Investigation Of The Heat Conduction And Thermoelasticity For Functionally Graded Material Plates

Functionally Graded Material (FGM) is widely used for its special performance. In this dissertation, the recent developments of Functionally Graded Material about heat problems are briefly summarized. Hybrid Numerical Method (HNM) and Strip Element Method (SEM) are applied to heat conduction and thermoelastic problems of FGM plates. This is the extension and exploitation for two methods and provided a new way for investigating heat effect of FGM plates.The HNM has been widely applied into the displacement response of composite laminated plates. We apply HNM into heat conduction analysis of FGM plates. The formula of heat conduction of HNM is deduced. On the basic of heat balance equation of FGM plates, different methods are used in the different directions. The solutions of heat conduction problems are obtained by method of weighted residual. Using HNM the Heat conduction problem of FGM plates, been composite of ceramic material ZrO 2and metal material Ti-6Al-4V , are analysed. The material properties of the FGM plates are assumed to vary linearly in the thickness direction. Heat conduction of the plates is analysed for continuous action and transient action of the heat source and the temperature distributions of FGM plates in different time and different position are obtained. The HNM applied to heat conduction not only extends the application region of this method but also provide a new study way for heat conduction problems.HNM is further applied into thermoelastic analysis of FGM plates. The thermoelastic formula of HNM is deduced. On the basic of balance equation of FGM plates, Different methods are used in the different directions. The solutions of thermoelastic problems are obtained by the principle of virtual work. Using HNM thermoelastic problems of FGM plates, been composite of stainless steel and silicon nitride, are analysed. The material properties of the FGM plates are assumed to vary linearly in the thickness direction. The thermoelastic problems are analysed for continuous action and transient action of temperature change source. The displacement responses of FGM plates in different time and different position are obtained and stress wave are also investigated. Applying HNM into thermoelastic problems is further studying based on heat conduction and provides a new way for studying the thermoelastic response.SEM is developed on the basic of HNM. The SEM has been widely applied into the displacement response of composite laminated plates. SEM is applied into thermoelastic problems of FGM on the basic of ever done. On the basic of balance equation, the formula of thermoelastic problems of SEM is deduced. The general solution of thermoelastic problem is obtained by the principle of virtual work. The general solution is formed by two parts: particular solution and complementary solution.Thermoelastic problems of infinite FGM plates are analysed using SEM. The thermoelastic response distributions of FGM plates are obtained. The same thermoelastic problem is analysed using HNM and SEM, respectively. The connection boundary conditions have been verified correctly by varying different connection position.The thermoelastic problems of FGM plates with horizontal cracks and vertical cracks are also investigated using SEM. The influence of different character cracks to the thermoelastic response is investigated by studying the displacement response. Different thermoelastic response are deeply analysed by considering different conditions, such as, varying the distance of cracks from heat source, different length of crack and different frequency of heat source. The method of identifying the character of cracks by investigating thermoelastic displacement response is proposed. Thermoelastic response method can be used to detect the character of the system while it has difficulty to apply force response to the system.