The Literary Life of a Science Leader

Chapter 93 NSR
What is Mechanical Part Failure?

Give a simple example.

Those who have engaged in engineering basically know a story about screwing.

Car models of the same brand can be divided into original imported vehicles and domestically assembled vehicles.

During the original assembly in Germany, the workers tightened the screws in strict accordance with the requirements of the work instructions, three turns forward and half a turn back; while in China assembly, the workers in the workshop thought it was taking off their pants and farting?Wouldn't it be enough to go straight into two and a half laps?

But with the passage of time, the impact of this half-circle came out. For the same car model, some parts of domestic cars have significantly higher failure and maintenance rates than imported cars.

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

After the screw is tightened, in order to prevent loosening, an additional pre-tightening force should be applied, so the pre-tightening force will be eliminated after loosening half a turn.The screw is in elastic deformation after tightening, especially under the condition of mild vibration load, such continuous pressure for a long time will produce creep, and after the screw becomes plastic deformation, its strength will be greatly reduced or even fail.

Backing off half a circle is to restore some elastic deformation and eliminate the pre-tightening stress at the same time. In the future, the deformation of the screw under continuous pressure is still in elastic deformation, and the probability of plastic strain and failure is greatly reduced, so that the screw can maintain continuous high-strength pressure.

But directly twisting two and a half turns will not achieve this effect.

As a result, there have been a lot of moral or Japanese blows. When you go online, you can basically see some German blows or daily blows, how about mechanical engineering, ingenuity, rigor and persistence, etc.

Also take the car engine level out for verification.

Mu Jingchi just laughed it off, not arguing.It is undeniable that there is a gap between China, Germany and RB, but Germany and RB are not as strong as imagined.

Even if it is that strong, there is no need to worry too much.

Who is the best country in the world to make cars now?

Germany, RB and Italy.

What do all three have in common?

They are all defeated countries!
Some other victorious countries, including the United States, are not as good as the three defeated countries in the automotive field.

Do you think this is a coincidence?
Germany, RB, and Italy are like the earth locked by sophons, and their technological upper limit is locked in the mechanical age.

Otherwise, how do you explain that Japan and Germany, which are so awesome in mechanical manufacturing, perform mediocre in aerospace, aviation, artificial intelligence, and computer chips.

On the contrary, France, which makes only average cars, has the world's second largest aircraft manufacturing capacity.

The angle is clearer, think from another angle.

If you are a top Huaxia S&T talent, regardless of immigration and income.

The careers you can engage in include: go to Chinese Academy of Sciences to study atomic bombs, go to North Industries to study missiles, go to space agency to study moon landing, go to State Grid to study ultra-high pressure, go to Dalian Shipyard to build aircraft carriers, go to COMAC to build large aircraft, go to Iron Boss Study high-speed rail, go to Huawei to study communications and Kirin, go to AT to study code writing, go to SAIC or Geely to study engines, etc.

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

To put it simply, are you willing to develop engines to increase the conversion efficiency of internal combustion engines by a few percent, or are you willing to research aerospace engines.

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

So, don't worry too much.

With the development of Huaxia's talents, more and more people will devote themselves to various scientific researches, and the gap between China and the world will become smaller and smaller.

Pulling away again, back to the topic.

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

Huaxia's development has always been limited by materials, including but not limited to material research and development, material applications, and material science theories.

However, many key technologies or theories are not open, nor will they form papers and put them in the database for people to learn.

For example, related cutting-edge technologies and material applications of aero-engines are simply not found.

Otherwise, Huaxia's aero engines would have zero foundation.

In order to break through aero engines, Huaxia is already acquiring shares in Ukrainian aero-engine giant Motor Sich. The chairman of the Ukrainian Defense Industry Group has confirmed the news.

However, the transaction is still under review by the Antitrust Commission.

It is conceivable that foreign countries have blocked China.

And once the acquisition is successful, Huaxia's aero-engine research and development will not be a zero foundation. Even if you can't buy those engineers, it is worthwhile just for the massive design drawings.

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

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

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

Moreover, the research results of many large foreign experimental institutions and multinational companies are not always released to the outside world. Many new material research results are transformed into finished materials and then sold out.

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

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

The material is limited, so what if there is even the best technology?
However, Zhang Chuyang and his team have further advanced the theoretical research on material fracture and damage, and have gone one step further in previous material research.

After understanding the fracture damage principle of materials and knowing more about the internal changes of materials, we can make targeted improvements in the use of materials.

This step also affects the material market involving [-] billion yuan, and it is also widely used in military industry.

So it means a lot.

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

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

"I don't have any great credit. It didn't work. I just got their credit." Zhang Chuyang was still a shy classmate, and he was a little embarrassed to be praised by Mu Jingchi like this.

"It's a pity that it's just failure due to fracture damage. There is still a big gap between us and foreign countries in the direction of failure of mechanical parts as a whole. Not to mention failure of mechanical parts under extreme conditions, which is a more complicated subject."

Although his face was flushed, Zhang Chuyang was not completely dazzled by the success of this scientific research.

This project was originally a project under the extreme conditions of Professor Yang's team, and he was just a small transparency among them. Although he was talented, his role in this project was not great.

"Don't worry, at least the sub-journal of SCI's top journal can be published."

Mu Jingchi comforted Zhang Chuyang, although the corresponding author certainly didn't need to think about it, but as far as the whole topic was concerned, they, the participants, were also able to publish papers.

Papers in the general direction are definitely useless, but the minutiae of the whole project can still be published by participants such as them. If they are lucky, they can be the first author.

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

Mu Jingchi gave a thumbs up, "Yes!"

(End of this chapter)