Abstract: The aim of this paper is to trace the influence of fiber path parameters on frequency property so as to design VAT laminates effectively. Firstly, the parametric finite element model of VAT laminate was established to investigate effect of path parameters on the frequency property, by utilizing the definition of linear variation of fiber angle. Secondly, influences of aspect ratio and thickness of VAT laminate on frequency characteristic were analyzed and discussed based on the periodical distribution of fiber path. Finally, optimization design fiber path of square VAT laminate was conducted under different boundary conditions using sequential response surface method, for maximizing the first order frequency and the difference of first and second order frequency. The results show that the band gap of first and second order frequency of VAT laminates can be effectively improved by the optimization of fiber reference direction angle, which has little influence on the first order frequency. Effect of characteristic length on frequency performance is decreasing with increasing aspect ratio. The thinner VAT laminates, the greater the impact of fiber path on frequency performance. The results provide guidance for frequency performance design of VAT laminates.

Key words: variable angle tow laminate, frequency optimization, fiber path, response surface method