The CKN Knowledge in Practice Centre is in the early stages of content creation and currently focuses on the theme of thermal management.
We appreciate any feedback or content suggestions/requests using the links below

Content requests General feedback Feedback on this page

Reference - Thermal Modeling Validation Techniques for Thermoset Polymer Matrix Composites

From CKN Knowledge in Practice Centre
Type Thesis
Title Thermal Modeling Validation Techniques for Thermoset Polymer Matrix Composites
Abstract Process modeling is becoming a widely-accepted tool to reduce the time, cost, and risk in producing increasingly large and complicated composite structures. Process modeling reduces the need for physical parts, as it is not practical or economical to design and fabricate large composite structures using a trial-and-error approach. The foundation of the composite manufacturing process, and thus of process models, is the thermal history of the composite part during cure. Improperly curing the composite part will compromise its mechanical properties. Consequently, proper validation of the thermal model input parameters is critical, since the simulation output depends on the accuracy of the input. However, there are no standard methods to validate thermal process model input parameters. In this work, repeatable and robust methods were developed to isolate and validate the conductive heat transfer, thermochemical, and convective heat transfer sub-models. By validating the sub-models, the uncertainty of the complete thermal simulation was significantly reduced. Conductive and thermochemical material models were validated by comparing the thermal response of a material surrounded by rubber bricks to a 1-D simulation of the same materials. Four composite prepreg systems and their respective material models were tested, with agreement ranging from excellent (errors less than 1.0 °C) to poor (errors greater than 5.0 °C). Calorimetery, visual monitoring, and CFD were used to characterize the convective heat transfer environment inside the UBC autoclave. The validation methods were also used to better understand the capabilities and limitations of the autoclave. Local variations in airflow patterns and heat transfer coefficients showed that heat transfer can be highly variable in an individual piece of equipment. Simple procedures for characterization of an autoclave or oven were demonstrated. The developed methods can be used individually, or in combination, to validate thermal models and reduce uncertainties associated with the cure of composites. With further refinement, the demonstrated methods can be developed into validation standards for thermal modeling of composite materials.
Authors
  • Slesinger, Nathan Avery
City Vancouver
Department Materials Engineering
Date 2010
University The University of British Columbia, Vancouver
Publication UBC Open Collections
Websites
DOI 10.14288/1.0071063
Country Canada
Cite
To cite this Reference:
  1. Edit any page with the VisualEditor.
  2. Position the cursor where the citation is needed.
  3. On the VE toolbar, click "Insert", then "Template".
  4. In the dialog form field, enter "Ref".
  5. Click "Add template".
  6. In the "Reference Page name" field, enter "2b0c4d3e-23c8-3d1f-9251-c21bd5560fdb".
  7. (optional) Add a page number or range by clicking "Add more information".
  8. Click "Insert".
CKN KPC logo

Welcome

Welcome to the CKN Knowledge in Practice Centre (KPC). The KPC is a resource for learning and applying scientific knowledge to the practice of composites manufacturing. As you navigate around the KPC, refer back to the information on this right-hand pane as a resource for understanding the intricacies of composites processing and why the KPC is laid out in the way that it is. The following video explains the KPC approach:

Understanding Composites Processing

The Knowledge in Practice Centre (KPC) is centered around a structured method of thinking about composite material manufacturing. From the top down, the heirarchy consists of:

The way that the material, shape, tooling & consumables and equipment (abbreviated as MSTE) interact with each other during a process step is critical to the outcome of the manufacturing step, and ultimately critical to the quality of the finished part. The interactions between MSTE during a process step can be numerous and complex, but the Knowledge in Practice Centre aims to make you aware of these interactions, understand how one parameter affects another, and understand how to analyze the problem using a systems based approach. Using this approach, the factory can then be developed with a complete understanding and control of all interactions.

The relationship between material, shape, tooling & consumables and equipment during a process step


Interrelationship of Function, Shape, Material & Process

Design for manufacturing is critical to ensuring the producibility of a part. Trouble arises when it is considered too late or not at all in the design process. Conversely, process design (controlling the interactions between shape, material, tooling & consumables and equipment to achieve a desired outcome) must always consider the shape and material of the part. Ashby has developed and popularized the approach linking design (function) to the choice of material and shape, which influence the process selected and vice versa, as shown below:

The relationship between function, material, shape and process


Within the Knowledge in Practice Centre the same methodology is applied but the process is more fully defined by also explicitly calling out the equipment and tooling & consumables. Note that in common usage, a process which consists of many steps can be arbitrarily defined by just one step, e.g. "spray-up". Though convenient, this can be misleading.

The relationship between function, material, shape and process consisting of Equipment and Tooling and consumables


Workflows

The KPC's Practice and Case Study volumes consist of three types of workflows:

  • Development - Analyzing the interactions between MSTE in the process steps to make decisions on processing parameters and understanding how the process steps and factory cells fit within the factory.
  • Troubleshooting - Guiding you to possible causes of processing issues affecting either cost, rate or quality and directing you to the most appropriate development workflow to improve the process
  • Optimization - An expansion on the development workflows where a larger number of options are considered to achieve the best mixture of cost, rate & quality for your application.