Shape memory alloy metal rubber(SMAMR)is a novel intelligent elastic damping material which can realize the integration of structure and function.The investigations on the anisotropic mechanical characteristics which ...Shape memory alloy metal rubber(SMAMR)is a novel intelligent elastic damping material which can realize the integration of structure and function.The investigations on the anisotropic mechanical characteristics which depended on shaping craft and working temperature were conducted by quasi-static tests.Comparative experiments indicated that the heat setting temperature affect the elastic modulus non-monotonously but has little effect on the loss factor of SMAMR in both martensite and austenite phases.With the increase of the heat setting time,the elastic modulus of SMAMR monotonously decreases and the reduction of loss factor is unobvious.With the present shaping craft,SMAMR exhibits the anisotropy in moulding and non-moulding directions,which is affected by the heat setting process and working temperature.It was proved that the mechanical properties have approximately linear relationship with temperature during the phase transition process.Due to its temperature-dependent mechanical properties,SMAMR that experiences the heat setting procedure is expected to be used in active vibration control systems with varying temperature-dependent stiffness and damping coefficients to provide superior vibration control performance.展开更多
This paper presents an application of finite element method to study the thermoreg- ulatory behavior of three layers of human dermal parts with varying properties. The investigation of temperature distributions in epi...This paper presents an application of finite element method to study the thermoreg- ulatory behavior of three layers of human dermal parts with varying properties. The investigation of temperature distributions in epidermis, dermis and subcutaneous tissue together with Crank-Nicholson scheme at various atmospheric conditions was carried out. The finite element method has been applied to obtain the numerical solution of gov- erning differential equation for one-dimensional unsteady state bioheat equation using suitable values of parameters that affect the heat transfer in human body. The outer skin is assumed to be exposed to cold atmospheric temperatures and the loss of heat due to convection, radiation and evaporation has been taken into consideration. The important parameters like blood mass flow rate, metabolic heat generation rate and thermal conductivity are taken heterogeneous in each layer according to their distinct physiological and biochemical activities. The temperature profiles at various nodal points of the skin and in vivo tissues have been calculated with respect to the severe cold ambient temperatures. The conditions under which hypothermia, non-freezing and freezing injuries develop were illustrated in the graphs.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 51105022,51101008 and 51211130115)Fan Zhou Research Fund (Grant No. 201104021)
文摘Shape memory alloy metal rubber(SMAMR)is a novel intelligent elastic damping material which can realize the integration of structure and function.The investigations on the anisotropic mechanical characteristics which depended on shaping craft and working temperature were conducted by quasi-static tests.Comparative experiments indicated that the heat setting temperature affect the elastic modulus non-monotonously but has little effect on the loss factor of SMAMR in both martensite and austenite phases.With the increase of the heat setting time,the elastic modulus of SMAMR monotonously decreases and the reduction of loss factor is unobvious.With the present shaping craft,SMAMR exhibits the anisotropy in moulding and non-moulding directions,which is affected by the heat setting process and working temperature.It was proved that the mechanical properties have approximately linear relationship with temperature during the phase transition process.Due to its temperature-dependent mechanical properties,SMAMR that experiences the heat setting procedure is expected to be used in active vibration control systems with varying temperature-dependent stiffness and damping coefficients to provide superior vibration control performance.
文摘This paper presents an application of finite element method to study the thermoreg- ulatory behavior of three layers of human dermal parts with varying properties. The investigation of temperature distributions in epidermis, dermis and subcutaneous tissue together with Crank-Nicholson scheme at various atmospheric conditions was carried out. The finite element method has been applied to obtain the numerical solution of gov- erning differential equation for one-dimensional unsteady state bioheat equation using suitable values of parameters that affect the heat transfer in human body. The outer skin is assumed to be exposed to cold atmospheric temperatures and the loss of heat due to convection, radiation and evaporation has been taken into consideration. The important parameters like blood mass flow rate, metabolic heat generation rate and thermal conductivity are taken heterogeneous in each layer according to their distinct physiological and biochemical activities. The temperature profiles at various nodal points of the skin and in vivo tissues have been calculated with respect to the severe cold ambient temperatures. The conditions under which hypothermia, non-freezing and freezing injuries develop were illustrated in the graphs.
