Chapter 543 There Are Four Solutions to This Problem (4K Large Chapter)

Shocked, Chang Haonan quickly realized that being able to ask for his opinion on such an important personnel appointment was definitely a high degree of trust in him by the organization.

Although Ding Gaoheng said that he planned to let Lan Xinzhi take charge of the Equipment Industry Department, the leaders of the second-level bureaus of ministries and commissions generally do not belong to the central management sequence.

But this is not an ordinary job transfer after all, but a candidate for a new department leadership position spawned in a round of large-scale organizational adjustments.

Moreover, this new department is also the focus of many confrontations.

It is definitely not something that the director of the Science and Technology Commission can make casually.

Including coming to Zhiqiu to ask his views on the candidates is probably not the case, or at least it is not just what Ding Gaoheng meant.

"Okay, I will come up with the results before the conference."

Chang Haonan replied seriously.

After finalizing the matter involving organizational appointment, Ding Gaoheng's expression relaxed a lot.

In fact, it was not entirely his intention to seek advice from Chang Haonan on the selection of leaders of the Equipment Industry Department.

However, the superiors' instructions on this were relatively vague, and they only mentioned that "pay attention to soliciting the opinions of some core technical personnel when appointing key positions."

Chang Haonan's name did not appear directly.

That's why Ding Gaoheng was a little confused before he spoke.

After all, the matter of organizational adjustment and reform does mean walking on thin ice.

Now that I have said it, I don’t have so many worries anymore.

Of course, on the other hand, Chang Haonan's multi-faceted reliability and age-beyond maturity have been proven many times by himself in the past two years.

Especially through the Boeing-McDonnell Douglas merger, almost the entire civil aviation industry in China has been revitalized.

To put it bluntly, his promotion of the aviation industry in the past two years has exceeded that of the previous two decades.

It can be called far-sighted.

Then, it is reasonable to believe that even if the same person cannot create the same miracle in the field of mechanical industry, at least it will not be too bad.

This was also an important reason why Ding Gaoheng finally made up his mind to speak.

Of course, those forces that want to hinder China's industrial development cannot just give up.

Aviation and machinery manufacturing are, after all, two related but parallel industries.

It seems a bit unconvincing to always use past achievements as bargaining chips.

It would be best to create something new.

"Xiao Chang, please explain to me."

Ding Gaoheng resumed his relaxed sitting posture, but did not move to other topics:

"When do you plan to complete this die forging press and put it into production?"

"I need to determine how many resources to allocate to the Equipment Industry Department in the past two years based on your timetable."

Although the Committee of Science, Technology and Industry has much more authority than before, the unified authority and responsibilities also mean that there are many more places to spend money, even a lot of money.

For example, the aviation industrial park that has been confirmed to be located in Luzhou has taken up a lot of this year's funding.

The manufacturing industry is a typical high-investment, long-cycle industry, and it is impossible to see money back within one or two years.

Therefore, in terms of funds, not to mention tightness, at least not to the level of deep pockets.

After talking about it for this reason, Chang Haonan thought about it for a while and decided to tell the truth.

After all, this also affects the number of resources that the die forging press can obtain after entering the production process.

"If resources are sufficient, our first priority plan is to strive to put the equipment into production before October 1999, which can also be regarded as a gift to the 50th anniversary of the National Day."

To be honest, National Day gifts are both formalistic and morale-boosting.

However, in the dark stage before dawn in 1999, it is obviously more inclined to the latter.

China in this era really needs confidence.

In the last life, during the National Day military parade in 1999, not only did the missiles that had just been tested and not yet finalized be brought out to support the scene, but the imported S300 anti-aircraft missiles were even given the name of Hongqi 15, pretending to look like No. 11 Engineering got the production line that way.

For a time, it really had the effect of confusing the fake with the real thing.

So much so that relevant urban legends are still circulating more than 20 years later.

Under this background, if a heavy-duty die forging press, a powerful and important instrument with few units in the world, can really be put into production, it will definitely be regarded as a first-class model effect.

Not to mention the economic benefits brought by the way.

Ding Gaoheng's hand shook as he just picked up the thermos cup.

Even though he had been mentally prepared before, he never expected that the time node set by Chang Haonan would be before the new century.

Ding Gaoheng, who barely suppressed the shock in his heart and remained calm on the surface, gave up drinking water, put the cup back on the table, and calmly wiped the water stains that had just spilled on his shirt:

"The 50th anniversary gift... is a good title. If it can be done, it will definitely be great news for us, especially the Equipment Industry Department, and it can also stop many people's mouths."

At this point, perhaps because he was worried about putting too much pressure on Chang Haonan, he changed the topic again:

"However, this time point is a bit exaggerated, and I won't talk about it for the time being, so don't put too much pressure on your side. Ensuring the smoothness of the project and the reliability of the equipment are the top priority."

"Then...the resources of the Equipment Industry Department..."

Chang Haonan asked tentatively.

"Configure it according to the time node you mentioned. Under the premise of ensuring that the basic business of other departments is not affected, as long as our Science and Technology Commission system can get it, you will give priority to calling it!"

Ding Gaoheng made a judgment in the flash of lightning——

Strengthen investment in die forging presses, it’s worth it!

That’s pretty much it for talking about the important things.

He originally wanted to stay with Chang Haonan for lunch, but when he thought about the other party's recent work arrangements, he decided to put it aside for the time being.

Ding Gaoheng looked at Chang Haonan's back as he was about to go out, then suddenly stopped him and added:

"As for Secretary Lan, just report to me directly. There is no need to submit written materials."

"clear."

…

Similar to the situation with Turbofan 10, the design plan of the die forging press cannot be completely determined at one time.

After the overall research and development route is determined, there are still many specific technical details that need to be optimized.

The technical seminar held by Chang Haonan is precisely to solve these problems.

"Mr. Chang, according to the method you instructed before, we have completed the model construction and meshing of the overall frame of the forging press. The static analysis of the equipment has also gone smoothly and no problems have been found."

Yan Yongnian stood on the podium in the small conference room, pointed at the PPT on the curtain and introduced to Chang Haonan who was sitting at the head of the conference table:

"As you emphasized before, the first ten natural frequencies of the forging press are 0.40618, 0.43178, 0.64196..."

"We checked the data of the same type of die forging presses abroad and found that the frequency under working conditions is around 0.3, and there is no risk of resonance..."

"Wait a moment."

At this point, Chang Haonan suddenly raised his hand and signaled Yan Yongnian to pause:

"Of course it's okay to refer to mature foreign data for analysis, but it shouldn't be difficult for us to calculate this working frequency ourselves, right?"

"Although I have no objection to the value of 0.3, there are some things that are best done by yourself."

Facing Chang Haonan's question, the nearly fifty-year-old full professor of Qinghua University felt a sense of oppression for the first time.

He raised his hand to wipe the non-existent sweat on his forehead, and then explained in a weak voice:

"This is the problem we are facing now."

"After the static calculation, the original plan was to calculate the stress distribution of each structural member under working conditions, but we found that it was difficult to perform a stress analysis on the local composite load-bearing structure."

"Our meshing was done using hexahedral elements on TORCH Multiphysics software. However, during the calculation process, the calculated local stress was always too high. This indicates that the force flow is unevenly transmitted between the combined load-bearing components. On the other hand, it also shows that the deformation between the contacting bodies is uncoordinated..."

"Considering that fatigue damage is the main reason for the failure of heavy equipment, this problem must be quite fatal. If not solved, it can easily lead to gaps in the contact interface between components that come into contact with each other after being subjected to load, which will be fatal to the equipment. destroy……"

"So we must first complete the optimization design, and then start calculating the dynamic data under working conditions, otherwise the calculated results will be meaningless..."

In fact, if we were able to determine the specific location of the problem in such a short period of time according to our previous work habits, it would be a pretty good achievement.

But in Chang Haonan's case, Yan Yongnian was nervous until the end of his explanation.

"The parts that are in contact with each other are slit..."

Chang Haonan looked at the equivalent stress diagram of the C-shaped plate and the cross-key on Yan Yongnian's PPT, lowered his head and made a note on the paper in front of him.

"In other words, there should be a problem with the modeling of the interference connection structure?"

Yan Yongnian and several other subsystem leaders looked at each other, and then nodded:

"It should be that the contact between the various components of the die forging press is a three-dimensional contact problem, and there are uncertainties in the mechanical conditions of the contact surface. We have tried to use the test-error method to iterate normally, but the calculation efficiency is very low, and the convergence is not yet Difference……"

Obviously, they have thought and worked hard.

It just failed.

Chang Haonan's eyes were fixed on the computer screen, which was the setting program for calculation by Yan Yongnian and others.

Stress is not concentrated. If it is a manufacturing problem, let’s talk about it. If it is a design problem, it is definitely a huge hidden danger.

After a period of silence, Lin Qingsong, who was seconded from the Northern Vehicle Research Institute, spoke again and explained:

"This is the most difficult problem in the entire design plan. If Mr. Chang can bring a solution to the next meeting, the subsequent optimization part should be very efficient."

"No."

Chang Haonan still didn't raise his head, just waved his hand:

"No need for another meeting."

"There are generally four solutions to this problem. As for which one to use, you can evaluate it yourself."

"ah?"

Lin Qingsong, who just wanted to find a place for Yan Yongnian to get off the stairs, was immediately stunned.

These are not the four ways to write the word fennel. You can know it by reading more books, but it is of no practical use yet.

The problem of weak point cracking caused by uneven stress distribution is a huge problem not only in China but also around the world.

Under normal circumstances, if the impact is not particularly large, you can only bite the bullet and replace parts more frequently.

Anyway, fatigue damage is not unusable in the first place, it is just a matter of lifespan.

And if the impact is large, then generally only targeted reinforcement will be needed.

Including Lin Qingsong's own job, heavy vehicle design, he also faces a similar situation.

Each time it takes several years, or even longer, to slowly test and solve.

As a result, Chang Haonan came up with four solutions...

Chang Haonan signaled Yan Yongnian to return to his seat first, then walked to the podium, picked up a pointer and pointed at the equipment model on the curtain:

"In the working state, a small closed-loop force cycle is formed in the upper part of the forging press by the C-shaped plate, cross key, large tie rod, and clamping beam. During the forging process, the force generated by the hydraulic cylinder acts on the upper plate beam and then It is passed to the C-shaped plate, then passed to the large tie rod, clamping beam, and finally returned to the C-shaped plate through the cross key.”

"So, the most important part here is the cooperation between the cross key and the C-shaped plate. The contact state between the two will not only affect the characteristics of the force flow transmission, but also affect the deformation of the whole machine in all directions. Influence."

"So the key point is to have a gentler transition in the combined structure so that stress and deformation can be transmitted smoothly and harmoniously."

At this point, he turned back and looked at the dozen or so people sitting below:

"This far, approval?"

Everyone's reaction was quick or slow, but basically everyone nodded to show they understood.

"So, the solution is accordingly."

Chang Haonan pulled over the blackboard next to him and picked up a piece of chalk:

"First, you can set uneven interference without changing the shape of any component, which will not weaken the strength of the component itself. As for the specific method, TORCH Multiphysics provides a function called 'gluing' , you can glue two parts with different meshes together..."

“Here, as long as the interference setting satisfies Δ(min)=pd(C1/E1+C2/E2)*10^3, where E1 and E2 are the elastic modulus of the contained component and the containing component material respectively. quantity……"

"The second is to modify the shape of the contact surface between the cross key and the C-shaped plate based on the force flow analysis I just conducted to reduce the displacement of the two components under pressure..."

"Third, the gapping problem just mentioned is actually due to the additional moment generated by the preload force and the reaction force of the main cylinder. It can be considered to modify the lower part of the wedge key into a shape with a certain slope. To balance this additional moment..."

"The idea of ​​the fourth method is similar to the third one, but it is implemented by changing the component structure..."

On the stage, Chang Haonan's thinking became more and more clear.

In the audience, everyone also followed his train of thought and wrote vigorously.

Of course, as I write, I have to write very hard.

The idea can only be revisited later when we go back.

It wasn't until two blackboards were filled that Chang Haonan finally explained the four solutions he had just thought of.

He turned around, originally wanting to ask everyone what they thought.

But looking at her frowning and thinking, or her confused expression, the question was not asked after all.

There are some things that would be impolite to say.

Fortunately, the people who can sit here are not ordinary people.

The reason why I couldn't follow the train of thought for a while was just because he spoke too fast and too jumpy, not because I really couldn't understand it at all.

If you go back and review more, you will always understand.

"Mr. Chang, why are you so skilled..."

A slightly younger technician looked at his notebook in front of him and let out a long sigh.

Of course, Chang Haonan couldn't directly say that I was cheating, so he had to answer after holding it in for a long time:

"Maybe it's because TORCH Multiphysics was designed by me..."