The snowmobile helmet unveiled at the Winter Olympics was independently developed by the Dongguan Institute of Technology team. It is not only safer, and lighter, but also customized.
Snowmobiles are one of the fastest and most entertaining events in the Winter Olympics. The outcome is often within milliseconds, so the hardware requirements are very strict. The snowmobile helmet research and development team led by Li Nan, an associate professor at the School of Education (Normal College) of the Dongguan University of Technology, participated in the research and development of the snowmobile helmet, which has been used in the training of the national team's Winter Olympics. The team uses 3D reverse modeling and lattice structure 3D printing technology and collects athletes' data to customize one-to-one snowmobile helmets to meet the actual needs of each athlete. This carefully "intelligent" helmet has the characteristics of personalization, weight reduction, safety, and so on.
Choice of materials and structures
According to relevant requirements, the helmet requires all accessories and materials to be China's own.
In the use of materials, the outer layer of this self-developed snowmobile helmet is made of China Aerospace T800 carbon fiber material with high strength and excellent anti-collision performance. T800 carbon fiber is a new type of high-strength, high-modulus fiber with a carbon content of more than 95%. Because the material has been carbonized and graphitized, it has the advantages of low density and high strength. According to relevant information, the density of carbon fiber material is lower than that of aluminum, but the strength is greater than that of steel.
The inner material buffer layer of the helmet adopts a 3D printing lattice structure. The microstructure of the material plays a huge role in its ability to absorb shock. It is reported that the research team has undergone tens of thousands of calculations from the selection of the lattice to the matching of the helmet shell and material properties, and finally determined the optimal lattice structure and Material. Using 3D printing (SLS technology) and TPU powder materials, the lattice structure of the snowmobile helmet buffer layer is designed and developed, which is superior to the traditional EPS foam material, and its impact resistance is improved by about 40%, which can resist the helmet when it encounters a collision. various impact forces and better protect the athlete's head.
It is understood that the helmet made of carbon fiber and TPU lattice structure weighs only about 1.1 kg, which is 500 grams less than the helmet used by the national team before, effectively reducing the weight of athletes. At present, this snowmobile helmet has passed GB and ECE certification meets the requirements of the FIS competition helmet, and has been delivered to the national snow team.
3D printing lattice buffer structures using TPU
The lattice structure generally refers to a space truss composed of rods, plates, and other micro-elements that are repeatedly arranged according to certain rules. It has the characteristics of low bulk density, large specific surface area, and high specific mechanical properties. The sandwich structure with it as the core material produces huge plastic deformation due to the dynamic instability of the structure under the impact load and converts it into heat energy, which can absorb most of the impact energy, so it has excellent buffer energy absorption and impact resistance. , so as to play a protective function.
3D printing has a natural advantage in fabricating lattice structures, which can achieve almost any void precision, void fraction, void shape, void size, pore distribution, and interconnectivity. Based on this, the 3D printed lattice structure can make protective sports equipment, which brings new impetus to the transformation and upgrading of helmets, armors, and other protective equipment.
Furthermore, the material of manufacture determines the properties and applications of the lattice. TPU has excellent bearing capacity, impact resistance, and shock absorption performance, and maintains good physical properties such as elasticity and flexibility even at -35 °C. It is widely used in medical and health, electronic appliances, industry, sports, and other fields. At the same time, TPU is also the main elastomer material suitable for 3D printing.
Based on the above factors, the snowmobile helmet team chose TPU as the lattice structure material.
The "Science and Technology Winter Olympics" is a highlight of the Beijing Winter Olympics. Under the guidance of the concept of "Science and Technology Olympics", countless scientific and technological workers have started the "Olympic Science and Technology Long-distance Run". A stage for self-reliance and self-reliance on horizontal technology. As a new technology that has developed rapidly in recent years, 3D printing has also played a major role in the preparations for the Winter Olympics.