准静态及动态载荷加载下聚脲材料的力学性能

The changing law of mechanical properties of polyurea material under quasi-static and dynamic loading are studied.The polyurea material was stretched and compressed to obtain the stress-strain curve of the material by using an universal material testing machine and Hopkinson bar, and then the impack test of Hopkinson bar was conducted. The results show that the tangent modulus of polyurea material increases approximately exponentially with the increase in strain rate under quasi-static loading, and decreases approximately linearly under dynamic loading. As the strain rate increases, the strength (tensile strength and yield strength) and fracture energy of polyurea material gradually increase.It is concluded that the polyurea material has a significant strain rate effect, and the "decreasing hardening" characteristics of polyurea material under high strain rate loading are closely related to the anti-knock and impact resistance properties of polyurea. From low strain rate to high strain rate loading, the polyurea material transitions from a rubbery state to a glassy state, and its strength is significantly enhanced.