【摘 要】
：
The sandwich composites structure with a viscoelastic core is widely used in shipping and high speed train for purpose of reducing vibration and acoustic absorbing, its optimization design is signific
【机 构】
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College of Traffic and Transportation Engineering, Dalian Jiaotong University, Dalian 116028, China
【出 处】
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7th China-Japan-Korea Joint Symposium on Optimization of Str
论文部分内容阅读
The sandwich composites structure with a viscoelastic core is widely used in shipping and high speed train for purpose of reducing vibration and acoustic absorbing, its optimization design is significant to improve the performance.In this paper, the finite element model of a sandwich somposites structure with two cover layer and a viscoelastic core is built, the acoustic response characteristics are performed by used of the direct finite element method(FEM) when the plane acoustic wave is incident on the structure surfaces, then introducing the impedance transmission method, the reflect coefficients are computed, and a optimization model is formulated, the objective function is the weight sum of reflect coefficients in a frequency range,tht structure and material parameters of cover layers and core are chosen as design variables.The feasible direction method is used to optimize the design variables.The example results show that the tkickness and density are decreasing and the elastic modulus is increasing for the incident surface cover layer, the elastic modulus and density is increasing for the transmission surface cover layer and the tkickness is also decreasing;the optimized core parameter show that the non-uniformity characteristic can decrease the acoustic reflect.The absorbent performance has achieved a more improvement in high frequency, a maximal reflecting coefficient reduction is achived in 10000Hz.
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