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The authors are motivated to investigate an effective method for achieving the knowledge-driven design in order to address the efficiency drawback in common CAD applications. In this paper, a systematic method, to embed in-depth engineering knowledge and to realize smart design changes in an advanced feature-based design, is proposed. To proof the feasibility and the effectiveness of the proposed method, a process fuel and water supply system has been designed comprehensively in the conceptual design stage. The findings of this research work are presented with some critical discussions at the end of this paper. The authors believe that this approach is easy to be implemented and useful to improve the knowledge reusability and engineering design productivity.
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Feature-Based Approach for a Process Supply System Design
Y.-S. Ma*, Q. Hadi
Department of Mechanical Engineering
University of Alberta
Edmonton T6G 2G8, Canada
Tel: (+1)780.492.4443
AbstractThe authors are motivated to investigate an
effective method for achieving the knowledge-driven design in
order to address the efficiency drawback in common CAD
applications. In this paper, a systematic method, to embed in-
depth engineering knowledge and to realize smart design
changes in an advanced feature-based design, is proposed. To
proof the feasibility and the effectiveness of the proposed
method, a process fuel and water supply system has been
designed comprehensively in the conceptual design stage. The
findings of this research work are presented with some critical
discussions at the end of this paper. The authors believe that
this approach is easy to be implemented and useful to improve
the knowledge reusability and engineering design productivity.
Keywordscomputer-aided design; knowledge modeling;
unified feature-based design; pressure vessel; parametric
Computer-aided design (CAD) tools have been widely
used in engineering; but the problem that how effectively
the modern CAD tools are used to deal with the challenges
of engineering complexity and knowledge embedment has
been puzzling many companies. A company’s engineering
department very often finds that it is repeating some similar
design modeling effort and yet the engineering models are
not able to be reused. Although there had been temptations
for using a previous project design for a new one, but the
integrity of engineering model becomes unknown to too
tedious to check. Such concerns are particularly strong in
the system conceptual design stage. Hence, a systematic
feature based method, to embed in-depth engineering
knowledge and to realize smart design changes in an
advanced feature-based design, is proposed.
To proof the effectiveness of the proposed method, a
convincing case study is necessary. Via an in-depth project,
a pilot but useful software system has been developed to
create an efficient and reusable oil and water supply design
so that industrial contractors can enhance their practices by
adopting the proposed approach. The reason to study such a
system to proof the concept is due to the ever increasing
demand for electricity across the globe that has lead to a
rapid rise in power plant construction and expansion. The
fuel and water system design in power plants is essential in
engineering design as it has major technical, operational,
and economic impacts. Piping layout and equipment design
is constantly changing with the advancement in the design,
manufacturing, installation and construction of the plant due
to various unseen factors. Hence it becomes important that
the design details are updated in a mechanical model
according to the changes in process and instrumentation
diagrams (PIDs) or the layout design with minimum efforts.
This is where advanced feature-based design modeling can
play an effective and important role. Although the majority
of power plants which are being set up are either based on
coal or natural gas technology, a diesel fuel power plant is
studied due to its suitable engineering scale and the
limitation of the research resources. The authors believe that
the proven method can be equally applied to larger scale
This paper highlights the advanced design features that
have been identified via a real world research project,
illustrates the representation of them in a future feature
modeling and development effort, and demonstrates the
design feature implementation mechanisms based on
parametric modeling. The advantages and drawbacks of this
proposed feature-based method is discussed.
Traditionally, the feature concept was used for
manufacturing. For example, machining features are
traditionally defined as volumes of material removed in
machining operations [1]. However, since features can
represent engineering semantic patterns effectively, hence,
there have been many researchers proposing the expansion
of the concept and the related modeling schemes such that
feature-based knowledge representation and implementation
methods can be more coherently and consistently developed.
A thorough review related to new feature types and their
research state of art has been available in [2]. One attempt
was to make various types of features to be more unified
under a common scheme such that associative nature of
advanced features [3] [4], such as cooling channels in
plastic injection mould, can be modeled and supported for
productivity enhancement software tools with certain
information management automation [5]. Such evolvement
of feature definition has made advanced feature application
broaden and more convenient.
To design a process supply system with the advanced
feature-based approach, there has been some challenges.
First of all, the definitions of features in such design
projects are non-standard and have never been explicitly
identified. For example, the piping layout in a diesel fuel
supply sub-system could be similar to the definition of
cooling channels in mould design [5]. Such features related
to conceptual design are even more difficult because of the
2010 International Conference on Manufacturing Automation
978-0-7695-4293-5/10 $26.00 © 2010 IEEE
DOI 10.1109/ICMA.2010.11
2010 International Conference on Manufacturing Automation
978-0-7695-4293-5/10 $26.00 © 2010 IEEE
DOI 10.1109/ICMA.2010.11
2010 International Conference on Manufacturing Automation
978-0-7695-4293-5/10 $26.00 © 2010 IEEE
DOI 10.1109/ICMA.2010.30
2010 International Conference on Manufacturing Automation
978-0-7695-4293-5/10 $26.00 © 2010 IEEE
DOI 10.1109/ICMA.2010.30
abstract nature and further detailing in the down-stream [6]
[7]. Second, the design cycle involves multiple processes
including flow analysis, pressure vessel design and
geometry design simulation. Design changes occur
repetitively throughout the design cycles. The effective
mechanisms to implement, validate and consistently achieve
the downstream updates of changes are essential for
knowledge driven design approach [2] [8]. Hence, in-depth
case studies to identify, verify and prototype advanced
features are imperative to beef up the support for the
unification and diversification of feature-based knowledge
engineering approach.
Parametric modeling, as an enabling mechanism for
knowledge base engineering modeling, is one of the new
and smart modeling techniques being employed in
industries. Parametric modeling can be understood as a
CAD modeling method which supports expressions in the
CAD environment and enables design model dimensions
used to be changed by changing the expression values.
Parametric modeling is the supporting mechanism for
feature-based design (references) approach. Parametric
techniques depend on well defined mathematical relations in
such a way that if one entity or parameter is altered, its
impacts on all the other relative parameters can be updated
automatically. A well-defined parametric modeling
application can embed design knowledge into the design
models in a generic manner, and significantly increases the
productivity of design processes. The main advantage of
parametric modeling is that there is no need for the
generation of new models based on the changes of input
design parameters, which eventually leads to the savings of
time, effort and cost. However, without an appropriate
design scheme, simply using parametric modeling creates a
lot of CAD modeling parameters such that their semantic
meanings, relations, and rules applied to them are tedious to
manage and engineers will be overwhelmed by the “hidden”
relations among parameters and dimensions if the design
task becomes reasonably complex, or if the engineer is not
or no longer familiar to the hidden parameters and their
embedded constraints.
In order to make better use of the parametric design
mechanism such that, many engineers, who in these days are
dependent on CAD tools to deliver their design contents,
can easily operate the design steps with their common
engineering semantic patterns and their design intent can be
fully defined and managed throughout iterative design
cycles of revisions, feature technology is required. A feature
defines relations between different entities in a semantically
explicit and coherent manner. A review on the development
of feature technology and the new paradigm of concurrent
and collaborative engineering has been available [2]. Via
features, design entities are calculated based on complex
relationships and mathematical formulas according to
typical engineering design patterns. Advanced feature-based
approach basically entails flexible well-defined feature
definitions, constraint management and effective service
functions, where, usually, object-oriented software
engineering methodology is used. In the reported research
project, a unified feature concept is applied when initiating
the engineering activities.
Figure 1. Semantic definition of unified feature in UML format [9].
Figure 2. System design for the proposed method.
The definition of a unified feature has been given in [9]
and shown in Figure 1. Basically, the design intent can be
expressed as a set of common, flexible, and well-defined
data structures, i.e. unified features, where the engineering
conceptual patterns, e.g. the pipeline layout, a piece of
equipment, or a key design code to be checked in the
context of a process supply system, are represented
generically in a set of geometric or topologic entities,
associated driving parameters, constraints, and attributes.
Unified features can be used to define the engineering
patterns at different semantic detail levels, and a set of lower
level unified-features can be used to define a higher level
feature. UML (Unified Modeling Language) representation
is standardized software modeling design method for
CAD Modules
Excel Modules
3D layout
Process design
CAE 3D mesh
Design code
User interface
code related
illustrating class property data and process definitions and
their relations in object-oriented programming methodology
This work is not about the coding aspect to achieve
unified feature modeling via software. Rather, it is a
verification and application of the proposed concept of
unified feature through a real example. The research tries to
answer two questions. The first is how unified feature
properties can be corresponding to a real application, and
the second is if the definition of the unified feature can be
generic enough for those similar projects so that the
engineering approach with it can serve as an effective
engineering information management method.
From application point of view, the project was also
aimed to create an efficient and reusable supply system
design models for some common industrial applications,
such as a power plant, by developing a feature-based CAD
parametric design model. Typically, there are three sub-
systems are considered for a power plant supply system, i.e.
diesel fuel, portable water, and fire water. Figure 2 shows
the system design of the proposed method.
V. E
In this work, to begin with, a process engineer (a user)
needs to interactively input the basic process parameters and
select the common process elements via an user interface of
Excel software template. Figure 3 shows a partial screen
snap of the input page.
Figure 3. Partial input page implemented with Excel.
Then, the detailed attributes to generate a 2D a process
and instrument diagrams (PID) for each sub-system is then
automatically created in a page. Based on his input, the 2D
PID diagram is parametrically generated in the CAD
system. Figure 4 shows the PID for the fire water supply
sub-system. Similarly, the PIDs for portable water and fire
water systems are also created parametrically. Such PIDs
are in fact a form of conceptual process design features.
They have to be validated by basic process calculation
formulas which are in turn a set of constraints to be satisfied
in the implementation of a feature-based system in the
Next, those attributes of the newly-created PIDs is used
as the design inputs and the piping layout and pressure
vessel designs attributes were created semi-automatically
via necessary interactions between the user (now, it could be
a mechanical designer) and the template pages of the
modeling system.
Figure 4. PID diagram for the fire water supply sub-system.
Figure 5. Fully generated conceptual 3D design in the CAD system.
Note that professional code regulations have been fully
considered at this stage by validate the design inputs via a
set of built-in code checking templates specially tailored
according to design rules. In this case, regulation codes,
such as ASME pressure vessel design codes under Section
VIII, have been implemented. Such codes can be understood
as design constraints and they have to be satisfied for the
detailed design parameters in order to validate the pressure
vessel conceptual design feature. Analytical calculation was
implemented in the Excel model.
Following the above design attribute generation step,
Autodesk Inventor was used for the development of the 3D
models and the driving parameters are controlled by Excel
spread sheet templates. Figure 5 shows a fully generated
conceptual design for the system. Figure 6 and 7 show the
fire water supply system model in more detail. Because of
the built-in software integration capability, this system
design (see Figure 2) supports that any changes can be
implemented into the 3D mechanical models with minimum
efforts via parametric modeling. Internal relations for each
design block, such a pressure vessel design dimensions, are
implemented into related formulas of Excel.
Figure 6. Fire water storage tanks and piping layout.
Figure 7. A closer view of the fire water supply sub-system.
Finally, all the analytical calculation done was further
validated with 3D finite element models which are created
based on the mesh output generated from the
aforementioned parametric CAD modeling step and
structural analysis was then carried out. Figure 8 shows the
stress analysis results for the diesel fuel storage tank with
the consideration of the saddles’ effect.
Design codes involved are modeled as a set of
constraints. The three sub systems are essential for the
operation of a power plant. Other than the diesel fuel sub-
system that is obviously necessary to provide constant
energy whereas the portable water and fire water system is
meant to supply water to the boiler, generator and the
incinerator plant building respectively. In the incineration
plant building the solid waste and liquid organic wastes are
treated. In all the systems, centrifugal pumps are used to
maintain the required pressure of systems. In the fire water
system jockey pump is also used so that if the pressure
drops due to any sort of leakage, or in emergency the
pressure will keep on dropping.
Figure 8. Maximum and minimum Von Mises stress values.
In order to maintain the required discharge pressure the
jockey pump will come into play. Jockey pumps are
attached in such a way that they come into act when drastic
pressure drop takes place. Once the pressure reaches up to
the minimum required pressure it is automatically switched
The main design codes and standards implemented are:
x ASME Section VIII, Division 1 - Boiler & Pressure
Vessel Design Code.
x API 650 Storage Tank Design.
x ASME B 31.1 - Power Piping Code.
x ASME B 16.10 Face to Face dimensions of Valves.
x ASME B 16.34 Valves Flanged, Threaded and
Welding End.
x ASME B 16.9 Butt Welded Fittings.
x ASME B 16.5 Pipe Flange and Flange Fittings.
x ASME B 36.10 Welded and Seamless Wrought
Steel Pipe.
In the Excel calculation, modular approach is used. For
the project, in additional to the major pressure vessel design
code checking module, the following modules are
implemented as well: flow calculation, pressure loss
calculations, pipe wall thickness calculation, fire water tank,
nozzle reinforcement calculation, dike wall calculation, area
reinforcement, and stress verification for saddles. It was
found that it was quite convenient to cluster calculations
according to the rules corresponding to the relater regulation
sources and their calculation sections. In such a way, code
verification and validation are made easier to be conducted
either automatically or manually by the designers.
Figure 9 shows a partial code checking template in Excel
for the pressure vessel design. Figure 10 shows the partial
implementation of constraints used for saddle design stress
To automatically interface with the CAD models created
in the CAD software, a dedicated page of model-related
attributes, corresponding to those driving CAD model
parameters, is developed as shown in Figure 11. The
interface page is constructed according to the parametric
modeling requirement of Autodesk Inventor form so that the
integration between Excel and Inventor can be fully
supported and parametric modeling is then readily achieved.
Figure 9. Constraints implemented for pressure vessel design module.
One advantage for feature-based modeling is the
parametric change management. Instead of changing
individual parameters, a set of them are change at a time. By
managing changes in groups, the consistency can be well
kept than updating parameters one-by-one because there
could be a lot of intermediate updating conflicts arise from
the in compatible values of a feature pattern.
Table 1 shows a set of parameters with the current and
new values to be assigned. Figures 12(a) and (b) shows
change effect on the horizontal water tank before and after
the change update. For the pressure vessel shown in Figure
12(a) there is only one rib in the middle of the support and
also there is no reinforcement pad shown, but for the
pressure vessel shown in Figure 12(b) there are two ribs and
also as per the nozzle reinforcement calculations the
reinforcement pad is updated automatically around the
nozzle connection.
Figure 10. Constraints implemented for the saddle of a horizontal storage
Figure 11. Partial list of attributes related to CAD model features.
This paper reports a new application case of the unified
feature definition [2] and supports the effectiveness of
applying advanced conceptual design features in real
industrial engineering, i.e. a process supply system
consisting of diesel fuel, portable water and fire water sub-
systems. Under the guiding principles of unified feature, the
implementation was carried out in a schematic manner but
mainly enabled by parametric modeling between CAD and
Excel interactions. Although the software coding has not
been done due to the resources constraint, however, it has
been clear that the unified feature definition has been useful
for the identification and organization of engineering design
patterns in this traditional but well regulated application
domain. More research on the development of a reusable
design software toolkit is expected as the future work.
This research effort was partially supported by a Canada
NSERC Discovery grant (No. 355454-09) and the University
of Alberta.
Internal pressure of vessel (bar)
Height of the vessel from ground level (ft)
Outside diameter of the vessel shell (inches)
Distance between horizontal vessel (m)
Net capacity of the vessel (m
) 100
Saddle dimensions a (inches)
B (inches)
C (inches)
D (inches)
E (inches)
No of ribs (ul)
G (base) (inches)
H (web flange ribs) (inches)
K (wear) (inches)
Fire water tank height of each course (m)
Diameter of the tank (m)
Pressure vessel nozzle nominal wall thickness
of nozzle (inches)
Exterior projection (inches)
Interior projection (inches)
Fillet size (inches)
Pressure Vessel model using original parameter values
(b) Pressure Vessel model using new parameter values
Figure 12. Partial list of attributes related to CAD model features.
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With widely used concurrent and collaborative engineering technologies, the validity and consistency of product information become important. In order to establish the state of the art, this paper reviews emerging concurrent and collaborative engineering approaches and emphasizes on the integration of different application systems across product life cycle management (PLM) stages. It is revealed that checking product information validity is difficult for the current computer-aided systems because engineering intent is at best partially represented in product models. It is also not easy tomaintain the consistency among related product models because information associations are not established. The purpose of this review is to identify and analyze research issues with respect to information integration and sharing for future concurrent and collaborative engineering. A new paradigm of research from the angle of feature unification and association for product modeling and manufacturing is subsequently proposed.
To allow a designer to focus on the information that is relevant for a particular product development phase, is an important aspect of integral product development. Unlike current modelling systems, multiple-view feature modelling can adequately support this, by providing an own view on a product for each phase. Each view contains a feature model of the product specific for the corresponding phase. An approach to multiple-view feature modelling is presented that supports conceptual design, assembly design, part detail design and part manufacturing planning. It does not only provide views with form features to model single parts, as previous approaches to multiple-view feature modelling did, but also a view with conceptual features, to model the product configuration with functional components and interfaces between these components, and a view with assembly features, to model the connections between components. The general concept of this multiple-view feature modelling approach, the functionality of the four views, and the way the views are kept consistent, are described.
This paper describes a new approach for generation, representation and selection of assembly sequence alternatives. In the presented methodology, geometric and mobility constraints extracted directly from the CAD model of the assembly are translated into two types of uni-directional matrices, which are called the contact and the translational functions. An algorithmic procedure is used to generate all feasible assembly sequences from these two functions. The sequences are then represented as a table of assembly states and assembly tasks in a hierarchical fashion starting from individual components in unassembled state to finished assembly. This assembly sequence table (AST) is also provided with editing features to apply strategic constraints in order to analyze all feasible sequences and determine the final sequence choice. An example has been provided to demonstrate the proposed approach.
This paper presents a case-based approach for reusing previous design concepts in conceptual synthesis of mechanisms. Design tasks for function generation and motion transmission are addressed in the current study. The basic idea of the present approach is to provide a computational framework for design synthesis by imitating the common design method of reviewing past designs to obtain solution concepts for a new design problem. A notion of virtual function generators is introduced to conceptualize and represent underlying design concepts contained in existing mechanisms. Virtual function generators are derived from previous designs, and serve as new conceptual building blocks for conceptual synthesis of mechanisms. Feasible design alternatives are generated by combining virtual function generators using some adaptation rules. The reuse of prior design concepts is accomplished via virtual function generators within the framework of case-based reasoning. The approach is demonstrated through an application.
Abstract Joints in product design are common because of the limitations of component geometric configurations and material properties, and the requirements of inspection, accessibility, repair, and portability. Collaborative product design is emerging as a viable alternative to the traditional design process. The collaborative assembly,design (AsD) methodologies,are needed for distributed product development. Existing AsD methodologies,have limitations in capturing the non-geometric aspects of designer’s intent on joining and are not efficient for a collaborative design environment. This paper introduces an AsD formalism and associated AsD tools to capture joining relations and spatial relationship implications. This AsD formalism allows the joining relations to be modeled symbolically for computer interpretation, and the model can be used for inferring mathematical,and physical implications. An AsD model generated from the AsD formalism,is used to exchange,AsD information,transparently in a collaborative AsD environment. An assembly,relation model,and a generic assembly relationship diagram are to capture assembly and joining information concisely and persistently. As a demonstration, the developed AsD formalism and AsD tools are applied on a connector assembly,with arc weld and rivet joints. q 2003 Elsevier Ltd. All rights reserved. Keywords: Assembly design; Design formalism; Service-oriented architecture; e-Design and realization; Collaborative assembly design; Joining process;
The promise of features technology was that the task domains would have access to task specific product data through feature based models. This is an important requirement in a distributed and concurrent design environment, where data of part geometry has to be shared between different task domains.Associativity between feature models implies the automatic updating of different feature models of a part after changes are made in one of its feature models. The proposed algorithm takes multiple feature models of a part as input and modifies other feature models to reflect the changes made to a feature in a feature model. The proposed algorithm updates feature volumes in other feature models and then classifies the updated volumes to obtain the updated feature model. The spatial arrangement of feature faces and adjacency relationship between features are used to isolate features in a view that are affected by the modification. Feature volumes are updated based on the classification of the feature volume of the modified feature with respect to feature volumes of the model being updated. The algorithm is capable of handling all types of feature modifications namely, feature deletion, feature creation, and changes to feature location and parameters. In contrast to current art in automatic updating of feature models, the proposed algorithm does not use an intermediate representation, does not re-interpret the feature model from a low level representation and handles interacting features. The present work considers modifications to form features only. Modification of constraints and application attributes are under investigation. Results of implementation on typical cases are presented.
Industrial Automation Systems and Integration -Product Data Representation and Exchange -Part 224: Application Protocol: Mechanical Product Definition For Process Planning Using Machining Features
International Organization for Standardization (ISO), Industrial Automation Systems and Integration -Product Data Representation and Exchange -Part 224: Application Protocol: Mechanical Product Definition For Process Planning Using Machining Features, ISO 10303-224:1999, ISO: Geneva, Switzerland,1999.