M Yarmohammad Tooski - PhD Student
R Ghajar - Professor, Faculty of Mechanical Engineering, K.N.Toosi University of Technology, ۱۹۳۹۵- ۱۹۹۹, Tehran, Iran
S. M. R Khalili - Professor, Faculty of Mechanical Engineering, K.N.Toosi University of Technology, ۱۹۳۹۵- ۱۹۹۹, Tehran, Iran

In reality, a tool drop on structure is a repeated impact phenomenon, in which the impact energy is gradually reduced by time in successive impact. In this study, tool drop is experimentally investigated on Glare 3 and Glare 5 plates with the stacking sequence of [Al/0/90/Al/90/0/Al] and [Al/0/90/90/0/Al], respectively. In tool drop, the impact energy is the rebounding energy of the previous impact. Repeated impacts are conducted using dropped weight equipments and force-time and force-displacement results are obtained. It is observed that only the first impact influences the plate for the repeated impact of the tool drop since the impact energy is reduced in successive impacts and no effects can be observed significantly for damage area and type. In other words, in tool drop on Glare 3 and 5 only the first impact is important.

Repeated impact; tool drop; GLARE; damage; C-Scan