A qualitative numerical technique is presented for identifying chaotic states of a non-linear one-sided constrained one-degree of freedom (1-d.o.f.) deterministic system under a dynamic non-conservative load. Discrete wavelet analysis in its classic and packet versions was used to search for the boundaries of chaotic and non-chaotic solutions. The results obtained were verified by an analysis of the Lyapunov exponents of the investigated system. On the basis of numerical tests, one can state that wavelet analysis may be a fast and reliable tool suitable for searching for the boundaries of chaotic and non-chaotic solutions.