Class Ii Cascaded System Simplified Model

This paper is based on the summary of the research of ennergy abosorbtion system and type â…¡ structures, and a modified one-dimensional mass-spring model presented by Gao and Yu is carefully discussed in the thesis.In order to find the dynamic failure modes of a chain of Type â…¡ cells and its dependent of the impact velocity, The new one-dimensional mass-spring model presented by Gao and Yu was introduced by our model to omit the influence of hardening plateau. A dynamic-explicit solution method is adopted in our research. Three dynamic failure modes are only sensitive to velocity when the total kinetic energy remains the same for all specimens. Different impact velocities can result the different failure modes. Results show that: The structure collapse from the impact end to the fixed end with lower impact velocity, and the failure mode from the fixed end and impact end with moderate velocity, and collapse which progressive failure mode very random under higher impact velocity.More practical instances are taken over in the article. We take polyurethane foam, a kind of strain-softening cellular structure, as an example, examine impact on a chain of polyurethane foams according to the curve of a unit cel under quasi-static loading. We also employ the dynamic-explicit solution method. Results show that the failure modes of the system is identical in both theoretic analyses and calculations. Therefore, using the compendious model instead of practical model is completely feasible.