No abstract

No abstract

A mathematic model is proposed for predicting the dynamic properties of fiber reinforced plastic composites (FRP) with interphase. Dynamic properties mainly include loss factors and elastic moduli. The results of elastic moduli from the present model are compared with other models. Elastic moduli E 11 , E 22 , G 12 , G 23 and loss factors g 11 , g 22 , g 12 and g 23 of FRP are calculated and a study of the effect of elastic modulus E I and loss factor g I of interphase on dynamic properties in FRP is carried out here. In this paper, E 11 linearly increases with E I , but the growth rate is slow. E 22 , G 12 , G 23 increase rapidly for lower value of E I . The longitudinal loss factor g 11 decreases with the increase of E I in the case of g I < 0.0026. But g 11 linearly increases with E I in larger range of g I , g I P 0.0026. On the contrary, transverse loss factor g 22 , transverse shear loss factors g 23 and longitudinal shear loss factors g 12 increase with increase of E I in the case of lower value of g I , but decreases at larger value of g I . And they also show insensitivity to E I at higher value.

The thermoelectric generator (TEG) provides a way to reutilize this portion of energy by converting temperature differences into electricity using the Seebeck phenomenon. Because the figures of merit zT of the thermoelectric materials are temperature dependent, it is not feasible to achieve high efficiency of the thermoelectric conversion using only one single thermoelectric material in a wide temperature range. To address this challenge, this paper proposes a method based on topology optimization to optimize the layouts of functional graded TEGs consisting of multiple materials. The multimaterial TEG is optimized using the Solid Isotropic Material with Penalization (SIMP) method. Instead of dummy materials, both the P-type and N-type electric conductors are optimally distributed with two different practical thermoelectric materials. Specifically, Bi2Te3 and Zn4Sb3 are selected for the P-type element while Bi2Te3 and CoSb3 are employed for the N-type element. Two optimization scenarios with relatively regular domains are first considered with one optimizing on both P-type and N-type elements simultaneously, and the other one only on the single P-type element. The maximum conversion efficiency could reach 9.61% and 12.34% respectively in the temperature range from 25+C to 40+C. CAD models are reconstructed based on the optimization results for numerical verification. A good agreement between the performance of the CAD model and the optimization result is achieved, which demonstrates the effectiveness of the proposed method.