The process of developing more efficient methods and tools for product
development is a never-ending process. One area where Volvo Aero
investigates how to increase efficiency in product development is by using
Knowledge Based Engineering (KBE) tools. KBE is a methodology to capture
product- and critical process knowledge by incorporating it into a
computerised environment. The main objective of this thesis is to answer
these questions given by Volvo Aero Corporation:
- How can the concept alternatives be described in a generative model?
- How should the product structure on such a model look like?
- How does it handle the concept variations that are requested?
The aim is to investigate the capabilities of Knowledge Fusion (KF) as a
conceptual design and evaluation tool for jet engine components. This is
done by implement a first stable core model into KF. The KBE-model is
representing a two-shafted Intermediate case (IMC). To verify the KBE-model
an existing engine model serves as a reference configuration.
To answer the questions above the work begins with gathering information and
knowledge about the IMC from design engineers and different documentations.
This knowledge is then incorporated into a generative product model inside
Knowledge Fusion. Parameters, objects and rules are explained and defined at
the same place, this way is a living document created. This way it will not
be a documentation saying one thing and a product model that is doing
something else.
General classes have been defined that can be repeatedly used to define the
concept alternatives. This results in a more efficient code and saves time
when defining new application. The product structure is built up with a
project definition at root level and different design cases as sub-objects
to this project object. Every design case has its own geometry, cost
evaluation, manufacturing process planning and analysis part that makes it
easy to evaluate and compare each design.
To allow many concept variations and form complex geometry such as struts
and airfoil rings, splines are swept to shape the surfaces. It is possible
to calculate the weight and a simple cost based on the geometry volume
defined by a surface model. The results from each Design Case are presented
in an html browser and are saved as a text file. A first step toward
manufacturing process planning is prepared by implement necessary root
objects in the product structure.
The wish is to have a functional driven method to define the product model
and this work is merely a first step toward this vision. The functionality
of the IMC is investigated and broken down and all classes defining the IMC
geometry have a functional description written in the header.
It is shown that KF is a program where it is possible to model complex parts
such as an IMC. Currently generative modelling is limited to geometry
modelling within a CAD part. Large benefits can be seen as generative
modelling is applied to a wider range of product modelling such as
engineering analysis integration and multi part assembly modelling. Since
this is one of the first commercial applications combining KBE with feature
based CAD systems the full potential is still to be defined.