| This thesis focuses on thermoelastic plates and thermoelastic transmission plates with damping and dynamical boundary conditions problem and we proved the expo-nential decay of solutions. The thesis is composed of three chapters, the main contents as follows:In chapter 1, we first introduce some terminologies and notations to partial differ-ential equations and semigroup of linear operators. Secondly, we introduce some theory and formulation to partial differential equations and semigroup of linear operators.In chapter 2, we first give a thermoelastic plates with damping and dynamical boundary conditions. This is a system composed of a thermoelastic plate equation with damping and ordinary differential equation, which is described as follows: Secondly, we can write the above system as an abstract system, then give the result that the corresponding Co-semigroup is exponential stabilization. Thirdly, by using the frequency domain criterion for exponential stability of Co-semigroup in Hilbert space, we prove that the Co-semigroup corresponding the thermoelastic system is exponential stabilization.In chapter 3,we first give a thermoelastic transmission plates with damping and dynamical boundary conditions. This is a system composed of a thermoelastic plates equation with damping and ordinary differential equation, which is described as fol- lows: Secondly, we can write the above system as an abstract system, then give the result that the corresponding Co-semigroup is exponential stabilization. Thirdly, by using the frequency domain criterion for exponential stability of Co-semigroup in Hilbert space, we prove that the Co-semigroup corresponding the thermoelastic system is exponential stabilization. |