A path planning method for continuous fiber 3D printing of composite material perforated plates

Abstract

The present application specifically relates to a method for planning a continuous fiber 3D printing path for a composite material perforated plate. For a perforated plate that is optimally designed based on the streamline equation of flow around an ideal fluid cylinder, the fiber printing path is planned so that the fiber printing path is continuous and the fiber printing path spacing is as small as possible while ensuring the minimum printing spacing, thereby meeting the manufacturing feasibility requirements and fully improving the mechanical properties of the perforated plate.

Description

Technical Field

[0001] The present application belongs to the technical field of continuous fiber 3D printing path planning for composite material perforated plates, and specifically relates to a continuous fiber 3D printing path planning method for composite material perforated plates. Background Art

[0002] Composite laminates are widely used in the aerospace field due to their excellent mechanical properties.

[0003] Traditional composite laminate design uses a linear fiber placement method, which cannot fully utilize the directional characteristics of composite fibers and limits the design freedom.

[0004] For composite material perforated plates with linear fiber laying, the presence of the holes will seriously destroy the continuity of the long fibers, change the force transmission route of the composite material perforated plates, and also cause stress concentration in the hole edge area due to the sudden change of local stiffness of the composite material perforated plates, which will significantly reduce the strength of the composite material perforated plates.

[0005] Laying the fibers of the composite material perforated plate along the curve around the hole can reduce the weight of the structure, reduce the stress concentration in the hole edge area, and improve the load-bearing efficiency of the composite material perforated plate.

[0006] Based on the streamline equation of ideal fluid flow around a circular cylinder, the fiber placement trajectory around the hole of the composite perforated plate is optimized, which can significantly improve the load-bearing efficiency of the perforated plate. The development of continuous fiber 3D printing technology makes the manufacture of the perforated plate possible.

[0007] In order to ensure manufacturing feasibility, general 3D printing equipment requires not only a continuous fiber printing path, but also a minimum printing spacing requirement. If the printing path spacing is too small, the fiber bundles will overlap a lot and the surface flatness requirement will not be met; if the printing path spacing is too large, the fiber volume content of the composite material will be reduced, reducing the mechanical properties of the structure. Therefore, the use of continuous fiber 3D printing technology to manufacture the perforated plate requires further planning of the optimized fiber printing path. In view of this, this application is proposed. Summary of the invention

[0008] The purpose of this application is to provide a method for planning the path of continuous fiber 3D printing of a composite material perforated plate, and to plan the fiber printing path for the perforated plate optimized based on the streamline equation of the flow around an ideal fluid cylinder.

[0009] The technical solution of this application is:

[0010] A composite material perforated plate continuous fiber 3D printing path planning method, comprising:

[0011] Step 1: Based on the length of the perforated plate ,width , determine the print area size, including the print area length ,width ;

[0012] Step 2: Take the uniform streamline flow direction as Axis direction, defining the local coordinate system ;

[0013] Step 3: In the local coordinate system Next, determine the upper half plane of the x' axis of the printing area;

[0014] Step 4: Divide the upper half plane of the x' axis of the printing area into the area where the streamline does not intersect with the hole circumference, the area where the streamline intersects with the hole circumference, and the area where the streamline overlaps with the x' axis;

[0015] Step 5: According to the printing continuity and the minimum printing spacing requirements, for the upper half plane of the x' axis of the printing area, determine the fiber printing paths of the area where the streamline does not intersect with the hole circumference, the area where the streamline intersects with the hole circumference, and the area where the streamline overlaps with the x' axis;

[0016] Step 6: Based on the fiber printing path in the upper half plane of the x' axis of the printing area, the fiber printing path in the lower half plane of the x' axis of the printing area is obtained symmetrically with the origin.

[0017] Optionally, in the above-mentioned composite material perforated plate continuous fiber 3D printing path planning method, step 1 includes:

[0018] ;

[0019] in, Reserve machining allowance around the perforated plate.

[0020] Optionally, in the above-mentioned composite material perforated plate continuous fiber 3D printing path planning method, a processing allowance is reserved around the perforated plate. Take 20mm.

[0021] Optionally, in the above-mentioned composite material perforated plate continuous fiber 3D printing path planning method, step 4 is specifically as follows:

[0022] Calculate the global coordinate system The upper left corner of the lower print area , in the local coordinate system The position constant of the streamline is :

[0023] ;

[0024] Calculate local coordinate system Coordinates of the tangent point between the lower streamline and the hole The position constant of the streamline :

[0025] ;

[0026] Calculate local coordinate system Lower origin coordinates The position constant of the streamline :

[0027] ;

[0028] Streamline position constant ,exist The area is the area where the streamlines do not intersect the hole; The area is the intersection area between the streamline and the hole; The area where the streamlines coincide with the x' axis;

[0029] Among them, the local coordinate system The global coordinate system The rotation angle is the deflection angle in the fiber trajectory parameter. .

[0030] Optionally, in the above-mentioned method for planning the continuous fiber 3D printing path of the composite material perforated plate, in step 5, determining the fiber printing path of the area where the streamline does not intersect the hole circumference on the upper half plane of the x' axis of the printing area includes:

[0031] S511, take the position constant of the first streamline as , write the first streamline equation;

[0032] S512: Determine the horizontal coordinate interval of the first streamline equation passing through the printing area ;

[0033] S513, the horizontal coordinate interval of the first streamline Equally divided, the interval between equal divisions should not be greater than the minimum printing distance , get the horizontal coordinate of the first streamline, and then get the vertical coordinate of the first streamline, generate the coordinate of the first streamline, and get the fiber printing path of the first streamline, which is specifically:

[0034] calculate ;

[0035] in, is the horizontal coordinate interval of the first streamline The number of equal points of ; is the floor rounding function; is the horizontal coordinate interval of the first streamline of equal intervals;

[0036] Calculate the horizontal coordinate of the first streamline:

[0037] ;

[0038] Substitute the abscissa of the first streamline into the equation of the first streamline to obtain the ordinate of the first streamline;

[0039] Add the abscissa of the first streamline to the abscissa sequence of the fiber printing path , and add the ordinate of the first streamline to the ordinate sequence of the fiber printing path ;

[0040] S514, Order =0, =1;

[0041] S515, calculate the The position constant of the streamline ,in, is a constant increment for a specified position; if , then proceed to S516, if , then the process is terminated;

[0042] S516, calculate the The flow line and Minimum distance between streamlines ;like , then proceed to S517, if , then Add 1 to the value and return to S515;

[0043] S517, take The position constant of the streamline , write the first Streamline equations;

[0044] S518, determine The horizontal coordinate interval of the streamline equation passing through the printing area ;

[0045] S519, The horizontal coordinate interval of the streamline Equally divided, the interval between equal divisions should not be greater than the minimum printing distance , get the The horizontal coordinate of the first streamline is obtained The vertical coordinate of the streamline generates the The coordinates of the streamlines are obtained The fiber printing path of the streamline is as follows:

[0046] calculate ;

[0047] in, For the The horizontal coordinate interval of the streamline The number of equal points of ; For the The horizontal coordinate interval of the streamline of equal intervals;

[0048] Calculate the The horizontal coordinate of the streamline:

[0049] ;

[0050] For the The last coordinate point of the streamline is in the horizontal coordinate sequence of the fiber printing path The footer in the middle;

[0051] ;

[0052] in, For the The horizontal coordinate interval of the streamline The number of equal points of ;

[0053] The first Substitute the horizontal coordinate of the streamline into the The streamline equation is The ordinate of the streamline;

[0054] The first The horizontal coordinate of the streamline is added to the horizontal coordinate sequence of the fiber printing path , and the The ordinate of the flow line is added to the ordinate sequence of the fiber printing path ;

[0055] S519, will The value of is increased by 1, and the result is returned to S514.

[0056] Optionally, in the above-mentioned composite material perforated plate continuous fiber 3D printing path planning method, the streamlines in the area where the half-plane streamlines on the x' axis do not intersect with the hole periphery are recorded as Article 1 The position constant of the streamline is , the last coordinate point in the abscissa sequence of the fiber printing path The footer in the :

[0057] ;

[0058] In step 5, for the upper half plane of the x' axis of the printing area, the fiber printing path in the area where the streamline intersects the hole circumference is determined, including:

[0059] S521. Calculate the number of streamlines in the area where the streamlines intersect the hole perimeter and interval :

[0060] ;

[0061] S522, Order ;

[0062] S523, take The position constant of the streamline , write the first Streamline equations;

[0063] S524, determine The horizontal coordinate interval of the streamline equation passing through the printing area ;

[0064] S525, the The horizontal coordinate interval of the streamline Equally divided, the interval between equal divisions should not be greater than the minimum printing distance , get the The horizontal coordinate of the first streamline is obtained The vertical coordinate of the streamline generates the The coordinates of the streamlines are obtained The fiber printing path of the streamline is as follows:

[0065] calculate ;

[0066] in, For the The horizontal coordinate interval of the streamline The number of equal points of ; For the The horizontal coordinate interval of the streamline of equal intervals;

[0067] No. The last coordinate point of the streamline is in the horizontal coordinate sequence of the fiber printing path The footer in the ,according to The positive and negative of The horizontal coordinate of the streamline;

[0068] The first Substitute the horizontal coordinate of the streamline into the The streamline equation is The ordinate of the streamline;

[0069] Will In the coordinates of the streamline, the part inside the hole is deleted;

[0070] The first The horizontal coordinate of the streamline is added to the horizontal coordinate sequence of the fiber printing path , and the The ordinate of the flow line is added to the ordinate sequence of the fiber printing path ;

[0071] S525, if , then let Add 1 and return to S523.

[0072] Optionally, in the above-mentioned composite material perforated plate continuous fiber 3D printing path planning method, the streamlines in the half plane on the x' axis that do not intersect with the hole circumference and the streamlines in the area intersecting with the hole circumference have a total of Bar, the last point in the abscissa sequence of the fiber printing path The footer in the ;

[0073] In step 5, for the upper half plane of the x' axis of the printing area, the fiber printing path in the area where the streamline coincides with the x' axis is determined, including:

[0074] S531, take The position constant of the streamline , write the first Streamline equations;

[0075] S532, determine The horizontal coordinate interval of the streamline equation passing through the printing area ;

[0076] S533, the The horizontal coordinate interval of the streamline Equally divided, the interval between equal divisions should not be greater than the minimum printing distance , get the The horizontal coordinate of the first streamline is obtained The ordinate of the first streamline generates the coordinate of the first streamline, and the The fiber printing path of the streamline is as follows:

[0077] calculate ;

[0078] in, For the The horizontal coordinate interval of the streamline The number of equal points of ; For the The horizontal coordinate interval of the streamline of equal intervals;

[0079] Calculate the The horizontal coordinate of the streamline:

[0080] ;

[0081] The first Substitute the horizontal coordinate of the streamline into the The streamline equation is The ordinate of the streamline;

[0082] The first The horizontal coordinate of the streamline is added to the horizontal coordinate sequence of the fiber printing path , and the The ordinate of the flow line is added to the ordinate sequence of the fiber printing path .

[0083] Optionally, in the above-mentioned composite material perforated plate continuous fiber 3D printing path planning method, the minimum printing distance Take 1mm.

[0084] This application has at least the following beneficial technical effects:

[0085] A method for planning the continuous fiber 3D printing path of a composite material perforated plate is provided. For the perforated plate optimized based on the streamline equation of flow around an ideal fluid cylinder, the fiber printing path is planned so that the fiber printing path is continuous and the fiber printing path spacing is as small as possible on the basis of ensuring the minimum printing spacing, thereby meeting the manufacturing feasibility requirements and fully improving the mechanical properties of the perforated plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 Schematic diagram of an orifice plate optimized based on a streamline equation for flow around an ideal fluid cylinder provided in an embodiment of the present application;

[0087] Figure 2 is a schematic diagram of the size of the perforated plate provided in the embodiment of the present application;

[0088] Figure 3 It is a schematic diagram of a continuous fiber 3D printing path planning method for a composite material perforated plate provided in an embodiment of the present application;

[0089] Figure 4 This is a schematic diagram of the continuous fiber printing path of the first layer of the composite material perforated plate provided in an embodiment of the present application;

[0090] Figure 5 This is a schematic diagram of the continuous fiber printing path of the second layer of the composite material perforated plate provided in an embodiment of the present application;

[0091] Figure 6It is a schematic diagram of the continuous fiber printing path of the third layer of the composite material perforated plate provided in an embodiment of the present application.

[0092] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be construed as limitations on the present application. DETAILED DESCRIPTION

[0093] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0094] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the usual meanings understood by those of ordinary skill in the art to which this application belongs. The words used in the description of this application to indicate orientation are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application indicates that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0095] A method for planning continuous fiber 3D printing path for a composite material perforated plate is disclosed. For a perforated plate that is optimized based on the streamline equation of flow around an ideal fluid cylinder, a fiber printing path is planned so that the fiber printing path is continuous and the fiber printing path spacing is as small as possible while ensuring a minimum printing spacing, thereby meeting the manufacturing feasibility requirements and fully improving the mechanical properties of the perforated plate.

[0096] The perforated plate is optimized based on the streamline equation of the ideal fluid flow around a cylinder, such as Figure 1 As shown in the figure, the streamline cluster of the ideal fluid flowing around the cylinder, the uniform streamline flow velocity direction is along Axis direction, in The streamline equation in the local coordinate system is as follows:

[0097] ………… (1)

[0098] in, is the stream function; To control the parameters, the shape of the streamlines is determined; is the position constant, which determines the position of the streamline.

[0099] Local Coordinate System From the global coordinate system Rotated, for any point P, in the global coordinate system The lower coordinates are , local coordinate system The coordinates below are , and their mutual transformation relationship is as follows:

[0100] …………(2)

[0101] in, for Axis and The angle of the axis.

[0102] For Figure 2 The perforated plate shown, when the length is given ,width , center hole diameter , Number of layers , material properties, loads and boundary conditions of the perforated plate, the streamline shape of each single layer controls the parameters and deflection angle is the design variable ( The fiber trajectory parameters can be expressed as < | >), with the buckling load or failure load of the perforated plate To optimize the target, the mathematical model for optimization design is as follows:

[0103] ………… (3)

[0104] The above optimization design only obtains the fiber trajectory parameters of each single layer of the perforated plate. | >), further planning is needed to connect the flow lines together to form Figure 3 The continuous path shown in the figure meets the printing spacing requirements, please refer to the following for details.

[0105] For composite material perforated plate single layer, the input parameters include the length of the perforated plate ,width , center hole diameter , the fiber trajectory parameters obtained by optimization design < | >, and minimum print spacing .

[0106] Step 1: Based on the length of the perforated plate ,width , determine the print area size, including the print area length ,width .

[0107] 3D printing requires a processing allowance. After printing, the burrs around the edges are removed and the holes are machined.

[0108] The machining allowance is reserved around the opening plate. , then determine the print area size as follows:

[0109] …………(4)

[0110] Figure 3 The area inside the middle inner rectangular frame is the size of the perforated plate, and the area inside the outer rectangular frame is the printing area.

[0111] Step 2: Take the uniform streamline flow direction as Axis direction, defining the local coordinate system .

[0112] Local Coordinate System The uniform streamline velocity direction is along The axis direction is determined by the global coordinate system Rotated, the rotation angle is the deflection angle in the fiber trajectory parameters .

[0113] Step 3: In the local coordinate system Next, determine the upper half plane of the x' axis of the printing area.

[0114] Step 4: Divide the upper half plane of the x' axis of the printing area into the area where the streamlines do not intersect with the hole circumference, the area where the streamlines intersect with the hole circumference, and the area where the streamlines overlap with the x' axis.

[0115] The streamline equation (1) is given by the position constant Control, solve each area below The value range of .

[0116] Global coordinate system The coordinates of the upper left corner of the lower print area are , according to formula (2) to transform to the local coordinate system Substituting into (1) we can get:

[0117] ………… (5)

[0118] in, The global coordinate system The upper left corner of the lower print area , in the local coordinate system Below, the position constant of the streamline.

[0119] The local coordinate system Coordinates of the tangent point between the lower streamline and the hole , origin coordinates Substituting into (1) we can get:

[0120] …………(6)

[0121] in, is the local coordinate system Coordinates of the tangent point between the lower streamline and the hole The position constant of the streamline; is the local coordinate system Lower origin coordinates The position constant of the streamline.

[0122] Therefore, when When , the streamline does not intersect the hole; when When , the streamline intersects the hole; when When , the streamlines coincide with the x' axis.

[0123] Step 5: According to the printing continuity and minimum printing spacing requirements, for the upper half plane of the x' axis of the printing area, determine the fiber printing paths of the areas where the streamlines do not intersect with the hole circumference, the areas where the streamlines intersect with the hole circumference, and the areas where the streamlines overlap with the x' axis.

[0124] S51. For the upper half plane of the x' axis of the printing area, determine the fiber printing path in the area where the streamline does not intersect with the hole circumference.

[0125] In the area where the streamlines do not intersect the hole circumference, the adjacent printing paths ( , ) is larger when it is far away from the hole, and the distance is larger when x'=0 Minimum:

[0126] …………(7)

[0127] S511, take the position constant of the first streamline as , write the first streamline equation.

[0128] To ensure that the streamline intersects the printed boundary, the position constant of the first streamline is taken as , so the first streamline equation can be written as:

[0129] …………(8)

[0130] S512: Determine the horizontal coordinate interval of the first streamline equation passing through the printing area .

[0131] The printing area boundaries are 4 straight lines, and the equations of the 4 straight lines are as follows:

[0132] …………(9)

[0133] Combining equations (8) and (9), we can obtain the horizontal coordinates of the first streamline and the left, right, top, and bottom boundaries of the printing area. ,but:

[0134] ………… (10)

[0135] S513, the horizontal coordinate interval of the first streamline Equally divided, the interval between equal divisions should not be greater than the minimum printing distance , get the horizontal coordinate of the first streamline, and then get the vertical coordinate of the first streamline, generate the coordinate of the first streamline, which is the fiber printing path of the first streamline.

[0136] …………(11)

[0137] in, is the horizontal coordinate interval of the first streamline The number of equal points of ; is the floor rounding function; is the horizontal coordinate interval of the first streamline of equal intervals.

[0138] The abscissa of the first streamline is calculated as follows:

[0139] …………(12)

[0140] Substituting the horizontal coordinate of the first streamline into equation (8) yields the vertical coordinate of the first streamline.

[0141] Add the abscissa of the first streamline to the abscissa sequence of the fiber printing path , and add the ordinate of the first streamline to the ordinate sequence of the fiber printing path .

[0142] S514, Order =0, =1.

[0143] S515, calculate the The position constant of the streamline ,in, is the specified position constant increment. The smaller the value, the slower the algorithm runs and the smaller the spacing of the generated paths away from the hole periphery.

[0144] like , then proceed to S516, if , then terminate the process.

[0145] S516. According to formula (7), calculate the The flow line and Minimum distance between streamlines ;

[0146] like , then proceed to S517, if , then The value of is increased by 1, and the result is returned to S515.

[0147] S517, take The position constant of the streamline , write the first Streamline equation:

[0148] …………(13)

[0149] S518, determine The horizontal coordinate interval of the streamline equation passing through the printing area .

[0150] Combining equations (9) and (13), we can obtain The horizontal coordinates of the flow line and the left, right, top, and bottom boundaries of the printing area ,but:

[0151] …………(14)

[0152] S519, The horizontal coordinate interval of the streamline Equally divided, the interval between equal divisions should not be greater than the minimum printing distance , get the The horizontal coordinate of the first streamline is obtained The vertical coordinate of the streamline generates the The coordinates of the first streamline are A streamlined fiber printing path.

[0153] ………… (15)

[0154] in, For the The horizontal coordinate interval of the streamline The number of equal points of ; For the The horizontal coordinate interval of the streamline of equal intervals.

[0155] No. The last coordinate point of the streamline is in the horizontal coordinate sequence of the fiber printing path The footer in the :

[0156] …………(16)

[0157] in, For the The horizontal coordinate interval of the streamline The number of equally divided points.

[0158] In order to connect adjacent printing paths end to end, The positive and negative of The horizontal coordinates of the streamlines are as follows:

[0159] …………(17)

[0160] The first Substituting the horizontal coordinate of the streamline into equation (14) we can get The vertical coordinate of the streamline.

[0161] The first The horizontal coordinate of the streamline is added to the horizontal coordinate sequence of the fiber printing path , and the The ordinate of the flow line is added to the ordinate sequence of the fiber printing path .

[0162] S519, will The value of is increased by 1, and the result is returned to S514.

[0163] The streamlines in the area where the streamlines in the half plane on the x' axis do not intersect with the circumference of the hole are recorded as Article 1 The position constant of the streamline is , the last coordinate point in the abscissa sequence of the fiber printing path The footer in the :

[0164] …………(18)

[0165] S52, for the upper half plane of the x' axis of the printing area, determine the fiber printing path in the area where the streamline intersects the hole circumference.

[0166] S521. Calculate the number of streamlines in the area where the streamlines intersect the hole perimeter and interval .

[0167] In the area where the streamlines intersect the hole circumference, the distance between adjacent printing paths is smaller when they are far away from the hole circumference, and larger near the hole circumference. The distance between adjacent printing paths in the far field is approximately equal to the position constant. The difference is therefore the position constant in this region The values ​​can be taken arithmetic differences. At the same time, in order to ensure the distance from the x' axis, the number of streamlines in this area and interval The calculation is as follows:

[0168] …………(19)

[0169] S522, Order …………(20)

[0170] S523, take The position constant of the streamline , write the first Streamline equation:

[0171] …………(twenty one)

[0172] S524, determine The horizontal coordinate interval of the streamline equation passing through the printing area .

[0173] Combining equations (9) and (21), we can obtain Streamline and the horizontal coordinates of the left, right, top, and bottom boundaries of the printing area ,but:

[0174] …………(twenty two)

[0175] S525, the The horizontal coordinate interval of the streamline Equally divided, the interval between equal divisions should not be greater than the minimum printing distance , get the The horizontal coordinate of the first streamline is obtained The vertical coordinate of the streamline generates the The coordinates of the first streamline are A streamlined fiber printing path.

[0176] …………(twenty three)

[0177] in, For the The horizontal coordinate interval of the streamline The number of equal points of ; For the The horizontal coordinate interval of the streamline of equal intervals.

[0178] No. The last coordinate point of the streamline is in the horizontal coordinate sequence of the fiber printing path The footer in the In order to connect adjacent printing paths end to end, according to The positive and negative of The horizontal coordinate of the streamline;

[0179] The first Substituting the horizontal coordinate of the streamline into equation (21) yields The ordinate of the streamline;

[0180] Will In the coordinates of the streamline, the part inside the hole is deleted;

[0181] The first The horizontal coordinate of the streamline is added to the horizontal coordinate sequence of the fiber printing path , and the The ordinate of the flow line is added to the ordinate sequence of the fiber printing path , for this, the algorithm can be designed as follows:

[0182] Step 1: Order …………(twenty four)

[0183] Step 2: Calculation The horizontal coordinate of the streamline:

[0184] …………(25)

[0185] Will Substitute the horizontal coordinate of the streamline into equation (21) to obtain the corresponding vertical coordinate .

[0186] Step 3: If you click Satisfy the equation , then the point is inside the hole and proceed to step 4. Otherwise, update the path coordinate sequence:

[0187] …………(26)

[0188] Step 4: If , then let Add 1 and return to step 2, otherwise, proceed to step 5;

[0189] Step 5: End and Update .

[0190] S525, if , then let Add 1 and return to S523.

[0191] The streamlines in the area where the streamlines in the half plane on the x' axis do not intersect with the hole circumference and the streamlines in the area where the streamlines intersect with the hole circumference have a total of Bar, the last point in the abscissa sequence of the fiber printing path The footer in the .

[0192] S53. For the upper half plane of the x' axis of the printing area, determine the fiber printing path in the area where the streamline coincides with the x' axis.

[0193] There is only one streamline that coincides with the x' axis in the region where the streamline coincides with the x' axis, which is streamlines, corresponding to the position constant .

[0194] S531, take The position constant of the streamline , write the first Streamline equation:

[0195] …………(27)

[0196] S532, determine The horizontal coordinate interval of the streamline equation passing through the printing area .

[0197] Combining equations (9) and (27), we can obtain Streamline and the horizontal coordinates of the left, right, top, and bottom boundaries of the printing area ,but:

[0198] ………(28)

[0199] S533, the The horizontal coordinate interval of the streamline Equally divided, the interval between equal divisions should not be greater than the minimum printing distance , get the The horizontal coordinate of the first streamline is obtained The ordinate of the first streamline generates the coordinate of the first streamline, which is the first A streamlined fiber printing path.

[0200] …………(29)

[0201] in, For the The horizontal coordinate interval of the streamline The number of equal points of ; For the The horizontal coordinate interval of the streamline of equal intervals.

[0202] In order to connect adjacent printing paths end to end, The positive and negative of The horizontal coordinate of the streamline:

[0203] …………(30)

[0204] The first Substituting the horizontal coordinate of the streamline into equation (27) yields The vertical coordinate of the streamline.

[0205] The first The horizontal coordinate of the streamline is added to the horizontal coordinate sequence of the fiber printing path , and the The ordinate of the flow line is added to the ordinate sequence of the fiber printing path .

[0206] Step 6: Based on the fiber printing path in the upper half plane of the x' axis of the printing area, the fiber printing path in the lower half plane of the x' axis of the printing area is obtained symmetrically with the origin.

[0207] It can be observed that the fiber printing path in the upper half plane of the x' axis and the fiber printing path in the lower half plane of the x' axis are symmetrical about the origin. Therefore, after the fiber printing path in the upper half plane of the x' axis is determined, the fiber printing path in the lower half plane of the x' axis can be directly given according to the symmetry. At this time, the abscissa sequence of the fiber printing path is , Fiber printing path ordinate sequence Add the following:

[0208] …………(31)

[0209] The method for planning the continuous fiber 3D printing path of a composite material perforated plate disclosed in the above-mentioned embodiment plans the fiber printing path for the perforated plate optimized based on the streamline equation of the ideal fluid flow around a circular cylinder, so that the fiber printing path is continuous and meets the minimum printing spacing requirement, thereby ensuring the surface quality of the perforated plate and meeting the manufacturing feasibility requirements. On this basis, the maximum distance of the fiber path is made as small as possible, thereby ensuring the fiber volume content, thereby fully improving the mechanical properties of the perforated plate.

[0210] In a specific example, the composite opening plate size =150mm, =100mm, =20mm, symmetrical ply, total number of plies is 6, single layer thickness is set to 0.155mm, material performance parameters are set to longitudinal modulus 118GPa, transverse modulus 8980MPa, shear modulus 4210 MPa, in-plane Poisson's ratio 0.306; load boundary conditions are: simply supported boundary conditions are applied to the upper and lower sides, the left and right loading edges are set to fixed support boundary conditions, and a 1000N compressive load is applied to the right loading edge.

[0211] The number of independent single layers of the symmetrically laid laminate is half of the number of layers, so N = 3. Set the laying trajectory parameter range: The multi-island genetic algorithm provided by the optimization software Isight was combined with ABAQUS for simulation to solve equation (3). The fiber placement trajectory parameters for the optimized design of the perforated plate obtained by iterative calculation were: [<139|32°> / <147|38°> / <134|39°>].

[0212] Set the minimum printing distance , the processing allowance reserved around the composite material opening plate is , specify the position constant increment as , the continuous fiber 3D printing path planning method for composite material perforated plate disclosed in the above embodiment is used to plan the continuous fiber 3D printing path, and the continuous fiber path curve of each single layer is drawn. The results are shown in Figure 4~Figure 6 .

[0213] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A method for planning the path of continuous fiber 3D printing of composite material perforated plate, characterized in that: include: Step 1: Based on the length a and width b of the perforated plate, determine the size of the printing area, including the length A and width B of the printing area; Step 2: Taking the direction of uniform streamline flow velocity as the x'-axis direction, define the local coordinate system x'oy', and the origin of the local coordinate system x'oy' is at the midpoint of the perforated plate; Step 3: In the local coordinate system x'oy', determine the upper half plane of the x' axis of the printing area; Step 4: Divide the upper half plane of the x' axis of the printing area into the area where the streamline does not intersect with the hole circumference, the area where the streamline intersects with the hole circumference, and the area where the streamline coincides with the x' axis; Step 5: According to the printing continuity and the minimum printing spacing requirements, for the upper half plane of the x' axis of the printing area, the fiber printing paths of the area where the streamline does not intersect with the hole circumference, the area where the streamline intersects with the hole circumference, and the area where the streamline overlaps with the x' axis are determined in sequence; Step 6: Based on the fiber printing path in the upper half plane of the x' axis of the printing area, the fiber printing path in the lower half plane of the x' axis of the printing area is obtained symmetrically with the origin; Step 4 is as follows: Calculate the upper left corner of the printing area under the overall coordinate system xoy In the local coordinate system x'oy', the position constant C of the streamline is 1 : Calculate the coordinates of the point of tangency between the streamline and the hole in the local coordinate system x'oy' The position constant C of the streamline 2 : Calculate the position constant C of the streamline at the origin coordinate (0, 0) in the local coordinate system x'oy' 3 : C 3 ＝0； With streamline position constant C, at C 1 >C>C 2 The area is the area where the streamline does not intersect with the hole; 2 The area where C>0 is the intersection area between the streamline and the hole; 3 = 0, as the area where the streamline coincides with the x' axis; The local coordinate system x'oy' can be obtained by rotating the global coordinate system xoy, and the rotation angle is the deflection angle θ in the fiber trajectory parameter. k ; Γ k is the streamline shape control parameter, and D is the central hole diameter of the perforated plate.

2. The method for continuous fiber 3D printing path planning of composite material perforated plate according to claim 1, characterized in that: In step one, there are: A=a+2Δl,B=b+2Δl; Among them, Δl is the machining allowance reserved around the perforated plate.

3. The method for 3D printing path planning of composite material perforated plate continuous fiber according to claim 2, characterized in that: The reserved machining allowance Δl around the perforated plate is 20mm.

4. The method for continuous fiber 3D printing path planning of composite material perforated plate according to claim 3, characterized in that: In step 5, for the upper half plane of the x' axis of the printing area, the fiber printing path in the area where the streamline does not intersect with the hole circumference is determined, including: S511, take the position constant of the first streamline as C1=C 1 -d min , write the first streamline equation; S512: Determine the horizontal coordinate interval of the first streamline equation passing through the printing area S513, the horizontal coordinate interval of the first streamline Equally divided, the interval between equal divisions is no greater than the minimum printing distance d min , get the horizontal coordinate of the first streamline, and then get the vertical coordinate of the first streamline, generate the coordinate of the first streamline, and get the fiber printing path of the first streamline, which is specifically: calculate Where N1 is the horizontal coordinate interval of the first streamline The number of equally divided points; floor is the floor rounding function; Δx1 is the horizontal coordinate interval of the first streamline of equal intervals; Calculate the horizontal coordinate of the first streamline: j=i+1,i=0,1,2,…N1; Substitute the abscissa of the first streamline into the equation of the first streamline to obtain the ordinate of the first streamline; Add the abscissa of the first streamline to the abscissa sequence of the fiber printing path X' = {X j '}, and add the ordinate of the first streamline to the ordinate sequence of the fiber printing path Y'={Y j '}; S514, set K=0, n=1; S515. Calculate the position constant C of the n+1th streamline n+1 =C n -d min -KΔC, where ΔC is the constant increment of the specified position; if C n+1 ≥C 2 , then proceed to S516, if C n+1 <C 2 , then the process is terminated; S516. Calculate the minimum distance d between the n+1th streamline and the nth streamline n If d n ≥d min , then proceed to S517, if d n <d min , then add 1 to the value of K and return to S515; S517, take the position constant C of the n+1th streamline n+1 =C n -d min -KΔC, write the equation of the n+1th streamline; S518: Determine the horizontal coordinate interval where the n+1th streamline equation passes through the printing area S519, the horizontal coordinate interval of the n+1th streamline Equally divided, the interval between equal divisions is no greater than the minimum printing distance d min , get the horizontal coordinate of the n+1th streamline, and then get the vertical coordinate of the n+1th streamline, generate the coordinate of the n+1th streamline, and get the fiber printing path of the n+1th streamline, which is specifically: calculate Among them, N n+1 is the horizontal coordinate interval of the n+1th streamline The number of equally divided points; Δx n+1 is the horizontal coordinate interval of the n+1th streamline of equal intervals; Calculate the horizontal coordinate of the n+1th streamline: j=J n +i+1,i=0,1,2,…N n+1 ; J n The last coordinate point of the nth streamline in the fiber printing path is the horizontal coordinate sequence X'={X j '}'s subscript; Among them, Ni is the horizontal coordinate interval of the i-th streamline The number of equal points of ; Substitute the horizontal coordinate of the n+1th streamline into the n+1th streamline equation to obtain the vertical coordinate of the n+1th streamline; Add the horizontal coordinate of the n+1th streamline to the fiber printing path horizontal coordinate sequence X'={X j '}, and add the ordinate of the n+1th streamline to the fiber printing path ordinate sequence Y'={Y j '}; S519. Add 1 to the value of n, and return to S514.

5. The method for continuous fiber 3D printing path planning of composite material perforated plate according to claim 4, characterized in that: The streamlines in the area where the half-plane streamlines on the x' axis do not intersect with the hole circumference are recorded as n0, and the position constant of the n0th streamline is The last coordinate point in the fiber printing path horizontal coordinate sequence X' = {X j '}'s footer is In step 5, for the upper half plane of the x' axis of the printing area, the fiber printing path in the intersection area of ​​the streamline and the hole circumference is determined, including: S521, calculate the number of streamlines m0 and the interval ΔC in the area where the streamlines intersect the hole m : S522, let m=0, S523, take the position constant of the n0+m+1th streamline Write down the equation of the n0+m+1th streamline; S524: Determine the horizontal coordinate interval where the n0+m+1th streamline equation passes through the printing area S525, set the horizontal coordinate interval of the n0+m+1th streamline Equally divided, the interval between equal divisions is no greater than the minimum printing distance d min , get the horizontal coordinate of the n0+m+1th streamline, and then get the vertical coordinate of the n0+m+1th streamline, generate the coordinate of the n0+m+1th streamline, and get the fiber printing path of the n0+m+1th streamline, which is specifically: calculate in, is the horizontal coordinate interval of the n0+m+1th streamline The number of equal points of ; is the horizontal coordinate interval of the n0+m+1th streamline of equal intervals; The last coordinate point of the n0+mth streamline is in the abscissa sequence of the fiber printing path X'={X j '}'s footer is according to The positive and negative value of the streamline is used to calculate the horizontal coordinate of the n0+m+1th streamline; Substitute the horizontal coordinate of the n0+m+1th streamline into the equation of the n0+m+1th streamline to obtain the vertical coordinate of the n0+m+1th streamline; Delete the coordinates of n0+m+1 streamlines that are inside the hole; Add the horizontal coordinate of the n0+m+1th streamline to the fiber printing path horizontal coordinate sequence X'={X j '}, and add the ordinate of the n0+m+1th streamline to the fiber printing path ordinate sequence Y'={Y j '}; S525. If m<m0-1, add 1 to m and return to S523.

6. The method for continuous fiber 3D printing path planning of composite material perforated plate according to claim 5, characterized in that: There are n0+m0 streamlines in the area where the half-plane streamlines on the x' axis do not intersect with the hole circumference and the streamlines in the area where the streamlines intersect with the hole circumference. The last point is in the fiber printing path horizontal coordinate sequence X'={X j '}'s footer is In step 5, for the upper half plane of the x' axis of the printing area, the fiber printing path in the area where the streamline coincides with the x' axis is determined, including: S531, take the position constant of the n0+m0+1th streamline Write the equation of the n0+m0+1th streamline; S532: Determine the horizontal coordinate interval where the n0+m0+1th streamline equation passes through the printing area S533, the horizontal coordinate interval of the n0+m0+1th streamline Equally divided, the interval between equal divisions is no greater than the minimum printing distance d min , get the horizontal coordinate of the n0+m0+1th streamline, and then get the vertical coordinate of the n0+m0+1th streamline, generate the coordinate of the streamline, and get the fiber printing path of the n0+m0+1th streamline, which is specifically: calculate in, is the horizontal coordinate interval of the n0+m0+1th streamline The number of equal points of ; is the horizontal coordinate interval of the n0+m0+1th streamline of equal intervals; Calculate the horizontal coordinate of the n0+m0+1th streamline: Substitute the horizontal coordinate of the n0+m0+1th streamline into the equation of the n0+m0+1th streamline to obtain the vertical coordinate of the n0+m0+1th streamline; Add the horizontal coordinate of the n0+m0+1th streamline to the fiber printing path horizontal coordinate sequence X'={X j '}, and add the ordinate of the n0+m0+1th streamline to the fiber printing path ordinate sequence Y'={Y j '}.

7. The method for continuous fiber 3D printing path planning of composite material perforated plate according to claim 6, characterized in that: Minimum printing distance d min Take 1mm.

Images