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Systems Knowledge - A4

From CKN Knowledge in Practice Centre
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Welcome to the Systems Knowledge volume. This volume lays out and describes a science-based, systems level approach to tackle composite manufacturing problems. Just as in engineering design[1], all manufacturing processes can be broken down into components and sub-assemblies, which form the basis of a manufacturing system. In that way, a systems-level approach can be applied to manufacturing engineering. System's knowledge focuses, from a physics-based perspective, on the interaction between system components and how these interactions influence the system outputs. The framework for this method of thinking, as applied to composites manufacturing, was developed as part of the doctoral work of Dr. Janna Fabris[2] under the supervision of Dr. Anoush Poursartip.


The design and workflow of a manufacturing factory is a complicated problem, but one that is important for ensuring part quality. Approaching the factory from a systems level perspective allows for the problem to be deconvoluted. A factory can be broken into multiple cells where the different process steps of the factory take place, from receiving of raw materials through to shipping of the completed part. Raw material is brought into the cells, shaped on tooling, and passed through various equipment to create the part. The interaction between the material (M), shape (S), tooling and consumables (T), and equipment (E) for a given process (P) define the part quality. This is the basis of the MSTEP approach used throughout the KPC. The interactions between M, S, T, and E (known collectively as MSTE) can be categorized into themes such as thermal management (TM), material deposition management (MDM), flow and consolidation management (FCM), and residual stress and dimensional control management (RSDM).


This volume focuses on the interactions between material, shape, tooling, and equipment with respect to the part for each of the manufacturing themes. Refer to the Level I view to navigate to the Systems Knowledge content quickly. Refer to the Level II view to navigate the Systems Knowledge content with some direct links to important, detailed concepts. Refer to the Level III view to gain a more in-depth understanding of the systems-approach to composite manufacturing.


TM Icon-JJBnrDwmVS9r.svg
MDM Icon-JJBnrDwmVS9r.svg
FCM Icon-JJBnrDwmVS9r.svg
RSDM Icon-JJBnrDwmVS9r.svg
Thermal management
Material deposition management
Flow and consolidation management
Residual stress and dimensional control management
Read more

Thermal management is concerned with managing the thermochemical response of materials in storage/handling as well as the thermal response of parts during deposition and thermal transformation. A large focus is placed on the lattermost activity as this is the crux of thermal management. Click here to explore thermal management.

Material deposition management deals with the steps involved in placing material into the correct position on a tool or with combining fibre, resin, and other constituent materials on tools. Examples include robotic-placed prepreg tape on a tool and resin infusion of a fabric preform draped on a tool. Click here to explore material deposition management.

Flow and consolidation management is concerned with managing the changes in the physical response of parts/tools when the resin is predominantly in a liquid phase (eg. pre-gelation, pre-solidification) and the prevention of manufacturing defects such as wrinkling and porosity. Click here to explore flow and consolidation management.

Residual stress and dimensional control relates to the management of internal stresses that occur as the material undergoes differential thermal and phase change volume changes, and the matrix gains elastic memory due to viscoelastic property development. This includes controlling the changes in the mechanical response of parts and subsequent geometric changes when removed from tools or when parts are post cured. Click here to explore residual stress and dimensional control management.

How to use this volume[edit | edit source]

Volume framework[edit | edit source]

This volume lays out and describes a science-based, systems level approach to tackle composite manufacturing problems. This approach is at the core of the KPC framework and is utilized and expanded upon in proceeding volumes. When navigating this volume, users will be reintroduced to the notion of composite manufacturing as a systems problem. As users navigate to more advanced pages, Foundational Knowledge content and physics-based simulations are used to demonstrate and explain how system components influence composite manufacturing outcomes. The effect of individual components on the system are described in detail in these pages.

This volume focuses on the material, shape, tooling, and equipment interactions for various themes. It does not go into detail into how these interactions may influence different processes. In this regard, the volume isolates, and discusses in detail, the MSTE component of the MSTEP approach. To gain a complete understanding of the MSTEP approach refer to the systems approach to composite materials page. To learn more about the individual factory objects, process steps, and factory layout, visit the Systems Catalogue volume.

Volume features[edit | edit source]

Coming soon.

Content[edit | edit source]

Thermal management[edit | edit source]

TM Icon-JJBnrDwmVS9r.svg
Thermal management is concerned with managing the thermochemical response of materials in storage/handling as well as the thermal response of parts during deposition and thermal transformation. A large focus is placed on the lattermost activity as this is the crux of thermal management.


Learn more about thermal management:

Material deposition management[edit | edit source]

MDM Icon-JJBnrDwmVS9r.svg
Material deposition management deals with the steps involved in placing material into the correct position on a tool or with combining fibre, resin, and other constituent materials on tools. Examples include robotic-placed prepreg tape on a tool and resin infusion of a fabric preform draped on a tool.


Learn more about material deposition management (coming soon):

  • Effect of material
  • Effect of shape
  • Effect of tooling
  • Effect of equipment

Flow and consolidation management[edit | edit source]

FCM Icon-JJBnrDwmVS9r.svg
Flow and consolidation management is concerned with managing the changes in the physical response of parts/tools when the resin is predominantly in a liquid phase (eg. pre-gelation, pre-solidification) and the prevention of manufacturing defects such as wrinkling and porosity.


Learn more about flow and consolidation management (coming soon):

  • Effect of material
  • Effect of shape
  • Effect of tooling
  • Effect of equipment

Residual stress and dimensional control management[edit | edit source]

RSDM Icon-JJBnrDwmVS9r.svg
Residual stress and dimensional control relates to the management of internal stresses that occur as the material undergoes thermophysical-induced volume changes and viscoelastic property development occurs. This includes controlling the changes in the mechanical response of parts and subsequent geometric changes when removed from tools or when parts are post cured.


Learn more about residual stress and dimensional control management (coming soon):

  • Effect of material
  • Effect of shape
  • Effect of tooling
  • Effect of equipment

How to use this volume[edit | edit source]

Volume framework[edit | edit source]

This volume lays out and describes a science-based, systems level approach to tackle composite manufacturing problems. This approach is at the core of the KPC framework and is utilized and expanded upon in proceeding volumes. When navigating this volume, users will be reintroduced to the notion of composite manufacturing as a systems problem. As users navigate to more advanced pages, Foundational Knowledge content and physics-based simulations are used to demonstrate and explain how system components influence composite manufacturing outcomes. The effect of individual components on the system are described in detail in these pages.

This volume focuses on the material, shape, tooling, and equipment interactions for various themes. It does not go into detail into how these interactions may influence different processes. In this regard, the volume isolates, and discusses in detail, the MSTE component of the MSTEP approach. To gain a complete understanding of the MSTEP approach refer to the systems approach to composite materials page. To learn more about the individual factory objects, process steps, and factory layout, visit the Systems Catalogue volume.

Volume features[edit | edit source]

Coming soon.

System description[edit | edit source]

A factory is set of cells, each occupying a physical space, where one or more processing steps occur. In a composites manufacturing factory, there can be many different cells arranged in various ways depending on the part being produced. However, there are typically 14 general process steps that occur. They are as follows.

right
Systematic breakdown of a composites manufacturing factory

Generalized composite processing steps:

  1. Receiving
  2. Testing
  3. Storage
  4. Preparation
  5. Deposition
  6. Forming
  7. Thermal transformation
  8. Demoulding
  9. Trimming and machining
  10. Inspection
  11. Assembly
  12. Coating
  13. Reporting
  14. Packaging and shipping


Although most composite processing steps can be categorized according to the above list, the order in which these process steps occur is not fixed. Moreover, each generalized process step may comprise numerous specific steps depending on the material state and part being manufactured.

Each factory cell represents a sub-system within the entire factory. These sub-systems comprise the individual process steps occurring, which can be described and analyzed by the interactions between the materials (M), part shape (S), tooling & consumables (T) and equipment (E) within[2]. It is the equipment and tooling that act on the material to produce the part with a defined shape. The nature of these interactions can be categorized into different themes. That is, the set of governing equations, constitutive models, and material science that define the process interactions. With regards to processing of composite materials, there are four primary themes. They are thermal management (TM), material deposition management (MD), flow and consolidation management (FCM), and residual stress and dimensional control management (RDM). A given manufacturing process may incorporate multiple themes, however a discretized structure such as this may be used to systematically approach the problem.

In any system, there are parameters that one may wish to track in order to evaluate the system. These are known as outcomes and are representative of the outputs of the system. Evaluation of these outcomes are what define producibility. If the outcomes are acceptable, then the intended part quality at that stage of the manufacturing process has been achieved. In order for the finished part to achieve its intended quality, all outcomes from each factory cell must be acceptable. If the intended outcomes of an early cell are not achieved, knock-on effects may appear later on. Hence, why part/material quality should be checked at each stage of the manufacturing process. An example is the part temperature. An intended outcome of the system may be to have the part remain within a given temperature range over an alloted period of time during cure. If the condition is met, it's acceptable and therefore part producibility is satisfied; if not, it's unacceptable. Within each cell, the M, S, T, and E (MSTE) parameters are what define the state of that system. These parameters interact with one another to determine the system outcomes. Since outcomes are what define producibility, this becomes the crux of a systems-level problem - i.e. how does one tailor the system parameters for the applicable themes to achieve the desired outcomes?

Classes[edit | edit source]

Link to the Systems Catalogue page on factory objects

Interaction between MSTE classes

For each process step (P) there is always equipment (E) involved which acts on the part in someway. The part itself has a shape (S) and is comprised of a material system (M). Furthermore, the part is typically supported on tooling (T). Take hot press forming of a carbon-epoxy ski for example. The equipment is the hot press, the tooling is the mould that provides shape to the ski, the material is the specific carbon-epoxy blend (including its processing specifications), and the shape is the geometry of the ski with all of its intricacies.

The breakdown of a process step into the relevant material, shape, tooling, and equipment for a given processing theme is the backbone of the systems approach to composites manufacturing, as it allows for the problem to be setup and defined. Once the system is defined from the MSTE parameters, the physics-based interactions leading to the outcomes can be understood for each process step.

Material (M)[edit | edit source]

Link to material page within Systems Catalogue

The material represents the part material system and its processing specifications. For example, epoxy vs polyester resin and their processing requirements are material parameters. The interaction between the material and shape controls the outcome sensitivity of the system with respect to the part. For example, the material system and the part geometry define how the part will respond to an imposed temperature.

Shape (S)[edit | edit source]

Link to shape page within Systems Catalogue

The shape represents the geometry of the part. This includes thickness, surface area, volume, contours, and any geometrical features within the part (ply drops for example). Together, the shape and the material define the part.

Tooling and consumables (T)[edit | edit source]

Link to tooling and consumables page within Systems Catalogue

Tooling interfaces directly with the part, providing shape and imparting a boundary. Tooling may move between factory cells or be an asset of a single cell. For example, a part may be placed on a tool in the deposition cell and then transported to the thermal transformation cell where it is cured. Consumables are one-time-use objects that serve any number of purposes. A vacuum bag is an example of a consumable. The part is always bound by some form of tooling or consumable. Therefore, external stimuli (such as temperature) must move from the equipment, through the tooling, and into the part.

Representation of the MSTE classes within the factory
Equipment (E)[edit | edit source]

Link to equipment page within Systems Catalogue

Equipment are physical assets within a factory cell that provide external stimuli to the system. Their purpose is dependent on the stage of processing they are intended for. For example, a hot press is a piece of equipment that may be used to cure a composite, thermoform, or do both. In that regard, a hot press is a piece of equipment that may be used during thermal transformation and/or deposition. Together, the equipment and tooling represent the system boundary conditions with respect to the part.

Process step (P)[edit | edit source]

Link to factory process flow within Systems Catalogue

The process steps are the individual processes that occur throughout the factory. Each can be described by its MSTE components and their interactions. Each process step exists within one or more factory cells (physical spaces within the factory).

Factory (F)[edit | edit source]

Link to factory page within Systems Catalogue

The factory is the aggregation of all MSTE objects, all processing steps, and the factory cells. In other words, it is the collection of all items, actions, and physical spaces involved in manufacturing. An important stage in the factory flow is evaluating the outcomes after each process step in order to demonstrate producibility. Producibility refers to the acceptability of parts as they move through the factory, based on part quality. Quality is determined by the outcomes of the MSTE interactions for each process step (i.e. each MSTEP occurence).

Themes[edit | edit source]

The process steps that occur within each cell of a composites factory can generally be grouped under one of the four following themes.

Thermal management (TM)[edit | edit source]

Link to thermal management page

Thermal management is concerned with managing the thermochemical response of materials in storage/handling as well as the thermal response of parts/tools during deposition and thermal transformation. A large focus is placed on the lattermost activity as this is the crux of thermal management.

Material deposition management (MDM)[edit | edit source]

Link to material deposition management page

Material deposition management deals with the steps involved in placing material into the correct position on a tool or with combining fibre, resin, and other constituent materials on tools. Examples include robotic-placed prepreg tape on a tool and resin infusion of a fabric preform draped on a tool.

Flow and consolidation management (FCM)[edit | edit source]

Link to flow and consolidation management page

Flow and consolidation management is concerned with managing the changes in the physical response of parts/tools when the resin is predominantly in a liquid phase (eg. pre-gelation, pre-solidification) and the prevention of manufacturing defects such as wrinkling and porosity.

Residual stress and dimensional control management (RSDM)[edit | edit source]

Link to residual stress and dimensional control management page

Residual stress and dimensional control relates to the management of internal stresses that occur as the material undergoes thermochemical volume changes and viscoelastic property development occurs. This includes controlling the changes in the mechanical response of parts and subsequent geometric changes when removed from tools or when parts are post cured.

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References

  1. [Ref] Ashby, M.F. (2011). Materials Selection in Mechanical Design. Elsevier. doi:10.1016/c2009-0-25539-5. ISBN 9781856176637.CS1 maint: uses authors parameter (link) CS1 maint: date and year (link)
  2. 2.02.1 [Ref] Fabris, Janna Noemi (2018). A Framework for Formalizing Science Based Composites Manufacturing Practice (Thesis). The University of British Columbia, Vancouver. doi:10.14288/1.0372787.CS1 maint: uses authors parameter (link)


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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.