What is Mechanical Part Failure?

Let's take a simple example.

Anyone who has worked in engineering basically knows a story of screwing.

The car models of the same brand are divided into original imported and domestic assembly.

When it was originally installed in Germany, the workers screwed in strict accordance with the requirements of the work instructions to enter three circles and then retreat half a circle; while during the assembly in Huaxia, the workers in the workshop felt that this was not taking off their pants and farting? Wouldn't it be enough to go directly into two and a half circles?

But as time passed, the impact of this half-circle came out, and for the same car model, some parts of domestic cars had significantly higher breakdowns and repair rates than imported cars.

In fact, it is a problem of failure of mechanical parts.

After the screw is tightened, an additional preload should be applied to prevent loosening, so that the preload will be eliminated after half a turn. The screw is in elastic deformation after tightening, especially in the case of mild vibration load, long-term continuous pressure will produce creep, and after the screw becomes plastic deformation, its strength will drop greatly or even fail.

Returning half a turn is to restore the elastic deformation somewhat, and at the same time eliminate the preload stress, and then the screw is deformed under continuous pressure or in the elastic deformation, and the probability of plastic strain and failure is greatly reduced, so that the screw can maintain continuous high pressure pressure.

And directly twisting two and a half turns will not achieve such an effect.

As a result, it has also caused a lot of German blowing or Japanese blowing, and when you go online, you can basically see some German blowing or Japanese blowing, how about mechanical engineering, ingenuity, rigorous perseverance, and so on.

The level of the car engine is also taken out for verification.

Mu Jingchi smiled at this and did not argue. It is undeniable that there is a gap between China and Germany and RB, but Germany and RB are not as strong as imagined.

Even if it's that strong, you don't have to worry too much.

Who is the best country in the world to build cars right now?

Germany, RB and Italy.

What do the three have in common?

It's all a defeated country!

Some of the other victorious powers, including the United States, were inferior to the three defeated countries in the field of automobiles.

Do you think it's a coincidence?

Germany, RB, and Italy are like the Earth locked by Chiko, and their technological ceilings are locked in the mechanical age.

Otherwise, how do you explain that Japan and Germany, which have such a good mechanical manufacturing, have average performance in aerospace, aviation, artificial intelligence, and computer chips.

On the contrary, France, which is generally made of automobiles, has the world's second largest aircraft manufacturing capacity.

The angle is clearer, think about it from a different angle.

If you are a top talent of Huaxia Institute of Technology, regardless of immigration and income.

The occupations you can engage in include: going to the Chinese Academy of Sciences to study the atomic bomb, going to NORINCO to study missiles, going to the space agency to study the moon landing, going to the State Grid to study ultra-high voltage, going to Dalian Shipyard to build aircraft carriers, going to Commercial Aviation to build large aircraft, going to Iron Boss to study high-speed rail, going to Huawei to study communications and Kirin, going to AT to study and writing code, going to SAIC or Geely to study engines, and so on.

But if you were born in Germany, then your best bet is to go to Volkswagen to study engines.

To put it more simply, would you rather develop an engine that would increase the conversion efficiency of the internal combustion engine by a few percent, or would you rather study a space engine?

Send your wisdom and talent, human courage and perseverance to the infinite universe, and engrave your name on the starry sky?

So, don't worry too much.

With the development of talents in China, more and more people will devote themselves to various scientific and engineering research, and the gap between China and the world will become smaller and smaller.

It's back to the point.

Failure analysis of mechanical parts is a major topic, which generally includes excessive deformation, fracture, fatigue fracture, wear failure, corrosion failure, creep deformation and fracture failure.

The development of Huaxia has always been limited by materials, including but not limited to material research and development, material application, and material science theory.

Many key technologies or theories are not open, and they will not be put into a database for people to learn.

For example, the relevant cutting-edge technology and material applications of aero engines cannot be found at all.

Otherwise, Huaxia's aero engine will be said to be zero-based.

In order to break through the aero engine, Huaxia is already acquiring the shares of the Ukrainian aero-engine giant Madasich, and the chairman of the Ukrainian Defense Industry Group has confirmed this news.

However, the deal is still under review by the Anti-Monopoly Committee.

It is conceivable that foreign countries have imposed a blockade on China.

Once the acquisition is successful, Huaxia's aero-engine research and development will not be considered zero-based, even if you can't buy those engineers, just the massive design drawings are worth it.

The reason why Mu Jingchi said that Zhang Chuyang and his team are a great credit is because their material fracture and damage topic has a significant role in promoting material application and material theory.

The research of fracture mechanics and damage mechanics in materials has always been lower than that of foreign countries, and Huaxia is still lagging behind in the theoretical and experimental research of materials.

Although there are indeed achievements in breaking the foreign blockade in some aspects, in terms of comprehensive material strength, Huaxia is not as good as Europe and the United States.

Moreover, the research results of many large foreign experimental institutions and multinational enterprises are not published to the outside world, and many new material scientific research achievements are transformed into finished materials and then sold out.

Materials are the foundation of all industries, and without materials with good performance, everything is empty talk.

Compared with other aspects of equipment or patented technology restrictions, foreign restrictions on materials appear more thorough and hidden.

Limiting the materials, what if there is the best technology?

However, Zhang Chuyang and his team have further advanced the theoretical research on material fracture and damage, and have taken a step forward in the previous material research.

If we understand the principle of fracture damage of materials and know more changes within the materials, we can make corresponding improvements when the materials are used.

This step also affects the material market involving 100 billion yuan, and it also has a great application in the military industry.

So it means a lot.

It's just that it's hard for ordinary people to see.

As a member of the project team, Zhang Chuyang is also honored.

"I don't have any great credit, it doesn't work, it's just their light. Zhang Chuyang is still a shy classmate, and he is still a little embarrassed to be praised by Mu Jingchi like this.

"It's a pity that it's just the fracture damage failure, and there is still a big gap between us and foreign countries in the direction of the overall mechanical parts failure. Not to mention the failure of mechanical parts under extreme conditions, which is an even more complex subject. ”

Despite the flushing of his face, Zhang Chuyang was still not completely carried away by the success of this scientific research.

This project is a project under Professor Yang's extreme conditions team, and he is only a small transparent one, although he has talent, but his role in this project is not great.

"Don't worry, at least you can publish the sub-journal of SCI's top magazine. ”

Mu Jingchi comforted Zhang Chuyang, although the corresponding author definitely doesn't need to think about it, but for this whole topic, they, the participants, are also able to publish papers.

The paper in the general direction is definitely not fun, but the details of the whole project can still be sent by them, the participants, and if they are lucky, they can be mixed with the first author.

Zhang Chuyang scratched his head and smiled, "I think I can vote for NSR." ”

Mu Jingchi gave a thumbs up, "Yes!"