Automation of "Ply Elimination" Procedure in HyperWorks for Failure Analysis of Composite Structures

The design optimization of composite structures in the aeronautical and automotive field has identified the need for a more in-depth investigation into the ultimate strength resistance capabilities of the structures, with the aim of achieving weight-saving targets.

The application of the Ply Elimination procedure entails the local degradation of the mechanical properties in the areas where the composite failure criterion is not passed. Subsequent re-analysis of the stress redistribution which arises in the degraded structure provides a more comprehensive assessment of the ultimate strength resistance in areas of interest.

However, the iterative nature of this procedure discourages the user from its manual implementation on finite element models, due to the process being time consuming and prone to human error. Thus a subroutine, programmed in Tcl-language, has been developed to be run within Altair HyperWorks with the aim of providing the user with an auxiliary tool which automates the application of the ply elimination loop to the finite element model of a composite laminate. An overview is also presented for future developments and extensions to the present subroutine.

The Author

Daniele Di Sanzo
Stress Analysis Engineer at Rotor Systems Design & Development Department
AgustaWestland