Blow-up study of a nonlinear hyperbolic system with delay

This work examines a system of wave equations that feature frictional damping and nonlinear sources. The two equations are affected by constant delay. By demonstrating that there exist solutions with negative initial energy that blow up in a finite amount of time, we prove a blow-up result. Levine's concavity approach is a basis of the proof. Additionally, by estimating the lower bound, we dominate the blow-up time from below.