FBG testing on inside strain capturing of concrete blocks subjected to hard projectiles penetration

Abstract

This study evaluates the terminal ballistics and strain behaviors of normal strength concrete blocks penetrated by hard ogival-nosed projectiles. Fiber Bragg Gratings (FBG) sensors are utilized herein to measure the radial strain responses inside concrete target during penetration process. With precise location, a novel method of FBG sensors embedment inside concrete block is proposed. The penetration tests are conducted with ballistic gun whereby the FBG sensor reflected signals are recorded. Consequently, Holmquist–Johnson–Cook (HJC) model is used to describe the concrete material dynamic behaviors. The LS-Dyna numerical penetration model is validated by Depth of Penetration (DOP) prediction. The numerical radial strain inside concrete target matches well with the experimental data by FGB testing.