A method for restraining process deformation of elastic thin-walled stiffened plate

Abstract

The present application relates to the field of hull thin-walled stiffened plate processing and manufacturing, and particularly relates to a method for inhibiting process deformation of elastic thin-walled stiffened plate, comprising the following steps: selecting a steel plate with a thickness of 8 times of a target thickness; performing fine processing on a bottom plate of the stiffened plate; performing fine processing on an upper assembly of the stiffened plate; welding the bottom plate and the upper assembly to form the stiffened plate; milling and grinding an edge fixed area of the stiffened plate; and performing ultrasonic thickness measurement and surface flatness scanning measurement on a panel area of the stiffened plate. The method effectively inhibits welding and milling deformation of the elastic thin-walled stiffened plate, is of great significance for process flow optimization and fine processing, greatly improves the precision of local hydroelasticity test of the ship, and meets the technical requirements of the test.

Description

Technical Field

[0001] This invention relates to the field of ship hull thin-walled stiffening plate processing and manufacturing, and particularly to a method for suppressing deformation during the process of elastic thin-walled stiffening plate manufacturing. Background Technology

[0002] The increasing size of modern ships and the use of high-strength steel have led to thinner hull stiffeners, resulting in a softer hull structure. This results in significant elastic effects under wave excitation, posing a more severe challenge to structural strength and safety. During the segmented manufacturing of the hull, the thinner plates are highly susceptible to localized and overall deformation during processing. Furthermore, for scaled-down ship models, the precise machining and deformation suppression of the elastic thin-walled stiffeners directly impact the accuracy of towing tank test results. Therefore, elastic thin-walled stiffeners with minimal deformation are crucial for analyzing the surface load evolution characteristics and structural response characteristics of the hull.

[0003] Currently, in the fabrication of elastic stiffening plates in scaled-down ship models, thicker steel is typically used to suppress process deformation. However, this results in experimental results that cannot be truly equivalent to actual ship hull plates, leading to inaccurate results. Furthermore, there are few reports on process methods that truly consider the hydroelastic effect to suppress deformation of elastic thin-walled stiffening plates. According to the theory of calculating the stiffness of local small deformations of the hull and the calculation method of the hydroelastic effect coefficient, the elastic thin-walled stiffening plates used in current experiments are mostly simplified and cannot truly meet the experimental requirements.

[0004] Therefore, when comprehensively considering the mapping between the local hydroelastic effect of the hull and the actual thickness of the ship plate, how to establish a deformation suppression method for the processing of elastic thin-walled stiffened plates to meet the requirements of experimental technology and accuracy is the current challenge and focus of ship hydroelasticity testing technology. Summary of the Invention

[0005] Therefore, one objective of this invention is to propose a method for suppressing the deformation of elastic thin-walled stiffened plates during processing. This method can effectively suppress the deformation of thin-walled stiffened plates during processing and greatly improve the accuracy of scaled-down model tests of hulls.

[0006] To achieve the above objectives, one embodiment of the present invention proposes a method for suppressing deformation in the process of elastic thin-walled stiffened plates, comprising the following steps: Step S1, selecting a steel template with a thickness 8 times that of the target thickness; Step S2, finely processing the stiffened plate base plate; Step S3, finely processing the stiffened plate upper component; Step S4, welding the stiffened plate base plate and the stiffened plate upper component to form a test plate; Step S5, smoothing the front and back surfaces of the test plate; Step S6, milling the edge fixing area of ​​the stiffened plate; Step S7, performing ultrasonic thickness measurement and surface flatness scanning measurement on the stiffened plate grid area.

[0007] In addition, the method for suppressing process deformation of elastic thin-walled stiffened plates according to the above embodiments of the present invention may also have the following additional technical features:

[0008] Furthermore, in one embodiment of the present invention, the fine processing of the stiffened plate base plate in step S2 specifically includes: step S201, cutting and milling the steel jig to the length and width dimensions of the target test plate on a milling machine, while keeping the plate thickness unchanged; step S202, smoothing the front and back surfaces of the cut and milled plate on a surface grinder, removing 0.5mm from each surface to ensure a smooth and flat surface; step S203, engraving the plate grid and rib base on a CNC machine tool to obtain the test plate base plate.

[0009] Furthermore, in one embodiment of the present invention, the fine processing of the upper component of the stiffened plate in step S3 specifically includes: step S301, processing the upper edge frame of the plate and the upper section of the stiffener separately to the target size, with the upper section of the stiffener having the same thickness as the base of the stiffener; step S302, immersing the upper edge frame of the plate and the upper section of the stiffener in water and welding them into an integral component; step S303, smoothing the front and back surfaces of the integral component on a surface grinder, removing 0.5mm from each surface to obtain the upper component of the test plate.

[0010] Further, in one embodiment of the present invention, step S4 specifically includes: step S401, selecting 8 points, including the endpoints and midpoints of the 4 edges of the test base plate and the test plate, as fixing points; step S402, using F clamps to clamp the test base plate and the upper component of the test plate at 8 points, immersing the two in water for double-sided continuous spot welding to obtain the test plate.

[0011] Furthermore, in one embodiment of the present invention, in step S5, the test plate is smoothed on both sides on a surface grinder to grind the thickness of the test plate to the target size.

[0012] Furthermore, in one embodiment of the present invention, in step S7, ultrasonic thickness measurement and surface flatness scanning measurement are performed on the stiffened plate grid area. At the center of each grid area, 5 points are evenly selected along the stiffener direction, and the thickness error of each measurement point is <1%.

[0013] Furthermore, the surface flatness scan results showed that the maximum deflection deformation was <1%.

[0014] This invention proposes a method for suppressing deformation in the process of elastic thin-walled stiffened plates, comprising the following steps: Step S1, selecting a steel template with a thickness 8 times that of the target thickness; Step S2, fine processing of the stiffened plate base plate; Step S3, fine processing of the stiffened plate upper component; Step S4, welding the stiffened plate base plate and the stiffened plate upper component to form a test plate; Step S5, smoothing the front and back surfaces of the test plate; Step S6, milling the edge fixing area of ​​the stiffened plate; Step S7, performing ultrasonic thickness measurement and surface flatness scanning measurement on the stiffened plate grid area.

[0015] This method for suppressing deformation in elastic thin-walled stiffened plates is of great significance for studying the local hydroelasticity of ships, the evolution of surface load characteristics of locally elastic thin-walled stiffened plates, and the structural response characteristics of locally elastic thin-walled stiffened plates. This invention greatly improves the accuracy of local hydroelasticity tests on ships and meets the technical requirements of the tests. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0017] Figure 1 This is a flowchart of a method for suppressing deformation in an elastic thin-walled stiffened plate according to an embodiment of the present invention;

[0018] Figure 2 This is a carving diagram of the stiffened plate base and T-shaped rib base according to an embodiment of the present invention;

[0019] Figure 3 This is a diagram of the upper component of the stiffened plate according to an embodiment of the present invention;

[0020] Figure 4 This is an overall view of a stiffening plate according to an embodiment of the present invention;

[0021] Figure 5 This is a distribution diagram of the thickness measuring points within the stiffened plate grid according to an embodiment of the present invention;

[0022] Figure 6 This is an ultrasonic thickness measurement diagram of all thickness measuring points within the stiffened plate grid according to an embodiment of the present invention;

[0023] Figure 7 This is a diagram of a surface flatness scanning device for a stiffened plate according to an embodiment of the present invention;

[0024] Figure 8 This is a sensing aperture for measuring the surface flatness of the stiffened plate according to an embodiment of the present invention;

[0025] Figure 9 This is a scanned image of the surface flatness of a stiffened plate according to an embodiment of the present invention;

[0026] Figure 10This is an absolute error distribution diagram of three flatness scans of a test plate according to an embodiment of the present invention;

[0027] Figure 11 This refers to the thickness measurement data (mm) of 15 measurement points on the test plate according to an embodiment of the present invention, and the percentage of relative error. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0029] The following describes a method for suppressing deformation in an elastic thin-walled stiffened plate according to an embodiment of the present invention, with reference to the accompanying drawings. First, the method for suppressing deformation in an elastic thin-walled stiffened plate according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0030] Figure 1 This is a flowchart of a method for suppressing deformation in an elastic thin-walled stiffened plate according to an embodiment of the present invention.

[0031] like Figure 1 As shown, the deformation suppression method for the single-elastic thin-walled stiffened plate includes the following steps:

[0032] Step S1: Select a steel sheet with a thickness 8 times that of the target thickness;

[0033] Furthermore, step S2 specifically includes:

[0034] Step S201: On a milling machine, the steel jig is cut and milled to the length and width dimensions of the target test plate, while the plate thickness remains unchanged;

[0035] Step S202: The cut and milled plate is smoothed on both sides on a surface grinder, with 0.5mm removed from each side to ensure a smooth and flat surface.

[0036] Step S203: On a CNC machine tool, the plate is engraved with the grid and rib base to obtain the test plate base.

[0037] Furthermore, step S3 specifically includes:

[0038] Step S301: The upper edge of the plate frame and the upper section of the rib are individually processed to the target size, and the upper section of the rib has the same thickness as the rib base.

[0039] Step S302: Immerse the upper edge of the plate frame and the upper section of the rib in water and weld them into an integral component;

[0040] Step S303: The entire assembly is smoothed on both sides on a surface grinder, with 0.5mm removed from each side to obtain the upper assembly of the test board.

[0041] Furthermore, step S4 specifically includes:

[0042] Step S401: Select 8 points, including the endpoints and midpoints of the 4 edges of the test base plate and the test plate, as fixed points;

[0043] Step S402: Use F clamps to clamp the test base plate and the upper component of the test plate at 8 points, immerse the two in water and perform double-sided continuous spot welding to obtain the test plate;

[0044] Among them, F clip is a quick splicing clip.

[0045] Further, in step S5, the test plate is smoothed on both sides on a surface grinder to grind the thickness of the test plate to the target size;

[0046] Furthermore, in step S7, ultrasonic thickness measurement and surface flatness scanning are performed on the stiffened plate grid area. Five points are evenly selected along the stiffener direction at the center of each grid area, and the thickness error of each measurement point is <1%; the maximum deflection deformation of the surface flatness scanning result is <1%.

[0047] like Figure 2 As shown below, the deformation suppression method for the elastic thin-walled stiffened plate proposed in this invention will be further described in detail through a specific embodiment.

[0048] Taking a certain elastic thin-walled T-shaped stiffened plate as an example, the target dimensions of the plate are 400mm in length, 400mm in width, and 2.5mm in thickness.

[0049] In this embodiment, a steel jig with a thickness 8 times that of the target thickness is selected. In this embodiment, the target thickness is 2.5 mm, so the selected steel jig thickness is 20 mm.

[0050] On a milling machine, the steel jig is cut and milled to the desired length and width of the target test plate. The target dimensions are 400mm in length and 400mm in width, with the plate thickness remaining constant at 20mm.

[0051] After milling, the plate is smoothed on both sides on a surface grinder, removing 0.5mm from each side, at which point the plate thickness is 19mm. Holes are then positioned and drilled on the plate, with a diameter of 7mm.

[0052] On a CNC machine tool, the plate is engraved with a grid and a rib base to obtain the test plate base. The grid engraving size is 300mm, 98.5mm wide, and 16mm deep. The T-shaped rib base is 300mm long, 16mm high, and 3mm thick.

[0053] like Figure 3 As shown, the upper edge frame of the plate and the upper section of the T-shaped rib are individually machined to the target dimensions. The target dimensions of the upper edge frame of the plate are 320mm in length, 320mm in width, 21.5mm in height, and 10mm in thickness; the target dimensions of the T-shaped rib are 300mm in length, 10mm in width, 12mm in height, and 3mm in thickness. The upper section of the rib has the same thickness as the rib base. The upper edge frame of the plate and the upper section of the rib are immersed in water and welded into an integral component. The integral component is then ground smooth on both sides on a surface grinder, with 0.5mm removed from each side, to obtain the upper component of the test plate.

[0054] like Figure 4 As shown, eight points, including the endpoints and midpoints of the four edges of the test base plate and the test plate, are selected as fixing points. The test base plate and the upper component of the test plate are clamped at eight points using F-clamps. The two are then immersed in water for double-sided continuous spot welding to obtain the test plate. The test plate is then smoothed on both sides on a surface grinder, and the plate thickness is ground to the target size of 2.5 mm. The edge fixing area of ​​the stiffening plate is then milled.

[0055] like Figure 5-6 As shown, ultrasonic thickness measurement was performed on the stiffened slab grid area. Five points were evenly selected along the stiffener direction at the center of each grid area. The results of ultrasonic thickness measurement at all 15 points remained consistently around 2.57 mm (e.g., ...). Figure 11 As shown in the figure, the relative error is <1% (target value is 2.5mm), which meets the technical requirements.

[0056] like Figure 7-10 As shown, the flatness of the back surface of the stiffened plate was scanned. Forty-nine measuring points were set on the surface of the test plate, spaced 5cm x 5cm, and a white sensor aperture was arranged. The flatness of the test plate surface was measured three times. The scanning equipment was a GO! SCAN50 scanner with a scanning speed of 550,000 scans / s, a resolution of 0.5mm, and a scanning accuracy of 0.1mm. The results show that the maximum deflection percentage of the test plate in the three scans was 0.172%, 0.172%, and 0.171%, respectively, far less than the technical requirement of 1%. The deflection percentage was calculated based on the following formula:

[0057]

[0058] Among them, △Z i The distance from measuring point i to the defined plane is the deflection difference, in mm; L is the length of the test plate, 400 mm.

[0059] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0060] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0061] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more N executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of the invention pertain.

Claims

1. A method for suppressing deformation during the manufacturing process of an elastic thin-walled stiffened plate, characterized in that, Includes the following steps: Step S1: Select a steel sheet with a thickness 8 times that of the target thickness; Step S2: Refined processing of the stiffened bottom plate; Step S3: Refined processing of the upper components of the stiffened plate; Step S4: The stiffening plate bottom plate and the stiffening plate upper component are welded together to form a test plate; Step S5: Grind the front and back surfaces of the test plate until smooth. Step S6: Mill the edge fixing area of ​​the stiffening plate; Step S7: Perform ultrasonic thickness measurement and surface flatness scanning measurement on the stiffened plate grid area; The step S2, the fine processing of the stiffened plate bottom plate, specifically includes: Step S201: On a milling machine, the steel jig is cut and milled to the length and width dimensions of the target test plate, while the plate thickness remains unchanged; Step S202: The cut and milled plate is smoothed on both sides on a surface grinder, with 0.5mm removed from each side to ensure a smooth and flat surface. Step S203: On a CNC machine tool, the plate is engraved with the grid and rib base to obtain the test plate base plate; The fine processing of the upper component of the stiffened plate in step S3 specifically includes: Step S301: The upper edge of the plate frame and the upper section of the rib are individually processed to the target size, and the upper section of the rib has the same thickness as the rib base. Step S302: Immerse the upper edge of the plate frame and the upper section of the rib in water and weld them into an integral component; Step S303: The entire assembly is smoothed on both sides on a surface grinder, with 0.5mm removed from each side to obtain the upper assembly of the test board. Step S4, welding the stiffening plate bottom plate and the stiffening plate upper component to form a stiffening plate, specifically includes: Step S401: Select 8 points, including the endpoints and midpoints of the 4 edges of the test base plate and the test plate, as fixed points; Step S402: Use F clamps to clamp the test base plate and the upper component of the test plate at 8 points, immerse the two in water and perform double-sided continuous spot welding to obtain the test plate.

2. The method for suppressing deformation in the production of an elastic thin-walled stiffened plate according to claim 1, characterized in that, The test plate is smoothed on both sides on a surface grinder, and the thickness of the test plate is ground to the target size.

3. The method for suppressing deformation in the production of an elastic thin-walled stiffened plate according to claim 1, characterized in that, The ultrasonic thickness measurement and surface flatness scanning measurement of the stiffened plate grid area are performed. Five points are evenly selected along the stiffener direction at the center of each grid area, and the thickness error of each measurement point is <1%.

4. The method for suppressing deformation in the production of an elastic thin-walled stiffened plate according to claim 3, characterized in that, The surface flatness scan results show that the maximum deflection deformation is <1%.

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