Composite materials engineering webinar series - A119
The Composites Knowledge Network (CKN), in partnership with SAMPE Canada, hosted a 12-part webinar series on composite materials engineering from May through November 2020.
This series is intended for engineers, both junior and senior, who are looking to obtain a solid background in the fundamentals of composites to help make both engineering and business decisions. After completing this series, participants will have the skills to identity suitable applications for composites, select materials and processes, estimate composite mechanical properties, and identify appropriate testing procedures.
List of webinar episodes[edit | edit source]
The following table provides an outline of the webinar series and details on the topics covered in each webinar.
|Webinar number||Webinar title||Contents|
|1||Introduction||This first session is an introduction to what composite materials are. It gives an overview of common applications, and discusses challenges and success stories. The latter half of the session provides an overview of the remainder of webinar series.|
|2||Constituent Materials - Fiber||Composites are made up of two separate and distinct materials referred to as constituent materials. In this session we focus on commonly used fiber reinforcement materials such as carbon fiber, glass fiber and aramid (Kevlar) fiber. Examples of typical applications are presented along with information on selecting the right fiber for a specific application.|
|3||Constituent materials - Resin||Composites are made up of two separate and distinct materials referred to as constituent materials. In this session will focus on commonly used polymer matrix materials such as epoxy, polyester, and PEEK. Both thermoset and thermoplastic materials are discussed. Examples of typical applications are presented along with information on selecting the right resin for your application.|
|4||Thermal management and resin cure||Thermal management involves heat transfer into and out of the composite material during the curing/forming process. In this session we will look at factors affecting heat transfer, how to control them, and how to simulate the thermal management of a process.|
|5||Manufacturing processes - Introduction||This session provides an introduction and overview of common manufacturing processes. Examples of when and where these processes are applicable are given with an emphasis on how to select the right process for your application.|
|6||Manufacturing processes - Prepreg processing||Prepreg materials are composed of fiber and partially cured resin that is combined at a specific, tightly controlled ratio. It is the most common form of material used in aerospace. This session goes into more detail on prepreg materials and the processes used to manufacture parts with them.|
|7||Manufacturing processes - Liquid composite moulding||Liquid composite moulding is a family of processes that involve saturating dry fiber reinforcement with a resin using a pressure differential in the mould. Common processes include vacuum infusion (vacuum assisted resin transfer moulding (VARTM)), resin transfer moulding (RTM), and light resin transfer moulding (LRTM). This session describes the fundamental differences in the aforementioned processes, and when and where each process is applicable. We introduce resin flow theory based on Darcy’s law and a procedure for process design.|
|8||Mechanics of composites - Part 1: Lamina level||In this session we introduce the basics of calculating the mechanical properties of a composite material. We introduce and define a lamina, a single ply of composite material. Then we go into micromechanics, which is used to predict basic mechanical properties. With that groundwork set, we introduce Hooke’s law for orthotropic materials and describe how a lamina reacts to loading from different directions/fiber orientations.|
|9||Mechanics of composites - Part 2: Laminate level||In this session we build on what was introduced at the lamina level in the last session and build it up to a full laminate. We introduce laminated beams and plates, including laminate plate theory and the [ABD] matrix.|
|10||Failure of Composites||Building on Sessions 8 and 9, this session goes into both the analytical and practical aspects of failure. Stress analysis and failure theories are introduced. Failure modes are discussed and demonstrated with micro and macroscopic images of actual failure on a laminate level.|
|11||Defects||Defects in composite materials are a major concern. They typically occur during processing and often become the limiting factor of a part’s performance. In this session we introduce and classify various types of defects, then go into more detail on common defects such as thermal issues during cure, dimensional control, porosity, and fiber misalignment.|
|12||Testing||Given the wide variety of constituent materials, processing methods, and configurations, testing composites is critical. This session introduces the common methods of destructive and non-destructive testing and how to navigate through the myriad options.|
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 factory
- Factory cells and/or the factory layout
- Process steps (embodied in the factory process flow) consisting 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.
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:
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 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.