Chapter 828 It’s Just Equipment, Buy It!

Geological exploration is not an easy and pleasant task even if the precise coordinates have been obtained.

Fortunately, today's technical equipment, especially vehicles and helicopters, are relatively complete, and safety is relatively guaranteed.

But if a point is to be dug deep, it is still normal to take a few months at the shortest and a few years at the longest.

Therefore, after deploying some key points of the exploration work, Chang Haonan and Meng Zhenyuan returned to Beijing University of Aeronautics and Astronautics.

For them, all they can do now is wait.

Fortunately, Chang Haonan has no shortage of projects.

In the next half month, in addition to routinely paying attention to the progress of the Richey flow surgical method every day, he guided Li Yabo to carry out his graduation project.

In fact, it was not until the graduation project before the Spring Festival that Chang Haonan knew what the so-called "1-meter-class all-composite shell" specifically meant -

Gaofei wanted to develop a brand-new engine nacelle for the C808 passenger aircraft that was about to be put into mass production.

It is the thing that fixes the engine to the fuselage.

The diameter is about 1.3 meters.

If successful, the weight of the aircraft can be reduced by about 300kg.

I can only say that the technology is promising in the future.

But it is not feasible for the time being.

At present, almost all high-grade composite materials used in China rely on imports, and the cost is very high.

The weight saved by replacing titanium aluminum alloy with carbon fiber, even if it is extended to the entire life cycle, is not as much as the extra cost spent in the manufacturing process.

Of course, there is nothing wrong with doing some research in advance.

After all, there will be many places where similar designs will be needed in the future.

In the long run, it is a general trend to replace traditional alloys with carbon-based composite materials in the outer shells of launch vehicles and ballistic missiles, the fuselages of large aircraft, and even the fan blades and casings of turbofan engines, where the working environment is not particularly harsh and the probability of damage is relatively low.

Just treat it as a technical reserve.

Of course, for an undergraduate student doing a graduation project, these are still relatively far away.

So Chang Haonan's requirement for Li Yabo is to design a theoretically feasible overall plan.

The main purpose is to train the latter's ability to solve problems using existing tools.

Otherwise, if the students of the creator of TORCH Multiphysics can't play the software developed by their own teacher, it would be too embarrassing to say it out.

However, life is like this sometimes.

When you don't have expectations for something, it often gives an unexpected result.

...

One day in late March, when Chang Haonan was replying to Professor Perelman's email asking about the progress, Li Yabo suddenly poked his head in from the office:

"Teacher, please take a look, the simulation results here seem a bit strange..."

These days, students with laptops are naturally rare, so Chang Haonan could only follow Li Yabo to the student office to check the situation.

It's called a student office, but there are fewer students than teachers in the Torch Laboratory now, so it's actually equivalent to Li Yabo alone.

So the young man simply moved his luggage from the dormitory and started his life as a 007 liver emperor.

After entering the door, Chang Haonan carefully bypassed a folding bed and came to Li Yabo's workstation.

On the computer screen, a finite element model with a thick middle and thin ends, slightly cigar-shaped, was displayed.

It was the overall plan of the engine nacelle he designed.

Chang Haonan came close to the screen and quickly read the results of the finite element calculation-

In 1999, that is, last year, a hardware engineer named Huang Renxun officially coined the term "GPU".

In fact, the processor that assists the CPU in graphics processing had its prototype as early as the 1980s.

But the GeForce256 launched by NVIDIA brought an epoch-making function.

Real-time programmable shading technology.

TORCH Multiphysics soon launched a free (but not free shipping and storage carrier material costs) and optional function update.

When the user's computer is equipped with an independent GPU, the results of the finite element calculation can be directly superimposed on the surface of the 3D model in the form of graphic rendering.

Instead of only being able to output a dry table as in the past.

Although there is no difference between the two in terms of results.

But for the human eye, the former method is obviously much more intuitive.

Therefore, Chang Haonan can now almost see at a glance that the design on Li Yabo's computer has basically met the project requirements proposed by Gao Fei.

"This result seems to be okay..."

He stood up again:

"Do you think there is something strange?"

At this time, Chang Haonan glanced at the annotation in the lower right corner of the screen.

It was written there the properties of the material he chose.

Young's modulus 700Gpa...

The corners of his mouth twitched fiercely.

There is no need to look at other parameters.

It is definitely T700 carbon fiber.

It can only be said that you don't know how expensive firewood and rice are until you manage the household.

T700 has only been put into commercial use in the past two years, and because the production capacity cannot be increased, the unit price is quite high.

If this kind of thing is used in large quantities on a 50-ton regional aircraft, I'm afraid it will be beaten to death by users...

Fortunately, it is still in the design stage. Anyway, judging from the standards of hand training, the problem is not big.

"This is it."

Li Yabo continued to enlarge the 3D model as he spoke.

Finally, Chang Haonan discovered that the carbon fiber structure on the screen was not just a shell modeled.

Rather, it is composed of many thin layers.

"Have you already studied the impact of composite laminate structures on performance?"

Chang Haonan was a little surprised.

"Yes, I think if we just provide an overall design plan, then Party A should be able to do it on its own, and it doesn't fully reflect the need to find our research team to solve the problem."

Li Yabo's first words made Chang Haonan very satisfied.

Although I kind of dislike the Haofei Group.

"After I tried several different layup plans, I found that the orthogonal lamination was significantly better in terms of ability to withstand shear loads and lateral loads, but this result was different from what I saw when I was on a business trip to Haofei Group. It’s not the same…”

"Also, even if the layers are orthogonal, the results of my two calculations will be different..."

"..."

In a daze, Chang Haonan seemed to see himself in the other person a few years ago.

Full of subjective initiative.

Of course, after all, he is a true undergraduate, so there is definitely still a huge gap between his ability and his own back then.

However, this is not the most important thing.

"That's not surprising."

He listened quietly to what the other party said, and then replied:

"The anisotropy of this type of carbon fiber-reinforced composite material is very complex, the interlayer strength is unstable, and the thermodynamic and mechanical properties of the fiber and matrix are very different. We, or not only us, all over the world are very concerned about this material. The nature of it is still not fully understood.”

"So, although the current TORCH Multiphysics can use your method to model the structure of multi-layer composite materials, it is unable to perform accurate numerical simulations in this case."

"This is why I told you before, as long as we can design a theoretically feasible overall plan."

After hearing Chang Haonan's explanation, Li Yabo showed a slightly embarrassed look on his face:

"This...it turns out to be like this..."

He scratched his head as he said:

"Then aren't these all useless efforts..."

Originally, Li Yabo wanted to secretly do the whole job and shock the teacher for a whole year.

As a result, I didn't finish my job in the end, and I had to go to the teacher to help find the reason.

"That can't be said."

Chang Haonan could also roughly guess what the other party was thinking, and shook his head with a smile:

"After all, you have done the entire modeling and calculation process yourself. It will be a rare experience for your future research work."

"Some experiences can only be learned through failure."

Li Yabo nodded somewhat disappointedly.

But Chang Haonan's next words made his eyes light up:

"However, if you are really interested in the microstructure of composite materials, then I can directly purchase a batch of related equipment and materials for you and study it experimentally."

"Really...really?"

Li Yabo could hardly believe his ears:

"I asked before when I went to Haojing on a business trip. The equipment and materials are very expensive..."

Obviously, he had already secretly understood the situation.

Before Li Yabo finished speaking, Chang Haonan waved his hand:

"The equipment used for laboratory-level research is different from their industrial production. The cost is not that exaggerated. You, teacher, and I can still afford it."

"It's just that you have to think clearly. Strictly speaking, this is materials science, not the field of structural mechanics. Experimental research is far more difficult and troublesome than numerical calculations..."

"I've thought it through."

Li Yabo replied firmly.

"Well."

Seeing that his student was so persistent, Chang Haonan could no longer discourage him:

"With your current design, it's no problem to take it to graduate school."

He said and pointed to the model on the computer screen:

"So, from now on, I will officially treat you as a graduate student."

Hearing this, Li Yabo couldn't help but sit up straight.

Although he didn't express his position, this action said everything.

Chang Haonan nodded slightly when he saw this, and then said in a solemn tone:

"I will give you a month to write a proposal report on the research on the microstructure of composite materials and attach the experimental equipment and materials you need."

"If there is nothing wrong with the report, I will prepare it for you as soon as possible. Do you understand?"