The objective of this study is to investigate the detrimental effects of a flexible linear shaped charge (FLSC) to variable thickness back and constant thickness front plates due to varying backspace distance. A FLSC is used to cut both metallic and non-metallic material, quickly and efficiently. It is flexible and may be formed to produce cuts of many configurations, thereby making it particularly useful where more conventional cutting techniques are difficult to employ. While performing its function, the FLSC gives some damage to the back due to the high transient pressure and fragmentation effects. In order to decrease this damage, a steel plate is placed behind the FLSC. In this work, a numerical analysis is carried out by using Autodyn Hydrocode for the investigation of the extent of the plastic deformation of the back as well as front plates for varying backspace distance of the steel plate having different thicknesses. The numerical results are then compared with the experimental findings. The flexibility property of the FLSC is not used in this study. Only the straight segment of FLSC is used.