Research Activities: 2011

Advanced Moisture Modeling of Polymer Composites 
Status  Complete                          View Final Report: PDF
Sequential Number R296
Identification Number 00034385 
Matching Research Agency Bell Helicopter
Principal Investigator

K. Chandrashekhara
Curators’ Professor
Missouri University of Science and Technology
188 Toomey Hall
Rolla, MO, 65409

Student Involvement One Student
Project Objective Development of three-dimensional moisture model for polymer composites
Project Abstract With increasing usage of composite materials, study of the performance of composites exposed to different environments is of great interest. Over time, composite materials absorb moisture from the surrounding environment and this increase in moisture affects the structural integrity of the part. To ensure the structural integrity, determination of moisture concentration inside the composite structure as a function of time and position is important. Test methods have to simulate typical worst-case aircraft service water vapor environment: 80°F / 82% relative humidity (RH) for 10 years. Currently, accelerated diffusion procedures with 160°F / 95% RH environment are used to reduce the time period of the testing. Conducting the experiments in maintained test environments for elongated period of 10 years is a tedious process. Evaluation of moisture behavior of composites through simulation studies would be time and cost saving. Missouri S&T project with Bell Helicopter will have two tasks. In Task 1, commercial finite element codes will be used to simulate the 3-D model of a homogeneous (one type of material) composite and generate the hygroscopic effect (T/RH profile). In Task 2, hybrid material configurations are considered and interface resistivity is taken into account. In both the tasks, the moisture distribution through the thickness of the composite will be evaluated.
Anticipated Benefits To ensure structural integrity of polymer composites under moisture environment

Start Date: Feburary 18, 2012

End Date: August 31, 2013

Relationship to other Research/Projects Previous studies were on hydrogen storage cylinders and biocomposites
Technology Transfer Activities We are collaborating with Bell Helicopter to develop moisture models for composites.  These models  can be used for FRP composites  in infrastructure applications
Transportation Research Board Keywords Polymer composites, FRP, Moisture model, 3D simulation