Advanced Sheet Metal Design Using NX Cad Challenge_7_ Metal bracket-II

Designing a Complex Bracket Using Siemens Nx

Objective

To design a complex bracket using the sheet metal application in Siemens NX. And to use a STEP file and use it to work with flattening and forming commands in modelling application of Siemens NX.

Introduction

Sheet metal design is a vast domain in the design industry. It is used in many sectors inlcuding the automotive sector. In this sheet metal complex bracket design we will look at the design approach using the Siemens NX (CAD) software through various diagrams, explanations and images. We will also see what is a neutral data file and where it is used, we will also work on a neutral data file in Siemens NX to perform flattening and forming operations. 

Design Approach

Figure 1 above shows the flow chart of the methods used to acheive the final design of the complex bracket.

Description

Initially, required sketch was drawn, to which a contour flange was created using the contour flange command in the sheet metal application of the software. Another sketch was created to remove an unwanted section from the bracket already created using normal cutout option. Break corner command was then used to change the appreance of certain corners with different radius. The model was unbended and the various holes and cutouts were created using holes and normal cutout options creating sketches as required. The model was rebended using the rebend command. Advanced flanges were added at required spots. Normal cutouts were repeated using previously created sketch to ensure the correct shape was maintained which was hampered while creating advanced flange on the top section of the model. Planes were chosen and four gusstes were created using the gussets option. 

Screen Shots

Figure 2 shows the isometric view of the designed complex bracket.

Figure 3 shows the front view of the complex bracket.

Figure 4 shows the side view of the complex bracket.

Figure 5 shows the back view of the complex bracket.

Figure 6 above shows the flat solid view of the complex bracket.

Drawings

Figure 7 above shows the 2D drawing of the complex bracket.

Figure 8 above shows the flat pattern for the complex bracket designed using NX.

What is neutral data files and what it means?

Neutral Data Files are files that are formatted text files which contains information about parts and assemblies created in any CAD software. The neutral data files are created by any CAD software which makes it easy to be used elsewhere in wide variety of fields and its range of software. A neutral data file can be created out of any part or an assembly created using a CAD software. Neutral data files of parts contain information about its geometry and features, whereas neutral data files of assembly contains information about how parts subassemblies are assembled in the assembly and also other general information about the parts. Neutral data file for an assembly will have neutral data files for each component along with individual part file names.

There are various neutral file formats available within highly regarded CAD software, most commonly used are IGES or STEP. Other formats include VDA-FS, PDES, Parasolid and DXF, DXF specifically being for interchange of designs. There are various other third party translators available as well. STEP is the most preferred format due to various reasons, one being availability of data related to attributes. STEP is also the best solution to solve the extrinsic problems, extending its current capabilities to support 2-D parametric sections, 3-D parametric assemblies, and history-based modeling. STEP also allows for minimal data exchange problems. Some examples of data exchange problems include loss of the architectural structure, change in the names of parts with numbers or names assigned to the directories where they are stored, loss of bodies from the assemblies, displaced details of their correct position relative to the original model, loss of the original color of the parts, displaying the construction lines that are hidden in the original product, etc.

Where are neutral data files used?

A neutral data file can help derive information which can be further utilized to create interfaces with other programs. It is also possible to open files of older version other CAD software using neutral data files.

Neutral data files have evolved to be a savior, saving companies and industries hundreds of dollars. Sharing CAD files with different toolsets have been a well-known and a costly industrial problem. Neutral data files are used in many segments of engineering industries and can be used in any software in the domains of CFD, FEA, or even in the design segment where companies usually prefer using different make of a CAD software. Neutral data files provide easy and faster access to files without having to buy or learn all software available in the market only to be able to access a specific file. Without neutral data files, accessing files would have been a very inefficient, challenging and cost incurring step for industries and customers.

The neutral data files have been very beneficial and have led industries to achieve productive co-simulation. By coupling design with different engineering disciplines, this format has also encouraged collaboration across engineering teams and synthesized the design process.

Flattening and forming

Case 1

We use the neutral data of .stp formal file and convert it into .prt fromat. We now apply flattening and forming application in the modeeling application instead of sheet metal design apllication to acheive a flat solid of the file. The Orginal body of the model is shown in figure 9 below. Figure 10 and 11 shows the solid body acheived using the flattening and forming command.

Figure 9 shows the original body of the part file extracted from the STEP format using Siemens NX.

Figure 10 shows the isometric view of the final flattened (like flat body in sheet metal application) and thickened body.

Figure 11 shows the front view of the final flattened and thickened body.

Case 2

In the second case, the converted neutral data file is used to extract a thin surface freom the original body seen in figure 9 above and figure 12 below shows the extracted geomtery. The extracted geomtery is then flattened using flattening command within flattening and forming option. A new sketch is then created on flattened solid. The newly created sketch is then transferred on the originally extracted surface using the flattening and reuse command within the flattening and forming option. The newly transferred sketch is then cut using trim sheet option. The altered sheet is now thickened and final result acheived can be seen in figure 13 below. 

Figure 12 shows the surface body extracted using the extract geometry command, ready to be processed further. 

Figure 13 shows the final processed body, the blue sketches are the newly formed trims using various techniques dicussed above. 

Conclusion

The complex bracket was designed and the drawings were successfully displayed in this project report. The model was designed and the drawings and flat pattern drawings were created using Siemens NX. We have also seen and discussed what is a neutral data file and where it is used, we have also worked on a neutral data file in Siemens NX to perform flattening and forming operations.