Process Simulation Models and Noninvasive In-Situ Material State Monitoring for Detection of Process-Induced Damages in Polymer Composites
Abstract
Composite material cure recipes are based on manufacturer-recommended cure cycle inputs,which are developed as a result of various stochastic cure kinetics models during the developmentof resin formulation. The time, temperature, pressure, and vacuum integrity are inputs forautoclave cure, but none of them are direct measurements of the material state and have no directcorrelation to viscoelastic characteristics or mechanical performance of the cured material. Theproposed process development system includes autoclave controls that are modified so that the setpoints are controlled based on externally determined material state of the laminate in the autoclave,which is monitored remotely by a rheological measurements and a material state estimate basedon the process and cure state models. With the proposed process-control architecture, materialwill be cured to achieve the desired viscoelastic and mechanical properties with minimizing thevariability cause by the initial material state (ex., shelf- and out-life) by monitoring the rheologicalresponse and managing the autoclave temperature to achieve the desired cure state. It also directlymeasures the initial viscoelastic state, which is a measure of material performance at the point ofproduction rather than arbitrarily constraining the process solely to a time-temperature history, inorder to achieve an assumed cure state. The methodology will be used for interrogating themanufacturing-induced defects of polymer composites in a controlled environment and link themto boundary conditions. The material-state database developed through validated process modelsbrings about the virtual environment, where the actual boundary conditions can be interrogatedduring the cure, to ensure that the material achieves its optimal performance.Principal investigators are collaborating with Technical Data Analysis, Inc. and MissouriUniversity of Science and Technology for Navy STTR FY2015.A Topic N15A-0003; all threeaspects of this proposed research (rheological studies for an in-depth understanding formanufacturing defects formation, nondestructive inspections for developing repeated volumeelements for process analysis, and multi-scale multi-physics process modeling for predictingmanufacturing quality of composites) will enhance the activities planned for this STTR proposal.This research will provide an innovative virtual design tools for identifying process-induceddefects at early stages so that the composite design and manufacturing aspects can be optimized tominimize manufacturing defects. In addition, the proposed methodology provides a means ofmonitoring the rheological response rather than autoclave pressure-temperature history in order toachieve the desired viscoelastic and mechanical properties with minimal variability. The processmodels that will be developed as a part of this research will demonstrate the feasibility of theproposed approach for conducting a stochastic analysis of how process parameters effect therheological and mechanical performance of polymer composites.The three key aspects of this research provide an opportunity for university researchers andstudents to expand their knowledge of composite manufacturing, nondestructive inspection, andprocess modeling. The hands-on experience gained from these various fields will be beneficialfor future proposal development as well as for creating a pipeline of future engineers who areknowledgeable and experienced in various key aspects involving composite manufacturing.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2017
- Source ID
- N000141712066
Entities
People
- Waruna Seneviratne
Organizations
- Office of Naval Research
- United States Navy
- Wichita State University