The team developed the world's largest three-dimensional spherical three-dimensional weaving machine. The pictures in this article are all provided by the Sun Yize team of Donghua University
The 2022 Beijing Winter Olympics is about to open, and an exciting torch relay ceremony is underway. Spinning and rising, like a ribbon dancing and floating, turning into a roaring flame at the top... As soon as the Winter Olympic torch "flying" was unveiled, it attracted countless attention.
The surging news reporter learned from Donghua University that the Sun Yize team of Donghua University is the key manufacturing technology provider of the outer ribbon (shell) of the torch. The excellent innovation team of the Ministry of Education and the "Education Pioneer" team of Shanghai led by Professor Sun Yize have long been committed to the scientific research and teaching of textile equipment and control, and led the team to tackle the weaving technology of the outer ribbon of the torch.
The torch "flying" production scene of the partner Huai'an base.
International leading three-dimensional weaving technology, "weaving coat" for the torch
The outer streamer shape of the torch "Flying" is very special, it is a high-dimensional surface body, which is an extremely complex heterosexual structural part for engineering manufacturing. "High-tech materials", "high-tech equipment" and "high-end manufacturing", Sun Yize used three "high" words to summarize the "black technology" behind the torch.
In August and September 2020, Shanghai Petrochemical, the overall bearer of the torch, found Sun Yize and threw out a difficult problem - how to use carbon fiber composite materials to present the artistic shape of the outer ribbon of the torch with high precision?
Sun Yize first saw the clay sculpture torch work "Flying", which is derived from the artist's inspiration, hand-shaped boutique, to complete digital manufacturing, industrial production, and with high-tech carbon fiber composite woven molding, the first difficulty to break through is mathematical modeling, only mathematical modeling can restore and reproduce beautiful art design works with high precision, making automated digital manufacturing possible.
In order to lay a good "foundation", Sun Yize led the team to the north several times, and repeatedly discussed, revised and polished with the torch shape designer team of the Central Academy of Fine Arts and the relevant staff of the Winter Olympic Organizing Committee. During the Spring Festival in 2021, the members of the research group are still working intensively to test and change the plan, from busy day to night. "The PhDs on the team dreamed several times at night that they were doing mathematical modeling of the outer streamers of the torch." Sun Yize said.
In the end, the team members overcame the difficulties and completed the mathematical modeling with a multidimensional surface fitting intelligent algorithm.
Professor Sun Yize held an academic exchange meeting for the team.
"During the weaving process, there are 14 possibilities for collision of each moving spindle at every moment"
In the production workshop of the cooperative team Huai'an, a ring -- 8-meter-diameter "big guy" is running at high speed, with hundreds of black silk tows interweaving and shuttling, which at first glance looks like "knitting sweaters", and it only takes a few minutes to "weave" a torch coat that is accurate to grams.
Sun Yize introduced that the outer streamer of the torch is flexible and beautiful, but because it is variable diameter, curvature, up and down is not generally thick, the thickness of the surface is not consistent, the traditional manufacturing process can not be realized, and the "big guy" in front of him is the "secret weapon" of "weaving" the torch coat, which is exclusively developed by Donghua University and the world's first three-dimensional high-precision spherical three-dimensional weaving machine for large-size heterosexual structural parts.
This series of weaving machines can weave large-size structural bearing parts such as large aircraft and high-speed railways, and can also weave precision special-shaped structural parts such as propellers, unmanned aerial vehicles, and flare outer streamers. It has a total of 576 weaving spindles, which can weave a maximum cross-section of 500 * 500 mm, which is currently the world's most powerful and largest three-dimensional spherical three-dimensional knitting machine with the largest weaving size. When the equipment is working, in the circular spherical track, 576 high-speed moving spindles constantly change tracks and cross and shuttle at a rapid speed.
"This weaving process can be said to be 'dangerous', each movement spindle has 14 kinds of collision possibilities at every moment," Sun Yize said figuratively, "It's like on a four-lane highway, there are hundreds or even thousands of cars quickly crossing through the traffic, not only high-speed running, but also constantly crossing, inside and outside penetrating lane change running, we can avoid 'traffic accidents' through intelligent calculation and accurate track change control." ”
In order to make these carbon fiber composite materials "obedient" in the weaving process, and at the same time in the industrial production of three-dimensional reduction of the soft and flowing feeling of the outer streamer, Sun Yize led the team to study the control algorithm, wonderful mechanism, track change technology, etc., from theoretical derivation to experimental verification to production practice, repeated debugging.
In addition, the team invented the so-called "eccentric" weaving method, which solved the problem of large curvature and variable density weaving; original double robot collaborative clamping core mold control algorithm to ensure the optimal dynamic performance of large-size special-shaped structural parts weaving under complex stress conditions; developed a single yarn tension whole process digital control technology to achieve constant tension precision weaving; and developed a high-dimensional surface automatic grinding skill operation robot system. Realizing the three-dimensional automatic three-dimensional weaving and automated grinding of the outer streamer belt of the torch, the project technology not only fills the domestic gap, but also takes a leading position in the world.
In the end, Sun Yize's team made the torch "alive" and truly showed the best "flying" state.
"Small torches carry large energy, and we in China have the ability and technology to weave and form high-precision carbon fiber composite materials!" Looking at the picture of the successful transmission of the torch on the TV, Sun Yize said excitedly, "We will use scientific and technological innovation to support the backbone of the big country's heavy equipment!" ”