Zoghlami, MeriemBrakni, wissal2022-07-182022-07-182022http//localhost:8080/jspui/handle/123456789/4964In this thesis , we study the dynamic proprieties of a nonlinear viscoelastic Kirchhoff-type equation with initial conditions and acoustic boundary conditions (see [29]). We show that , the energy of the solution decays exponentially or polynomially. Our approach is based on integral inequalities and multiplier techniques. Instead of using a Lyapunov-type technique for some perturbed energy .enKirchhoff-type equation, Acoustic boudary condition , Original energy , Energy decayéquation de type Kirchhoff , Condition aux limites acostique , énergie originelle , Décroissance d'énergieمعادلة كیرشوف ، شروط حدیة صوتیة ، الطاقة الاصلیة ، إضمحلال الطاقةThesis