Mathematical modeling of longitudinal elastic central blow of non-homogeneous rod system about a rigid barrier is carried out, at not-holding connections. Mathematical modeling is carried out by the exact analytical decision of the wave differential equation by method of Dalamber with the setting of necessary initial and boundary conditions. The rod system consists of a step non-homogeneous rod and a homogeneous rod of constant cross section. Connections with a rigid barrier and between rods are not-holding.
