ANALYTIC SENSITIVITY OF DYNAMICS OF ANISOTROPIC FLEXIBLE FOUR-BAR MECHANISMS TO STACKING SEQUENCES

This work intends to demonstrate the importance of a geometrically nonlinear cross-sectional analysis of certain composite beam-based four-bar mechanisms by using different stacking sequences in all component bars in predicting better and critical system dynamic characteristics. In the sensitivities evaluation of the design variable considered is the layer orientation in the lay-ups of the component bars to find the optimal lay-ups which are suitable for practical applications. The goal of this optimization process is to improve the system dynamic characteristics through searching for the optimal values for the fiber orientation of all component bars in the mechanism, which relics on efficient and accurate calculation of the system sensitivities. A numerical example is presented which illustrates not only the importance of 2-D cross-sectional nonlinearities on system dynamics but also shows the advantages of selecting the well-known stacking sequence of Winckler's system through the behavior of the system as observed by using commercial software (I-DEAS + NAS-TRAN + ADAMS).