SMSE Professor Jingtao Han and his Team Contribute to the Successful Launch of the Electromagnetic Monitoring Satellite “Zhangheng-1st”
Xinhua News Agency reported that on February 2nd at the Jiuquan Satellite Launch Center, China successfully launched the Electromagnetic Monitoring Satellite “Zhangheng-1st” attached to the Long March 2 D rocket, after which the satellite entered orbit according to schedule. A large deployable boom system, which was invented and manufactured by SMSE Professor Jingtao Han, was used as the main implementing mechanism to enter outer space and undertake the task of sending multiple payloads carried by satellites. Whether or not the space deployable boom system can efficiently and reliably send these sensors to designated locations in space is the ultimate and most crucial step in the success or failure of spacecraft launch missions. When satellites are in orbit, to complete the detection of electromagnetic signals and other signals in space, it is necessary to extend the detection equipment to a position away from the star. Due to restrictions of the launch vehicle and satellite structure, it is difficult for the satellite body to meet the requirements of gravity gradient stability and inertial characteristics. Therefore, by using the deployable boom system, the ground satellite tool will be compressed to a very small space for the detection instrument, as shown in Figure 1.
Figure 1.
After the satellite enters orbit, the end mass (such as the balance dynamic damper, electromagnetic field detection instrument, etc.) is extended to the outer end of the body away from the body by the one-dimensional elastic stretching rod mechanism, allowing for the earth's electromagnetic field and other parameters to be detected. The working status of the elastic extension mechanism on the satellite is shown in Figure 2. The elastic deployable boom system is the core part in a satellite with payload, and the space stretch system of the satellite equipment of Zhangheng 1st consists of six deployable boom systems. The successful development of such elastic strut mechanism has great application and promotion value.
Figure 2.
The newly-developed elastic deployable boom system is self-driven, light weight, has high energy storage, greatly reduces the complexity of the mechanism, and has a high degree of precision. As such, this technology has attracted considerable attention in the international space community and is the object of much contemporary research. At present, China's University of Science and Technology Beijing, the United States HUNTER Corporation, and Canadian Spar Corporation have become the primary R&D and manufacturing centers of these countries. USTB has steadily developed a leading edge in this type of technology and product applications, and events such as the launch of the Zhangheng-1st satellite will enable China’s large-scale space development agencies to take the lead internationally in terms of the number of loads delivered, the accuracy of the deployments, and their overall efficiency.
Having been approached by China’s aerospace agency, in June 2013 Professor Jingtao Han’s team began working on various projects including the principle design of the rod extension mechanism, material development and finalization, theoretical research of the forming process, equipment technology research, equipment design and manufacturing to gradual transformation and optimization, sample prototype improvement, and the formation of industrial production. After nearly 80 experiments in simulated-space conditions, the China National Aerospace Science and Technology Corporation was ready to launch the Zhangheng-1st rocket, and its successful launch proved an invaluable milestone in USTB’s ability to fully manufacture and equip the spacecraft with the required deployable boom system. At present, many spacecraft, such as the Tiangong-IV, have been equipped with unfolding systems manufactured by USTB, and are waiting for delivery. Meanwhile, Professor Jingtao Han’s team is currently conducting further research work on the development of the two-dimensional space deployable system for Solar Sail spacecraft (expected to land on Mars in 2020), as well as on the design of the China Aerospace Station project.
Han Jingtao’s research profile:
The team of Professor Han Jingtao from University of Science and Technology Beijing is a major influence in the field of plastics processing at materials engineering fields. It has long been rooted in production and serves the construction of the national economy.
In the country's major technical equipment field, in 1995, Professor Jingtao Han proposed the theory of self-healing theory of cracks in metallic materials, which has caused major international repercussions and has become a research hotspot in international academic fields. According to the theory, Professor Han proposed the controlling crack forging process for heavy forgings, such as heavy cakes, heavy modules, heavy shafts, heavy flanges, and heavy barrels forgings, solved the problems of forging cracks that have plagued large forgings for a long time, and made the qualification rate of large forgings in China rapidly jump from 44% to more than 98%. This progress has made possible the economic and reliable manufacturing of large and super nuclear power forgings, thermal power forgings, hydrogenation reactors, and other heavy forgings, laying an important foundation for the rapid and stable development of China's key equipment manufacturing industry.
In the field of high-speed railway technology, before the mid-1990s, China's railway passenger and freight mixed-line operation, the maximum speed of train traffic could not exceed 120Km / h. If the train exceeded the speed limit, cracks around the hole in the web of a conventional perforated train wheel would be cracked. In order to increase the speed, developing a solid web wheel was needed. In 1996, Professor Han’s team undertook the task of developing process technology for the “Production Line for speed-raising and high-speed railway wheels” project of the national “Ninth Five-Year Plan” key project, in which he was responsible for forging, rolling, heat treatment and other hot-wire process development, and the design and manufacture of wheel rolling mills. The theory of progressive forming of roulette parts and the theory of misaligned rolling of ring discs were proposed creatively. The theory and process of China’s train wheel rolling were formed and successfully applied through production practice. Jointly with the research team of Taiyuan Heavy Machinery Group, Professor Han’s team built the first solid rail train wheel production line in China, which showcased the development and application of China's railway speed-raising trains and high-speed train wheels. In the end, Professor Han’s team laid a solid theory for the speed-up of China’s railway system by a factor of seven.
Before 1997, China’s stainless steel industry was vastly underdeveloped, and the total amount of stainless steel plate production in the country was less than 30,000 tons/year. In order to completely change this situation, the National Planning Commission launched the National Science and Technology Innovation Program “High-Quality Stainless Steel Sheet Technology Development” and built a 300,000 ton/year high-quality stainless steel sheet production base at TISCO. Professor Han led a team from the University of Science and Technology Beijing to participate in this project. He was responsible for technical developments in smelting, hot rolling, cold rolling, pickling, and annealing processes. He inspected and learned of the technical work of international advanced stainless steel production lines, production line designs, and selection of key equipment. The 20-roll mill plate type control theory and process technology, together with the team of Professor Yide Wang of Taiyuan Iron and Steel Co., Ltd. and Professor Xifan Kang of the Iron and Steel Research Institute, all came together to contribute to the historic breakthrough of 30,000 to 300,000 tons of high-quality stainless steel plate production in China.
In the field of advanced laminated materials, in 2004 Professor Han proposed the Z-U-X theory on the interface of composite and laminated materials and developed the “Centrifugal Casting Composite Billet + Hot Extrusion Forming + Cold Rolling/Pull Forming” process to manufacture a full metallurgical laminated bimetal tube. He utilized new technology and cooperated with emerging Jihua Group and Panzhihua Iron and Steel (Group) Company to produce more than 40 series of bimetallic laminated pipes such as superalloy/carbon steel, stainless steel/carbon steel, high carbon steel/common carbon steel, and titanium/carbon steel, among others. The product has become the best double/multi-metal laminated material with the best interfacial performance in the world. At present, it has been promoted to be used in important national economic fields such as petroleum, chemical and military industries, and as such has produced tremendous economic benefits. The results of this project were reported by CCTV’s “Great Power System” on December 13, 2015. On the basis of this, Professor Han’s team has developed dual metal laminated plate technology, large deformation high chromium cast iron material technology, 6.5wt% silicon steel technology, SUS304BN series nuclear shielding material technology, high-performance multilayer bulletproof material technology, and high-performance laminated gun/barrel material technology, with all these technologies sharing the common feature of being easy to apply as the main equipment of existing steel mills, as well as being readily available for large-scale industrial production.
In the “One Belt One Road,” “Urban Comprehensive Pipeline,” “Sponge City Construction” and other national strategic areas, since 2004 Professor Han’s team has systematically researched and promoted corrugated steel pipe technology in China. Subsequently, corrugate steel pipe technology has been adopted for projects such as China's “Belt and Road” infrastructure construction, urban comprehensive pipe gallery, “sponge city” construction, and military engineering construction. Regulation GB/T34567-2017 and other series of national, industry and local standards have caused tremendous social impact, putting corrugated steel products at the forefront of steel deep processing products, thus creating an emerging market of about 26 million tons/year for the Chinese steel industry.
In 2012 Professor Han proposed the concept of “cold and hot coupling forming technology” and its application methods, which solved the forming problems of high-strength, thick-walled, and complex-section steel products and developed many new deep-processed steel products that have played an important role in the development of the national economy. Among them, in the field of lightweight vehicles and vehicles, high-strength steel can greatly reduce the overall quality of the carrying equipment, improving the carrying capacity and safety of the equipment, and reducing the transportation energy consumption. As such, Professor Han’s work in this field is at the forefront in terms of research and development. However, the poor plasticity of high-strength/ultra-high-strength steels and their difficulty in forming become the main technical obstacles to their development and application, and the market is difficult to develop. In addition to China, the global market for thermoformed steel plates is only 300,000 tons/year. The 1500~2100MPa hot and cold roll coupling forming super-high-strength shaped steel pipe developed by Professor Han’s team is reliable in process technology and product quality, and has been applied in large quantities to the main components of passenger cars in companies such as Yutong and Jinlong, specifically in the cars’ anti-collision bars and bumpers. Additionally, stabilizing rods and other important structural components will soon become the main structural material for all types of vehicles, and on this aspect alone, the domestic market for ultra-high-strength automotive hot forming steel will soon exceed 100,000 tonnes per year.
In the field of steel structure/prefabricated residential development, the main constraint for the slow development of steel structure technology over the years has been the manufacturing technology of thick-walled (≥6mm) steel components, as the steel plate has undergone significant reductions in the thickness of the steel plate at its roll forming sites. In recent years, the state has vigorously promoted the application of steel structure technology and fabricated residential development, but the rectangular steel tubes that account for more than 50% of the steel used for building structures, especially the thick-walled square rectangular steel tubes used as the main bearing members, are mostly used in steel plate welding manufacturing, manual operations and welding workload, and such their construction quality is difficult to control leading to post-distortion, high operation and maintenance costs, and serious environmental pollution. In order to completely solve the bottleneck problem of this technology, Professor Han’s team developed a thick-walled, defect-free square-rectangular steel pipe that is known by the construction industry as “outer square/inner round” and is thickened at the corners. Already unanimously approved and praised by construction experts, this new technology advances the epoch-making progress of steel structure technology, and as it is applied in wider fields, will be adding in the near future a ≥ 40 million tons/year market for the Chinese steel industry. At present, the use of medium-thick steel plate as a raw material, the use of similar technology to produce parallel leg angle steel, and parallel leg channel steel (with the same specification products can increase the 20% section modulus), have all been quietly applied to the domestic and foreign steel structure market. Professor Han's team is organizing the preparation of national standards for hot and cold composite forming rectangular steel tubes.
In the field of modern transportation, steel bridges have become the focus of national attention and have been vigorously promoted for their development. It is proposed that the proportion of steel bridges in China should be rapidly increased from less than 1% to more than 30%. However, traditional cold bends such as thick U-ribs caused steel bridges more than 90% of their problems, resulting in a bottleneck that restricts the development and application of steel bridge technology. Through communication with bridge technical experts at home and abroad, Professor Han successfully proposed the concept of thickening roll forming U ribs at the end. A new type of UTU ribs with thickened ends has been developed. The test results of the National Bridge Key Laboratory of Southwest Jiaotong University show that the new UTU ribs can greatly increase the fatigue performance of welded joints and significantly increase the reliability and stability of steel bridges. It has been applied in the construction of nearly 20 large-scale bridges at home and abroad. In the near future, it will add a market of 22 million tons/year to China's steel industry.
Among the research teams of the Beijing University of Science and Technology, Professor Jingtao Han’s team main characteristics are profound theoretical knowledge, long-term adherence to the production line, rich practical experience, and strong hands-on operational capabilities. The team has always taken the major technical issues and major demands of the national economy as its main guiding principle, and such is actively guided by developing new technology, meeting market demands, and forming a series of major original innovations. By serving the industry's long-term development direction and the government’s policy orientation, and sticking to the main premise of national economic development, USTB continues to lead the way in high-quality research work.