Application of CATIA V5 in strength design of automobile parts 1

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Application of CATIA V5 in strength design of automobile parts 1 [Copy link]

CATIA is a CAD/CAM software developed by Dassault Aviation of France. It is sold in China by IBM. CATIA software enjoys a high reputation in the design fields of aircraft, automobiles, ships, etc. for its powerful functions. 100% of the world-renowned automobile companies have switched to CATIA design, and the domestic FAW Group has also invested nearly 100 million in CATIA, which shows that everyone recognizes CATIA software. Beiqi Foton Motor Company introduced CATIAV5 in 2003, and it showed obvious benefits in its Auman heavy trucks that year. CATIA software is being used more and more widely in automobile design. The following article takes the design improvement process of the power steering bracket as an example to briefly introduce the experience and experience of using CATIA software.
1. Fault presentation and analysis

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The steering booster bracket, as shown in (Figure 1-1), is a part used to fix the steering booster cylinder. Its strength and quality are directly related to the steering performance of the vehicle. Imagine that a heavy truck with a load of more than 20 tons running at high speed loses its directional control ability, and the consequences will be disastrous. When the prototype was produced, the debugging personnel found that the booster bracket twisted with the movement of the booster cylinder under no-load conditions, and there was a tendency to be torn if a load was added.
2. Traditional practices in the past
If the traditional design method is used, the problem parts will generally be strengthened, such as thickening the plate, increasing the weight, and improving the performance of the material. But where to add? How much? There is a great deal of blindness. If the analysis is performed by calculation method, the problem parts need to be subjected to force analysis, but for such parts with complex shapes, the traditional mechanical analysis method can only provide a roughly approximate result, not an accurate answer. And this kind of mechanical analysis requires designers to have a high foundation in theoretical mechanics and material mechanics, ample analysis time and rich design experience, and the latter is not available to most designers who have just started working. At present, only specialized research institutions in China can use calculation methods, and it is generally difficult for factories to carry out.
3. Introducing CATIA
Now by introducing CATIA for auxiliary design, we can simulate the ultimate stress state of the component during operation to find the stress concentration point and the maximum displacement point, so as to improve its stress condition.
The specific steps are shown in the following flow chart:

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As shown in Figure 1-2, the maximum stress point we obtained through analysis (point A) is consistent with the actual object, and the maximum displacement point is also consistent with our original expectations.

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Figure 2 Stress analysis diagram of the steering booster bracket under extreme stress

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Table 1 Stress gradient table

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Figure 3 Steering booster bracket limit stress deformation diagram

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Table 2 Deformation gradient table
As shown in Figure 1-2, the maximum stress point obtained by our analysis is consistent with the actual object (point A), and the maximum displacement point is consistent with our original expectations. The material is 235 MPa and the maximum stress concentration point reaches 559 MPa, with a difference of 324 MPa. For this reason, the wall thickness was first increased to 8 mm (Figure 4/B design). The maximum stress dropped from 559 MPa to 393 MPa, a decrease of 29%, and the weight increased by 5.6%. The stress reduction was not ideal; then an oblique rib was added at the maximum stress point (Figure 4/C design), and GPS analysis was performed again. The maximum stress and deformation decreased by 59%, but the deadweight increased by 44%. Then we tried to add reinforcing ribs in other places. After analysis, it was found that there was little effect. Finally, the entire component was filled, and it was found that the stress situation was even worse due to the increase in deadweight. It seems that it is difficult to solve the problem by simply strengthening the parts, and the structure of the parts needs to be adjusted. Finally, another structure (Figure 4/D design) was used for reference and adopted. This structure has better stress resistance. See (Figure 5 and Figure 6).

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