Abstract: The reflection coefficients of the discrete local transmitting bound ary(DLTB)and the superposition boundary(SB)in modeling anti-plane and in-plane wavemotions are studied.The effects of both space and time discretizations on wave motion andthe infiuence of the reflected wave on the coefficients are considered.One-dimensional finiteelement discrete model is adopted in discussing the variation of reflection coefficient withthe order of the corresponding boundary.It is shown that the DLTB is more accurate tha...