Building block approach is a rational multi-level analysis and testing development approach used by many aerospace companies to certify metallic and composite structures.  Costly and time-consuming allowable programs hinder application of novel composite materials and often forces designers to use legacy materials that have establish material allowable databases.  In order to promote and accelerate the insertion of novel composite material systems into designs, efficient and reliable allowable/screening programs coupled with validated analytical models are required to reduce certification time and cost by ensuring material performance meet program goals.  This enables expansion of design variables to optimize structural performance and ability to streamline design changes reducing the product development cycle.   Current certification methodologies account variability in material properties through numerous tests and analysis/statistical procedures to ensure the safe operation of the aircraft throughout its design service goal under standard operating conditions.  An approach for producing stochastic simulations for material variability over the production cycle (using reduced-sample screening tests and information gathered from historical data for legacy materials) that mimic thousands of data points generated from testing various material batches and production cycles for generating virtual allowable is proposed.  The approach is validated through multi-scale modeling and statistical procedures for several legacy material systems.  This approach aims to provide multi-scale analysis examples and a means of generating an efficient test program for developing virtual allowables for specific levels of reliability (ex. A- or B-basis).  The validated analytical models can then be used to model more complex geometries and to reduce the burden of certification testing requirements.

Researchers should cite this work as follows:

• 2014 JEC Innovative Composites Summit, Boston

• Waruna Seneviratne; John Tomblin; Chee Chan; Tharindu Jayaratne (2014), "Accelerated Insertion of Advanced Materials for Aircraft Structures & Repair," https://cdmhub.org/resources/576.

  BibTex | EndNote

1. Composite Simulations
2. Virtual Allowables