No abstract

Short interval and continuous high-impact experiments have very significant engineering application values, and impact acceleration is a key performance index of these dynamic experiments. This paper aims at the shortcomings of the existing multiple high-impact equipment, designs a new type of multiple high-impact equipment based on the collision contact mode by multiple impact components, and studies the composition of acceleration in impact experiment. The research results indicate that it is unreasonable to analyze the impact acceleration only based on rigid body dynamics theory and ignore the effect of the stress wave loading during an impact experiment. On this basis, a line contact model is adopted to modify the equivalent damping coefficient and obtain a nonlinear spring damping contact force model based on the line contact, and then a rigid body acceleration model of the impact experiment is established. A stress wave acceleration model is also established based on the one-dimensional stress wave transfer theory of the tested specimen. The established acceleration model is verified by different corresponding impact experiments. At the same time, the collision contact process of the impact experiment is also simulated which is combined with the finite element method. The simulation results were fundamentally consistent with the experiments and a fact that proves the correctness of analysis and modeling. The research results not only provide theoretical support for the design and analysis of the impact equipment and a new idea to realize multiple high-impact loading but also provide a methodology to be applied to the analysis and modeling of acceleration for similar high-impact experiments.

No abstract

Oblique deep penetration is a common form of projectile penetration into the target. In view of the fact that most of the research work is focused on the trajectory of vertical penetration, the trajectory and law of oblique penetration are discussed in this paper. This paper studies the impact of different initial angles of attack on projectile trajectory and fuze impact in oblique penetration by simulating projectile penetrating target with LS DYNA software. The results show that with the increase of attack angle, the deflection of trajectory is more obvious, the penetration depth is smaller, and the impact acceleration amplitude of fuze is larger. The research content of this paper provides a reference for oblique penetration of concrete target and impact performance of fuze, and is of great significance for the construction and protection of underground fortifications.