Source: Beijing Daily reporter Ren Min, Tsinghua University

Wechat official account: visual algorithm

“In the college entrance examination, he was admitted to qinghua University as the top scorer in the local science field. In the four years before his doctoral study, the number of his first published papers was zero, his first doctoral proposal was denied, and he received a warning of deferment after graduation defense. In the fifth year of his doctoral degree, he wrote an academic paper and published it in the top journal……”

Dr. Fang Yaopeng, who had been warned to postpone his graduation, once delivered a speech as the only student representative at the graduate graduation ceremony of Tsinghua University. To an audience of tens of thousands, he shared a story of frustration.

Doctor graduate Fang Yaopeng speaks. Photo by Shi Jiadong of Tsinghua University

A warning to delay graduation

Born in 1991, Fang Yaopeng grew up in a fishing village in southern Fujian. Space dream, seems to be his ambition since childhood: hot summer night, lying on the courtyard mat, he took a toy telescope, looking for craters on the moon, often the flashing lights of the plane into an alien flying saucer; In second grade, in science and technology class, he carefully squeezed a space rocket with colored plasticine and displayed it complacently in the window of his living room for years. In the “common sense of astronomy” my father bought, the mystery of the birth and death of the planets fascinated him; In TV drama “the Sea”, the courage that double doctor Ma Jianchang risks his life to develop long wave radio makes him shocked…

In the college entrance examination, Fang scored 679 points in Zhangzhou, Fujian province, and ranked seventh in the province. With this result, tsinghua University all popular major can choose at will, however, he only filled in a major volunteer – engineering mechanics department.

Founded by qian Xuesen, Qian Weichang, Guo Yonghuai and other older scientists at tsinghua University’s Institute of Aeronautics and Astronautics, this major is one step closer to their aerospace dreams.

** After graduation, Fang yaopeng stayed in Qinghua Garden and began his PhD career. ** His research interests are material level instability analysis. The so-called material level instability means that the material can no longer maintain the original stable uniform deformation path when it reaches a certain loading condition during the bearing period. Post-instability deformation often involves severe localized deformation, which may lead to material failure. This research direction is the research category of solid mechanics, and is also the frontier focus of engineering field.

As we all know, classical mechanics has been developing for more than three hundred years since Newton’s three Laws were put forward, especially the theory in the field of solid mechanics has been quite mature. For general doctoral students, it is very difficult to find a breakthrough point in theoretical innovation in just a few years.

After entering the doctoral program, his supervisor proposed to him: “If you pick up the scraps of other people’s research step by step, with a little embellishment, you can produce articles, but soon no one will care about them. This is not the standard for tsinghua PhD students.” ** With academic ambition for scientific research, Fang yaopeng decided to choose more original basic theory research, trying to make his research results have long-term influence and benefit more fields.

PhD in the first two years, in addition to the class, he spent a lot of time reading the constitutive relation of solid mechanics, solid and difficult in the field of literature, read and use the formulas or using a computer programming test, he said with a smile: “table with full all formula is derived, with high school physics, the paper and pencil problem solving.”

When he was in the fourth grade, he suffered a big blow after going through the opening thesis defense like other students.

“In the first four years of my PhD, the number of papers I published as the first author was zero, my first PhD proposal was rejected, and every year I received email applications for scholarships were ignored.”

Fang yaopeng still clearly remembers that in the fall of 2017, after the thesis defense was over, a teacher in charge of graduate management in his department called him over to have a talk: he failed the thesis defense and might have to postpone his graduation. “My heart is very uncomfortable, the probability of failure is very low, every year the whole grade is one or two.” The feeling, for the former top scorer, was “like a good student failing the exam.”

Fortunately, his mentors, Academician Gao Huajian and Professor Liu Bin, gave him the greatest tolerance and support. They encouraged him to be a tough young man: ** Tsinghua students should do first-class academic work and make the results stand in both the time span and the breadth of disciplines.

Difficulty is talent

After reflecting on the pain, Fang Yaopeng also began to reflect, his first three years of knowledge is not strong, there are indeed detours. For example, due to a programming error, the conclusion was not in line with the expectation, and the omission was not discovered until more than a month later. If there are deviations in formula derivation, they will be found wrong from time to time after reporting to the tutor; But in the opening report, he just set up the basic theoretical framework, during which a lot of work has not been carried out. He calmly accepted the fact, “I’m not surprised I didn’t pass the opening.”

Calm down doesn’t mean throw in the towel. In order to avoid delaying his graduation, he began to speed up his progress, often staying up until midnight and occasionally taking a break at two or three in the morning. He spent almost half a day deducing formulas and reading professional books and papers. Gradually, he found that articles that he had struggled with a few years ago became easier to read, and he made fewer programming errors.

Difficulty is to see talent, more than will have.

His mentors, Academician Gao Huajian and Professor Liu Bin, gave him full freedom and provided him with all-round help and support. The long talk with his tutor extended from academic topics to the meaning of life, which helped Fang resolve his frustrations and worries. Faced with scientific problems, Fang yaopeng sought inspiration to solve the problems from previous literatures and his own derivation. Sometimes you try different ways to solve a problem for weeks on end, even in the shower or in your sleep.

After half a year, he finally set up the theoretical framework of a complete system. The second opening defense, he successfully passed.

The fifth year of his doctorate was a year of harvest for Fang Yaopeng. He wrote an academic paper for the first time to give a reasonable and universal measurement of property tensor anisotropy, and was notified by Physical Review Letters, a top physics journal, at the end of 2018. The paper was published online before the Spring Festival. In a subsequent paper, which was published in a special issue of the Journal of The Mechanics and Physics of Solids, he presented a concise general criterion for material level instability and solved the problem of composite and soft material instability.

In April 2019, Fang received a certificate of Excellent academic report at the “Four Universities Aerospace and Mechanics Academic Forum” hosted by Dalian University of Technology. Yang Wei, an academician of the Chinese Academy of Sciences, presented him with the award.

Photo with Academician Yang Wei of Tsinghua University

Upon graduation, he was the first in his group in the pre-defense of his doctoral thesis. In the evaluation before the defense, he got all A’s. What’s more exciting is that in the final defense of his doctoral thesis, some reviewers spoke highly of Fang’s work, saying, “He is very brave to challenge difficult problems and is very likely to break his head and bleed.”

We will continue to tackle key problems in scientific research

Science fiction writer Liu Cixin has said that in the long run, of all the countless possible futures, those without space travel are bleak, no matter how prosperous the earth achieves.

At present, the construction of China’s space station is on the way. However, the key technologies of the space manipulator involved in the on-orbit maintenance, construction and rendezvous and docking of the space station still fall short of the international advanced level.

After experiencing the baptism of frustration, Fang Yaopeng stride forward to dream one more step.

After graduating, Fang yaopeng went to the China Academy of Space Technology (The fifth Academy of Space Science) to do research on a new generation of flexible space manipulator, which is urgently needed by the country. ** Flexible manipulator has broken through many limitations of traditional rigid manipulator, and is becoming the strategic technical highland that all countries are competing for.

“The application of soft materials in flexible space manipulations makes nonlinear large deformation instability analysis particularly critical, which is the focus of my doctoral research,” he told reporters. I’m looking forward to putting what I’ve learned into practice.” In the future, there will be flexible robotic arms that can interact with astronauts inside the capsule and grasp objects without loss outside the capsule to facilitate space experiments. In the field of civil robotics, it has great potential.

In addition to climbing scientific peaks, During his nine years at qinghua Garden, Fang also loved another thing — playing the tuba.

At the graduation ceremony, he revealed his identity, “Every graduation season, I wear the white uniform and play the school song with the marching band.” As a child, Fang yaopeng, who was born in a farmer’s family, had never learned to play Musical Instruments. At the beginning of the semester, when the student art troupe was recruiting new students, he ran to register with enthusiasm. Perhaps moved by the sincerity of the big boy with a Minnan accent, the interviewer left this “little white” with zero foundation. From then on, an elder brother began to teach him to play the tuba hand in hand, once a week, three or four hours at a time, without fail. Fang struggled to survive. He learned to read tuba music and began performing the following year.

It is precisely because of this “little white” spirit that Fang yaopeng can immerse himself in scientific research. After four years of hibernation, in which he did not publish a single paper as a first author, he began a “counterattack” in his fifth year.

This makes Fang yaopeng more confident: as long as there is hard work, the future will still “survive”.