A Structural Key Load Screening Method

Abstract

The present invention discloses a method for screening critical structural loads, comprising the following steps: S1. Obtaining result data for load operating points: Calculating all load conditions using an engineering method or a Gfem model to obtain load operating points and the results of the load operating point calculations; S2. Obtaining the structural loads of the structure under investigation at the load operating points: For the structure to be investigated, obtaining the structural loads from the calculation results in step S1, and determining values for bending, shear, torsion, and other structural loads based on actual conditions. The present invention forms a closed convex polygon based on the load data points. According to the properties of convex polygons, points within the convex polygon (including remaining vertices) are all located on the same side of the extension line of any side thereof. Based on the combined envelope, the critical load design condition can be ultimately selected, ensuring that severe load conditions are not omitted.

Description

Technical Field

[0001] The present invention relates to the technical field of computer simulation, in particular to a method for screening critical structural loads. Background Art

[0002] Aircraft structures are subject to a wide variety of loads during their service life. During structural design, load specialists must identify the conditions under which each component experiences maximum loads, along with the magnitude and distribution of these loads, from a complex set of load combinations. Typically, this involves a comprehensive approach of parameter analysis, design point selection, and parameter selection to initially determine loads. Finally, single-value and combined envelope methods are used to determine the final net component loads.

[0003] The current method is a combined envelope screening method. Drawing the load envelope is not equivalent to the load screening method, but is only the most important core of it. Summary of the Invention

[0004] The object of the present invention is to provide a method for screening critical loads of a structure, so as to solve the problem that load conditions are still omitted in the current method mentioned in the background art.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for screening critical loads of a structure, the method comprising the following steps:

[0006] S1. Obtaining the result data of the load condition point: Calculate all load conditions using engineering methods or the Gfem model to obtain the load condition point and the results of the load condition point calculation;

[0007] S2. Obtaining the structural load of the structure under investigation at the load condition point: For the structure to be investigated, obtain the structural load calculated in step S1, and determine the values of the structural loads such as bending, shear, and torsion according to the actual situation;

[0008] S3. Set the structural load type to be examined, such as a combination of bending, shear, and torsion: the user selects the load type of the structure to be examined, and the method assigns the coordinate value of the load point according to the user's selection;

[0009] S4. Generate data points with N-dimensional coordinates to form a data point cloud. The load points generated in step 3 are converted into a point cloud with N-dimensional coordinates, where N is the load type selected by the user. For example, if the user selects bending or shear, N=2; if the user selects bending, shear, and torsion, N=3. Generally, in engineering, N is 2 or 3, but in this method, N can be any positive integer greater than 2.

[0010] S5. Call the N-Dim-ConvexHull core calculation program for the N-dimensional point cloud convex hull: The core calculation N-Dim-ConvexHull takes a point cloud as input and outputs a convex hull composed of some points. This convex hull ensures that all other load points are contained "inside" the convex hull. For the two-dimensional case, all load points on the plane are contained in the closed curve composed of two-dimensional discrete points. For the three-dimensional case, all load points in space are contained in the closed surface composed of three-dimensional discrete points. For the N-dimensional case, all load points in the N-dimensional Euclidean space are contained in the N-1-dimensional closed structure composed of N-dimensional discrete points.

[0011] S6. Obtain the convex hull of N-Dim and record the load point numbers on the convex hull. After obtaining the convex hull, it is necessary to record the load point numbers on the convex hull to facilitate outputting the corresponding structural loads.

[0012] S7. Output the filtered structural load: output the structural load data in step 6 in text form.

[0013] Preferably, the method for calculating the convex hull of the core comprises the following steps:

[0014] 101. Select the maximum value point A and the minimum value point B under the x coordinate by sorting;

[0015] 102. Through point A and point B, a straight line can be determined to divide the point cloud into U AB and D AB Two sub-point clouds;

[0016] 103. In parallel, find the point C farthest from the line AB in the two sub-point clouds to form triangle ABC;

[0017] 104. Points inside triangle ABC cannot be points on the convex hull, so these points will not be considered in subsequent calculations.

[0018] 105. Repeat steps 3 and 4 for the sides AC and AB of the triangle until no point in the sub-point cloud is outside any straight line.

[0019] 106, merge 102 U AB and D AB The convex hull of the point cloud forms the convex hull of the overall point cloud.

[0020] Preferably, the graphical display data of the method is performed using matlibplot.

[0021] Preferably, the N-dimensional point cloud information is read through a built-in function provided by the method.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention forms a closed convex polygon based on the load data points. According to the properties of convex polygons, the points inside the convex polygon (including the remaining vertices) are all located on the same side of the extension line of any side of the convex polygon. Based on the combined envelope, the critical load design condition can be finally selected to ensure that severe load conditions are not missed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a flow chart of the present invention;

[0025] Figure 2 This is a flowchart of the core algorithm for calculating the N-Dim-Convexhull of an N-dimensional point cloud. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0027] like Figure 1 As shown, an embodiment of the present invention discloses a method for screening critical loads of a structure, the method comprising:

[0028] 201. Obtain the result data of the load condition points through the input file, apply loads to the finite element model through each loading joint, and draw a force flow diagram; analyze the load conditions of each typical area based on the force flow diagram, and calculate the joint loads of the corresponding typical area;

[0029] 202. The structural load of the structure under the load condition point should be obtained through the program;

[0030] 203. Set the structural load type to be examined through the interactive interface, such as bending, shear, torsion, etc.

[0031] 204. Generate data points with N-dimensional coordinates through a built-in procedure of the method to form a data point cloud;

[0032] 205. Calculation is performed by calling the built-in N-dimensional point cloud convex hull core calculation program N-Dim-ConvexHull of the method;

[0033] 206. Obtain the convex hull of N-Dim through the built-in procedure of the method and record the load point number on the convex hull;

[0034] 207. Output the filtered structural loads through the file output function provided by the user interface.

[0035] The present invention is developed using Python, Matlibplot for data graphical display, and a graphical interface developed based on wxPython, providing convenient text input and text content display windows, and an easy-to-use graphical interactive interface. Users can complete the entire optimization solution process through the graphical interface provided by this method.

[0036] like Figure 2 As shown, the core calculation program N-Dim-ConvexHull calculates the convex hull of an N-dimensional point cloud through a recursive algorithm. The embodiment of the present invention discloses an N-Dim-ConvexHull method, which includes:

[0037] 301. Read N-dimensional point cloud information through the built-in function provided by the method;

[0038] 302. Sort the input point cloud using the built-in function provided by the method;

[0039] 303. Select N-1 data points through the built-in function provided by the method to form an N-1-dimensional segmentation structure;

[0040] 304. Split the point cloud into two sub-point clouds according to the N-1 dimensional segmentation structure using the built-in function provided by the method;

[0041] 305. Select the point farthest from the segmentation structure in the sub-point cloud through the built-in function provided by the method, and form an N-dimensional closed structure with the N-1-dimensional segmentation structure;

[0042] 306. The point cloud is divided into points inside the closed structure and points outside the closed structure through the built-in function provided by the method. The internal points can be ignored in subsequent calculations;

[0043] 307. Recursively perform steps 305 and 306 on each new N-1-dimensional segmentation structure of the N-dimensional closed structure using the built-in function provided by the method until no external points exist in the sub-point cloud, thereby obtaining the convex hull of the sub-point cloud;

[0044] 308. The N-dimensional closed solution structure of the two sub-point clouds is merged through the built-in function provided by the method to form the final solved convex hull.

[0045] In summary, the present invention forms a closed convex polygon based on the load data points. According to the properties of convex polygons, the points inside the convex polygon (including the remaining vertices) are all located on the same side of the extension line of any side of the polygon. Based on the combined envelope, the critical load design condition can be finally selected to ensure that severe load conditions are not missed.

[0046] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for screening critical structural loads, characterized by: The method comprises the following steps: S1. Obtaining the result data of the load condition point: Calculate all load conditions using engineering methods or the Gfem model to obtain the load condition point and the results of the load condition point calculation; S2. Obtain the structural load of the structure under investigation at the load condition point: For the structure to be investigated, obtain the structural load calculated in step S1, and determine the values of the bending, shear, and torsion structural loads according to the actual situation; S3. Set the structural load type to be examined. The user selects the load type of the structure to be examined and assigns the coordinate value of the load point according to the user's selection. S4. Generate data points with N-dimensional coordinates to form a data point cloud. The load points formed in step 3 are converted into a point cloud with N-dimensional coordinates, where N is the load type selected by the user. For example, if the user selects bending or shear, N=2; if the user selects bending, shear, and torsion, N=3. N is any positive integer greater than or equal to 2. S5. Call the N-Dim-ConvexHull core calculation program for the N-dimensional point cloud convex hull: The core calculation N-Dim-ConvexHull takes a point cloud as input and outputs a convex hull composed of some points. This convex hull ensures that all other load points are "inside" the convex hull. For the two-dimensional case, all load points on the plane are contained in the closed curve composed of the two-dimensional discrete points. For the three-dimensional case, all load points in space are contained in the closed surface composed of the three-dimensional discrete points. For the N-dimensional case, all load points in the N-dimensional Euclidean space are contained in the N-1-dimensional closed structure composed of the N-dimensional discrete points. S6. Obtain the convex hull of N-Dim and record the load point numbers on the convex hull. After obtaining the convex hull, record the load point numbers on the convex hull and output the corresponding structural loads. S7. Output the filtered structural load: Output the structural load data in step 6 in text form.

101. Select the maximum value point A and the minimum value point B under the x coordinate by sorting; 102. Through point A and point B, a straight line can be determined to divide the point cloud into U AB and D AB Two sub-point clouds; 103. Find the point C farthest from the line AB in the two sub-point clouds to form triangle ABC; 104. Points inside triangle ABC that are not on the convex hull are not considered in subsequent calculations.

105. Repeat steps 3 and 4 for the sides AC and AB of the triangle until no point in the sub-point cloud is outside any straight line. 106, merge 102 U AB and D AB The convex hull of the point cloud forms the convex hull of the overall point cloud.

2. A structural critical load screening method according to claim 1, characterized in that: Graphical display of data was performed using matlibplot.

3. A structural critical load screening method according to claim 2, characterized in that: Read N-dimensional point cloud information through built-in functions.

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