Xia Yangjie didn't know what kind of madness he was smoking, he had been sitting on the cold bench for four years, and he was still so impulsive. Just now I heard a few words of discussion from several teachers in the teaching and research department who had just returned from a meeting, and Xia Yangjie chased him out with his notebook.

Xia Yangjie graduated from a prestigious university in China four years ago and was assigned to teach in the Department of Chemical Engineering of Pudong Jiaotong University. He didn't originally study polymer chemical engineering, but mathematics. The reason why he came to the Department of Chemical Engineering is ridiculous, that is because the female teacher who used to teach mathematics in the Department of Chemical Engineering gave birth to a child and could not attend classes for two months, so the leader of the Department of Chemical Engineering asked for a mathematics teacher to fill her shortage, so Xia Yangjie, who had just graduated, was assigned.

Xia Yangjie is not a nerd, but he is really lacking in talent when it comes to lecturing. In his opinion, jumping from one formula to another could not be easier, and there is no need to list the detailed derivation process at all. But when he used this way of thinking to teach, his students were failing in large numbers.

The head of the department talked to him several times, and went to the classroom to listen to his lectures, and finally decided that this person was not a teacher of mathematics at all. Fortunately, at this time, the female teacher who gave birth to the child had returned from maternity leave, and Xia Yangjie was gloriously laid off with deep regret and incomprehension.

After research, Xia Yangjie was transferred from the public teaching and research department to the polymer teaching and research department, and undertook the work on the research of fiber winding model.

Filament winding is a kind of composite material production technology that appeared in the 40s, simply put, it is to wrap the fiber soaked in resin to a core mold one by one according to a certain law, and after the resin is dried, take off the core mold, you can get a fiber resin product.

The principle of fiber resin is a bit like the reinforced concrete we usually see. Resin is equivalent to cement, and the fibers in it are equivalent to steel bars, which can play a role in improving the strength of the material. The most common fiber resin is fiberglass, which is a plastic product reinforced with glass fibers.

In addition to glass fiber, the fibers used in filament wound products include aramid fibers and carbon fibers. Filament winding technology can be used to manufacture pipelines, pressure vessels, solid rocket engine shells, etc., and is a new material technology in the ascendant.

As early as the end of the 50s, China has begun to carry out research on fiber winding technology. At that time, it was mainly to serve the needs of cutting-edge national defense science and technology with two bombs and one satellite. In the seventies and eighties, China has introduced a number of fiber winding equipment from West Germany, Italy, Japan, the United States and other countries, and has carried out the relevant work of localization.

The method of filament winding is a bit like the process of winding cotton yarn into spindles in a cotton spinning mill, where the winding mandrel rotates at a certain speed, and the fibers move forward and backward along the shaft, thus forming a circle of winding lines. Xia Yangjie's task in the polymer teaching and research department is to help the teachers who do research in this area calculate the running speed of the mandrel and the speed of the fiber spinning spout to ensure that the winding structure meets the design requirements.

The faculty of the Department of Polymers are all trained in chemistry. The math is not good, so there are some obstacles to calculating such a model. But for Xia Yangjie, who is quite talented in mathematics, this model is as simple as a few differential geometry exercises, and he solves these problems that have plagued everyone for a long time with three strokes and five divisions. What no one expected was that these exercises made Xia Yangjie fascinated by this field and out of control.

The density, angle, overlapping way of filament winding, etc., have a significant impact on the performance of filament winding products. The mechanism of influence is not so much a chemical problem. It's not as much a fascinating math problem. In addition, the traditional filament winding products are mainly convex symmetrical rotators, and for asymmetrical products, or the so-called double-concave rotators, how to realize the winding process is also a subject that requires a lot of space calculations. All these topics. all made Xia Yangjie feel endlessly fun.

After completing the tasks assigned by the department, Xia Yangjie began to conduct his own research. He introduced a large number of mathematical concepts into the study of polymers, and proposed a multi-degree-of-freedom fiber winding and laying model, as well as gradient projection method based on Jacobian matrix, weighted least squares method based on SVD decomposition, and closed-loop solution method for inverse kinematics.

In any field. A person who is one step ahead is a genius, and a person who is a dozen steps ahead is a madman. Xia Yangjie's research on the theory of filament winding is not only more than a dozen steps ahead of his peers, but the result is that no one cares about it.

In the entire polymer teaching and research department, no one knows what Xia Yangjie is doing, and the differential geometry equations he wrote can't be understood by anyone except himself, and they don't know what the effect of this thing is. Xia Yangjie couldn't find a colleague in the teaching and research department who could discuss the problem with him, so he wrote an article to submit, and the editors of the editorial department didn't know whether he wrote it correctly or not. For four years, he didn't even publish a single paper. So in the eyes of the department leaders and colleagues, he became a waste who didn't learn and didn't know how to use some mathematical formulas to pretend.

This time, Qin Hai and Lu Xiaolin came to the Department of Chemical Engineering to hold a seminar, and the academic secretary also notified Xia Yangjie to attend the meeting, but Xia Yangjie had already been cold about this kind of meeting, and he didn't think that the bureaucrats from the government could understand his theory. Besides, he himself is not very popular, so why bother to join in the fun? So, during the meeting, he stayed in the department by himself, deducing formulas that only he could understand.

The teachers of the teaching and research department were ridiculed by Qin Hai at the venue, and they were all disgraced and speechless. After returning to the teaching and research department, everyone talked about the setbacks they had suffered today, and in addition to the indignation, some people felt their conscience and said that Qin Hai's knowledge was indeed extraordinary, and some of the research directions he proposed were really a little inspiring to him.

During this period, a teacher who had a decent relationship with Xia Yangjie on weekdays knocked on Xia Yangjie's desk and said to him casually: "Xiao Xia, it's a pity that you didn't go today." If you go, maybe you will give the little young man of the localization office to the town. ”

"What do you mean?" Xia Yangjie pushed the myopic glasses on his nose and looked up puzzled.

"Today, the localization office came to a very good young man, and he degraded all of us. I pondered, we can't understand the things you usually do, and if you tell that young man, maybe you can make him confused, at least we won't be wiped out. The teacher said half-jokingly.

In fact, what he was thinking in his heart was something else, he hoped that Xia Yangjie could also participate in this meeting, and he would also be degraded by Qin Hai, so that his psychology would be balanced. The ancients said well, good things should be enjoyed by yourself, and when you are unlucky, you should pull others together, this teacher has always been very advocating for such ancient teachings.

Xia Yangjie didn't think about it so much, he just asked strangely: "What kind of young man can degrade our entire teaching and research department, what did he say?" ”

The teacher picked out important content and introduced a few words to Xia Yangjie, and said, "By the way, Xiao Xia, aren't you doing some fiber winding?" I see that among the topics they listed, there is also a problem with the free-form filament winding process, why don't you try it? ”

"Free-form filament winding?" Xia Yangjie's eyes lit up, "Did they really say that?" ”

The teacher threw the materials sent out at the venue in front of Xia Yangjie and said, "Look at it yourself, I don't understand this field, I don't know if what they said is right." ”

Xia Yangjie flipped through the information and saw the problem mentioned by the teacher at a glance, he read the explanation and requirements of the problem twice at a glance, only to feel that his heart was hot, and he stood up.

"Teacher Hu, where are they?" Xia Yangjie asked.

The teacher surnamed Hu pointed with his hand and said, "Teacher Qian sent them out, this should not be far away." What, Xiao Xia, are you really going to find them? ”

"I ...... I ......" Xia Yangjie snorted twice, not knowing what to say. He smiled apologetically at the teacher surnamed Hu, then took out a notebook from the drawer, held it in his arms, and rushed out of the teaching and research room.

"Lao Hu, what's wrong with Xiao Xia?" Someone noticed Xia Yangjie's strange appearance and turned back to the teacher surnamed Hu and asked.

The teacher surnamed Hu said with a smile: "I just told Xiao Xia about the things at the meeting, Xiao Xia probably chased the two young people from the localization office." ”

"Ha Luha, I think Xiao Xia and them are quite compatible, and they are both a bit unattainable." One teacher commented sourly.

"You can't say that, people call it high and low, but you don't have the level of appreciation, and you can't hear the elegance." Another teacher said in an equally odd tone.

"Hehe, it's indeed high and low. However, I'm still better at my lower riba, and we can't get the stuff of spring and snow. The teacher in front of him said leisurely. These intellectuals of the older generation have very good knowledge of ancient literature, although they are a group of people who are engaged in chemistry, and they are no strangers to allusions.

Xia Yangjie didn't know what others were talking about him, and even if he did, he wouldn't care, because in the past few years, he had heard a lot of such comments openly and secretly. He ran out of the office building, went outside, raised his eyes in the direction of the school gate, and saw two young people who were obviously dressed differently from the school's teachers and students walking out side by side, and hurriedly chased after him. At this time, Qin Hai and Lu Xiaolin heard the footsteps behind them, they both stopped and looked back, and Xia Yangjie asked out loud: "Excuse me, are you two from the Pusang Localization Office?" ”

"Yes, we are localized, may I ask ......" Qin Hai asked quietly.

"My name is Xia Yangjie, I am from the polymer teaching and research department of the Department of Chemical Engineering, I am studying the theory of fiber winding, but I am ashamed that I have no achievements. I would like to ask, do you really want to do research on the free-form filament winding process? Xia Yangjie replied upside down. (To be continued......)

PS: This chapter is the one at eight o'clock in the morning, and I didn't expect it to be so difficult to write...... Filament winding is a very complex and complex problem, and reading a paper is almost stupid for an orange. I hope that the concepts in the article are not written wrong, and as for the accuracy, then it is exempt. The most rear...... Ask for a monthly pass.