Ultrasonic Detection of Spall Damage Distribution Subjected to Plate Impact Test with Different Thickness

¹ Meijo University, Department of Vehicle and Mechanical Engineering, 1-501 Shiogamaguchi, Tempaku-ku, Nagoya 468-8502, Japan
² Nagoya Institute of Technology, Department of Mechanical Engineering, Gokiso-cho, Showa-ku, 468-8555 Nagoya, Japan
³ Oshima Collage, National Institute of Technology, 1-1091 Komatsu, Suo-Oshima, 742-2193 Oshima, Japan

^* Corresponding author: nisimura@meijo-u.ac.jp

Published online: 7 September 2018

Abstract

Plate impact test on medium carbon steel were carried out to the target plate by impacting the flyer plate with one-third and two-thirds thickness of the target plate. The spall damage within the target plate was evaluated non-destructively with a low frequency scanning acoustic microscope as well as ultrasonic velocity and backscattering intensity. We observed the spall damage distribution by the B-and Cscan images. The distribution of spall damage through the plate thickness depends on the tensile stress area within the target plate. The difference of spall damage distribution was investigated by the plate impact test by flyer plate with different thickness. In the plate impact test by the flyer plate with 1/3 target plate thickness, the spall damage was generated by tensile stress area which superposed in the back surface side. On the other hand, in the case of 2/3 target plate thickness, the spall damage was detected at the impact surface side. By generating the spall damage in the different position through the target thickness, it will be possible to evaluate the accumulation of spall damage by reflection and transmission of the stress wave at the internal damage subjected to repeated impact.