Title : Stochastic aeroelastic response of variable stiffness laminated composite plates
Abstract:
The influence of uncertainty in material properties on free vibration and the aeroelastic response of variable stiffness composite laminated plates is investigated in this work. Free vibration analysis is conducted by a finite element model based on third-order shear deformation theory. The developed finite element model is further coupled with MSC.Nastran to carry out aeroelastic analysis of variable stiffness laminates in the subsonic regime. MSC.Nastran helps to extract the aerodynamic influence coefficient matrix at discrete values of reduced frequencies using the Doublet Lattice Method. The implementation of variable stiffness laminates in the aerospace application can be helpful to reduce the structural weight, but the alteration of mode shapes due to stiffness variation with a plane of the lamina may cause the two modes to come closer and could be the reason for aeroelastic failure. Moreover, during the complex manufacturing process of variable stiffness laminates, free from any sort of variation in the composite properties is quite impossible which may further deteriorate the structure performance, and probably enhance the chance of early failure of structures. Thus, to investigate the stochastic free vibration and the aeroelastic response of the variable stiffness laminates, the highly efficient radial basis neural network-based surrogate model is developed. The accuracy and adaptability of the developed surrogate model are checked by comparing the result with that of the Monte Carlo simulation. Stochastic analysis of natural frequencies and flutter characteristics of variable stiffness laminates are conducted through various parametric studies. Variance-based sensitivity analysis is used to calculate the contribution of individual material properties to the free vibration and aeroelastic response of variable stiffness laminates. Further, the influence of the highly sensitive properties on structural failure due to dynamic instability is estimated. This research can be leveraged to predict the probability of failure of the structure at different levels of material uncertainty present in it.
Audience take away:
- We always support the collaborative research culture, so if anyone from the audience is having any interest in a similar domain, please reach us.
- Faculty members can include stochastic and failure probability analysis work to enhance their research domain. These stochastic-based design approaches could provide safer and more reliable design.
- The variable stiffness laminates used in the present work are made up of curved fiber that may provide the same strength with lesser weight compared to traditionally used straight fiber laminates.
- The proper utilization of fiber orientation within a lamina could be helpful to adjust the mode shapes favorably and reduce the chance of aeroelastic failure. Thus, these laminates could be pretty useful for aerospace applications.