Supporting device design method

Abstract

The invention relates to a supporting device design method, and belongs to the field of device structure design. According to the method, firstly, the three-dimensional model of the supporting device is designed, then, the mid-plane features of the three-dimensional model are extracted, all solid structures in the three-dimensional model are converted into sheet structures with thickness parameters, the thickness parameters directly influence the design strength of the supporting device, and the thickness parameters are set to be parameterized sizes, so that the design strength of the supporting device is directly influenced by the thickness parameters. And if the sheet body structure under the current thickness parameter does not meet the design strength requirement based on finite element analysis, the corresponding thickness parameter can be directly modified until the three-dimensional model meets the corresponding design strength. Through the parameterization analysis method, the product design efficiency is improved, the traditional design period is shortened, and the overall efficiency of design production is improved.

Description

TECHNICAL FIELD

[0001] The application relates to a support device design method and belongs to the field of device structure design. BACKGROUND

[0002] A certain type of electrical equipment has a matching support device when in use. The design appearance, structure modeling and material selection should meet the static load strength requirement of bearing the self-weight of the electrical equipment, and also meet the requirements of simple use and convenient transfer. Based on the fact that the shape and structure of the electrical equipment are about 12666mm long, 1206mm in diameter and the overall mass is as high as 13.6 tons, the bearing capacity requirement of the matching support device is improved accordingly. Therefore, the designers design the support structure according to the experience design method, as shown in the prior art Nos. Figure 1 and Figure 2 The support device is mainly a steel frame structure formed by welding various machined plate parts, and the spatial structure is complex and the number of parts is as many as more than 20. The support device is 1800mm long, 560mm wide and 1170mm high, and the plate thickness is 20mm. The material is Q235, although the designers have adopted a certain hollow design, but the overall weight is still as high as 400kg, and the raw material cost is about 4500 yuan. The support device has large appearance size and high overall weight, which causes the problems of extremely inconvenient actual use, complicated transfer process, and difficult transportation.

[0003] The Chinese patent application publication No. CN115034008A discloses a vertical water turbine generator set main shaft support structure design method. The method performs finite element solving on the three-dimensional model of the support structure based on finite element analysis, and then iteratively optimizes the three-dimensional model of the support structure.

[0004] However, in the above scheme, if the finite element analysis result does not meet the requirement, the structure size of the related components of the support structure needs to be redesigned. Obviously, the design efficiency of the product is reduced. SUMMARY

[0005] The purpose of the application is to provide a support device design method to solve the problem of low design efficiency of the support device.

[0006] To achieve the above purpose, the scheme of the application includes: The method comprises the following steps: 1) designing a three-dimensional model of a support device for supporting electrical equipment; 2) extracting the middle surface features of the three-dimensional model, converting each entity structure in the three-dimensional model into a sheet structure with a corresponding thickness parameter, the thickness parameter being a size parameter that most affects the design strength of the support device, and setting the thickness parameter as a parameterized size; 3) performing finite element analysis on the sheet structure using finite element analysis software to determine whether the sheet structure under the corresponding thickness parameter meets the corresponding design strength requirements of the support device, and if not, modifying the thickness parameter until the sheet structure under the modified thickness parameter meets the corresponding design strength requirements of the support device.

[0007] Further, in step 3), the sheet structure is meshed based on shell elements using finite element analysis software, and after setting the corresponding boundary conditions for the meshed sheet structure, finite element analysis is performed to determine whether the sheet structure under the corresponding thickness parameter meets the corresponding design strength requirements of the support device.

[0008] Further, the mesh shape is a quadrilateral.

[0009] Further, the three-dimensional model is simplified before step 2) is performed.

[0010] Further, the entity structures in the three-dimensional model include an arc-shaped support plate for wrapping the electrical equipment, a grounding plate for grounding, and a plurality of connecting plates for connecting the arc-shaped support plate and the grounding plate.

[0011] Further, the material of the support device is aluminum alloy.

[0012] Further, the finite element analysis software is ansys.

[0013] The present application has the following advantages: the present application is an open-ended invention, which first designs a three-dimensional model of a support device, then extracts the middle surface features of the three-dimensional model, thereby converting each entity structure in the three-dimensional model into a sheet structure with a thickness parameter, and the thickness parameter directly affects the design strength of the support device, and the thickness parameter is set as a parameterized size, so if the sheet structure under the current thickness parameter does not meet the design strength requirements based on finite element analysis, the corresponding thickness parameter can be directly modified until the three-dimensional model meets the corresponding design strength. The present application improves product design efficiency, shortens the traditional design cycle, improves the traditional design method, reduces production material costs by at least 87.5%, and significantly reduces production and processing costs after simplifying the structure, while improving overall design and production efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1is a three-dimensional perspective view of a support device in the prior art; Figure 2 is a front view of a support device in the prior art; Figure 3 is a design flow diagram of the present application; Figure 4 is a three-dimensional perspective view of a support device of the present application; Figure 5 is a top view of a support device of the present application with size identification; Figure 6 is a front view of a support device of the present application; Figure 7 is a sheet structure diagram of a support device of the present application; Figure 8 is a property diagram of a connecting plate in a sheet structure of a support device of the present application; Figure 9 is a grid unit diagram of the present application; Figure 10 is a support device diagram after grid division of the present application; Figure 11 is a boundary condition application diagram during finite element analysis of the present application; Figure 12 is an equivalent stress diagram during finite element analysis of the present application; Figure 13 is a maximum shear stress diagram during finite element analysis of the present application; Figure 14 is a practical product diagram of the present application. DETAILED DESCRIPTION

[0015] To make the purpose, technical scheme and advantages of the present application more clear and explicit, the present application will be further described in detail below with reference to the drawings and embodiments.

[0016] The idea of the present application is to extract mid-surface features from a designed three-dimensional model, thereby converting each entity structure in the three-dimensional model into a sheet structure with a thickness parameter that most affects the design strength, and setting the corresponding thickness parameter as a parameterized size. At this time, even if the corresponding thickness parameter does not meet the design strength requirement, the designed model can be modified to meet the corresponding requirement by modifying the corresponding thickness parameter, thereby avoiding repeated design of the three-dimensional model.

[0017] Method embodiment: The present embodiment provides a support device design method, as shown in Figure 3 , including the following steps: S1, design a three-dimensional model of the support device. Further, simplify the corresponding entity structure in the designed three-dimensional model, that is, replace the non-key features such as chamfer, round, blunt edge, hole, and groove with small size around the three-dimensional model with plane and straight edge, so as to reduce the total size of the feature of the three-dimensional model structure and improve the parameterizability of the design.

[0018] S2, extract the middle surface feature of the simplified three-dimensional model, convert each entity structure in the three-dimensional model into a sheet structure with a thickness parameter, and set the corresponding thickness parameter as a parameterized size. The thickness parameter is the size parameter that most affects the design strength of the corresponding entity structure. By simplifying the three-dimensional model into a sheet structure, the problems of complex entity structure features, parameterized design and optimization difficulties, and the like are solved, and the design efficiency and repeatability are significantly improved.

[0019] S3, use the corresponding finite element analysis software to perform finite element analysis on the obtained sheet structure, determine whether the sheet structure under the corresponding thickness parameter meets the design strength requirements of the device, and if not, modify the thickness parameter and then continue the finite element analysis until the sheet structure under the modified thickness parameter meets the design strength requirements of the device.

[0020] Specifically, the finite element analysis process includes: first, using the finite element analysis software to perform mesh division based on shell elements on the sheet structure, then setting the corresponding boundary conditions for the mesh-divided sheet structure, and performing finite element analysis. The mesh elements divided are quadrilateral mesh elements, which effectively reduces the number of mesh element divisions and the number of nodes, improves the convergence of the solution in the analysis process, reduces the calculation time, and improves the result accuracy.

[0021] The above process is described below with a specific example: The designed three-dimensional model of the device is shown in Figure 4 , Figure 5 and Figure 6 The device is used to support an electrical equipment and is mainly composed of an aluminum plate structure, which is divided into three layers, the upper layer is an arc support plate for wrapping the electrical equipment, the lower layer is a grounding plate for contacting the ground, and the middle layer is a plurality of connecting plates for connecting the arc support plate and the grounding plate. The connecting plate is composed of seven support plates and two side plates, and the initial value of the thickness of all plates is 5mm. The material is uniformly aluminum alloy in 5083, H112 state, or other materials with similar strength performance. Then the three-dimensional model is simplified.

[0022] The simplified three-dimensional model is subjected to middle surface feature extraction, and each entity structure in the simplified three-dimensional model is converted into a sheet structure with a thickness parameter, as shown in Figure 7and the thickness parameter is set as the parameterized size. Among them, for the three-dimensional model, the size parameter that most affects the design strength of the device is different for each entity structure, for example, for the arc support plate, the size parameter that most affects the design strength of the device is the distance between the outer arc surface and the inner arc surface, so the distance parameter is the thickness parameter of the arc support plate, and the distance is set as the parameterized size; and for the grounding plate, as shown in Figure 8 , the size parameter that most affects the design strength of the device is the height of the grounding plate, so the height of the grounding plate is the thickness parameter of the grounding plate, and is set as the parameterized size.

[0023] After the three-dimensional model is extracted as a sheet structure feature, ANSYS is used for meshing in the shell element, and the corresponding mesh elements are quadrilateral mesh elements, as shown in Figure 9 and Figure 10 Compared with the entity hexahedral element, the number of nodes is reduced by two-thirds, and the number of elements and nodes is greatly reduced (only 248,130 mesh elements and 215,687 nodes are generated). The mesh shape is uniform, regular, correct and high quality, solving the problems of poor design repeatability and low design efficiency caused by the reasons of complex device entity structure model, complex structure feature, parameterized design difficulty, and high dependence on computer performance.

[0024] Then the sheet structure meshed by ANSYS is used for finite element analysis, and the corresponding boundary conditions are set, as shown in Figure 11 , constraints are applied (for example, displacement is not allowed) and corresponding loads are applied. Since 13.6 tons in a certain electrical equipment, the support device is used in pairs, therefore, one support device bears about 6.8 tons. Considering the safety of actual use, a safety factor load of about 1.5 times is applied to the arc support surface of the arc support plate of the support device, that is, a load of 10 tons. The 10-ton bearing capacity of the support device, the parameterized analysis result is as shown in Figure 12 and Figure 13 According to the analysis results of Figure 12 and Figure 13 , the local maximum stress of the support device is 124 MPa, and the stress at the arc support surface is about 50 MPa, and the stress of the remaining support plate and grounding plate is below 20 MPa. Among them, the most dangerous area in the structure is the local area of the arc support surface, and the maximum stress is 124 MPa. According to the standard, the yield stress of aluminum alloy 5083, H112 state is 275 MPa, at this time, the safety factor of the most dangerous area in the design structure is 2.22, which meets the bearing strength requirement (if not, modify the corresponding thickness parameter, for example, increase the thickness parameter of the arc support plate), since the load is applied with a safety factor of 1.5 times, so the overall safety factor is 3.32 by multiplying the above two.

[0025] At this time, the actual product manufactured by the three-dimensional model satisfying the design strength as shown in FIG. 1 is as shown in FIG. 2. Figure 14

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit it. Although the present application has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application. Any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered within the protection scope of the claims of the present application.​

Claims

1. A support device design method characterized by comprising: The method comprises the following steps: 1) designing a three-dimensional model of a support device for supporting an electrical device; 2) extracting a median surface feature of the three-dimensional model, converting each solid structure in the three-dimensional model into a sheet structure with a corresponding thickness parameter, the thickness parameter being a size parameter that most affects the design strength of the support device, and setting the thickness parameter as a parameterized size; 3) performing finite element analysis on the sheet structure by using finite element analysis software, determining whether the sheet structure under the corresponding thickness parameter meets the requirement of the corresponding design strength of the support device, and if not, modifying the thickness parameter until the sheet structure under the modified thickness parameter meets the requirement of the corresponding design strength of the support device.

2. The support arrangement design method according to claim 1, characterized by In the step 3), the sheet structure is meshed based on shell elements by using the finite element analysis software, and the meshed sheet structure is set with corresponding boundary conditions and then subjected to finite element analysis to determine whether the sheet structure under the corresponding thickness parameter meets the requirement of the corresponding design strength of the support device.

3. The support arrangement design method according to claim 2, characterized by The mesh shape is quadrilateral.

4. The support arrangement design method according to claim 1, characterized by The three-dimensional model is also simplified before the step 2) is performed.

5. The support arrangement design method according to claim 1, characterized by The solid structure in the three-dimensional model comprises an arc supporting plate with a set arc for wrapping the electrical device, a grounding plate for grounding, and a plurality of connecting plates for connecting the arc supporting plate and the grounding plate.

6. The support arrangement design method according to claim 5, characterized by The material of the support device is aluminum alloy.

7. The support arrangement design method according to claim 1, characterized by The finite element analysis software is ANSYS.

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