دانلود رایگان مقاله توالی آسیب حوادث رخدادی در دوره اثر شدید انرژی پایین

Abstract

Finite element simulation was carried out to better understand damage formation in CF/epoxy plate in the course of a low velocity 8J impact. The plate under investigation was of [+30/−30]s lay-up. To validate the numerical results a drop test was carried out with the help of a drop tower. The interlaminar damage extent was determined with the help of C-scan. Comparison between the numerical and experimental results showed a good quantitative agreement concerning contact force time history, however, the amount of dissipated energy determined based on the numerical simulation was lower than that from the experiment,consistently, the damage extent determined based on numerical simulation was smaller than that determined by C-scan. Nevertheless, characteristic points on the plot representing contact force time history could be related to the particular damage mechanism onsets and their actions.

6. Conclusions

Numerical simulation of impact damage evolution in a CFepoxy laminate plate of [+30/30]s lay-up was carried out with the help of FEM. The contact force, displacement and velocity time histories were of interest as well as the sequence and interaction of damage modes, and the damage extent. The numerical results were compared to the experimental ones. For the velocity time history and the rising part of the deflection time history diagrams very good correlation between the experimental and numerical results was obtained, however, for the latter the remaining diagram parts slightly diverged. For the contact force time histories a close resemblance of both the plots i.e. based on experiment and numerical simulation was clearly visible for the initial time period up to approximately 0.0011 s. The most pronounced divergence occurred for 0.011–0.0035 s time window, however a close agreement between the maximum values of the forces was obtain, nevertheless the pick force values were shifted by 0.0003 s, approximately. Good agreement between the experimental and numerical results was regained for the remaining time of the event.