Papers by Keyword: Dynamic Tensile Properties

Abstract: Split Hopkinson bar technique was often used to measure the dynamic mechanical properties of engineering materials. In this paper, the dynamic tensile and compression mechanical properties of polymer explosive bonded (PBX) under different strain rates were obtained by using split Hopkinson pressure/tension bar. The thickness of the specimen and the shape of the incident wave are designed to ensure the rationality of the experimental results. By comparing the experimental results, it was found that the PBX had different dynamic tensile and compression properties. The PBXs have been tested and shown tensile and compressive strengths ratios that range between 5 and 7. A constitutive relation is developed for modeling the dynamic mechanical response of PBX-I by using the Boltzmann superposition principle with a Prony series representation. The parameters of the PBX-I were fitted by using least square method. A finite element model was used to simulate the dynamic compressive and tensile behavior of PBX-I, and the numerical simulation results were in good agreement with the experimental results, which proved that the linear viscoelastic constitutive relation can be applied to the PBX-I.

Abstract: The tensile properties of a titanium alloy reinforced with 3% by volume fraction of TiC particles and of an unreinforced titanium alloy are studied over a range of strain rates from 0.0001s-1 to 1300s-1 using quasi-static material testing system (MTS810) and split Hopkinson tensile bar apparatus. The experimental results show that both the TiCp/Ti composite and its matrix alloy exhibit an obvious strain-rate hardening property. But the high strain-rate sensitivity of the TiCp/Ti composite is significantly higher than that of the matrix. The high strain-rate sensitivity of the TiCp/Ti composite is considered to be originated from the high dislocation accumulation rate during dynamic deformation and the constraint of TiC particles on the surrounding matrix, which dramatically enhances rate of the matrix. Finally, a phenomenological dynamic constitutive relation is established considering the composite is elastic-perfectly plastic material.