤n≤N; from top to bottom and from left to right, mark the intersection between the longitudinal and transverse ribs as A n,m , represents the intersection point between the nth longitudinal rib and the mth transverse rib; the marking method of the intersection points between the frame edges and the frame edges and the ribs is the same; from top to bottom and from left to right, mark the intersection point A n,m With A n,m+1 The ribs between are marked as Indicates the longitudinal rib Z n On the top, the rib segment is divided by the mth and m+1th transverse ribs; the intersection point A n,m With A n+1,m The ribs between are marked as Indicates the transverse rib H m The rib segments are divided by the nth and n+1th longitudinal ribs. According to the definition, the transverse rib H m Depend on Connected end to end, longitudinal rib Z n Depend on Connected end to end.

3. A composite material integral longitudinal and transverse reinforced frame ply design method according to claim 2, characterized in that: In the step 2, finite element simulation analysis is used to perform finite element modeling on the composite material longitudinal and transverse reinforced frame using shell units or solid units, and the mesh size is determined according to the mesh convergence analysis results; the material of the composite material overall longitudinal and transverse reinforced frame is simplified to be an isotropic material, the load conditions are set to each load condition in turn, the boundary conditions are simplified according to the actual boundaries of the composite material overall longitudinal and transverse reinforced frame, and the static linear analysis method is used to calculate the longitudinal and transverse rib von Mises stress distribution of the composite material overall longitudinal and transverse reinforced frame under each load condition.

4. A composite material integral longitudinal and transverse reinforced frame ply design method according to claim 1, characterized in that: In step 5, all longitudinal and transverse overall force transmission paths should be calculated according to the maximum stress values ​​s of all important overall load stress zones on them. max |H m and max |Z n Arrange them from small to large, and calculate the continuous length of the longitudinal or transverse overall force transmission path in this order; Determine the overall longitudinal force path The method of continuous length is, where, For any longitudinal overall force transmission path Any important overall load stress area on it The maximum stress value is like Located at Junction A n,m With A n,m+1 Between The rib segment As the starting point, along The ribs extend to both sides; if Located at Junction A n,m or A n,m+1 On, the intersection point A n,m or A n,m+1 As the starting point, along The ribs extend in both directions until they are terminated as follows: (1) When extended to any Any important overall load stress area and The intersection point A n,y When, among them, like Less than The maximum stress value of the important overall load stress area is n,y The deadline is (2) When extended to the outer frame edge H0 or H M+1 , ending at the outer frame edge; (3) When extending to any longitudinal or transverse local force transmission path, it does not include the two end points of the longitudinal or transverse local force transmission path and ends at the intersection with the longitudinal or transverse local force transmission path; Determine the overall lateral force path The method of the continuous length is: for any longitudinal overall force transmission path Any important overall load stress area on it The maximum stress value is like Located at Junction A n,m With A n+1,m Between The rib segment As the starting point, along The ribs extend to both sides; if Located at Junction A n,m or A n+1,m On, the intersection point A n,m or A n+1,m As the starting point, along The ribs extend in both directions until they are terminated as follows: (1) When extended to any in, Any important overall load stress area and The intersection point A x,m When Less than The maximum stress value of the important overall load stress area is x,m The deadline is (2) When extended to the outer frame edge Z0 or Z N+1 , ending at the outer frame edge; (3) When extended to any longitudinal or transverse local force transmission path, it does not include the two side endpoints of the longitudinal or transverse local force transmission path and ends at the intersection with the longitudinal or transverse local force transmission path.

5. A composite material integral longitudinal and transverse reinforced frame ply design method according to any one of claims 1 or 4, characterized in that: In step 5, when the continuous lengths of different local or overall force transmission paths on the same longitudinal rib or the same transverse rib overlap, the point overlap is not counted and they should be integrated into one local or overall force transmission path, that is, the continuous length of the force transmission path is the union of the continuous lengths of the original local or overall force transmission paths.

6. A composite material integral longitudinal and transverse reinforced frame ply design method according to claim 5, characterized in that: In step 6, the ply design method is as follows: for the longitudinal or transverse ribs on the longitudinal or transverse overall force transmission path or the longitudinal or transverse local force transmission path, within their continuous length, the thickness of the continuous ply shall not be less than 25% of the total thickness of the ribs at that location; the thickness of the continuous ply of the outer frame edge shall not be less than 25% of the total thickness of the outer frame edge at that location; a compensation layer shall be added in the direction in which the ribs are disconnected to meet the rib thickness design requirements.

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