Web-Based Manufacturability Analysis
Main Participants: Satyandra
K. Gupta, Ramakrishna Arni, and Yusheng Chen
Sponsors: This project was sponsored by the National Science
Foundation and the National Institute for Standards and Technology. We
also received in-kind support from Galorath Inc. for this project.
Keywords: Manufacturability Analysis and Web-Based Services
Motivation
With the advent of high speed networking technology and recent advances
in information modeling area, we are entering into a new era of a
global
manufacturing economy connected through Internet. In tomorrow's
marketplace,
companies and individuals will be able to buy and sell manufacturing
services
on the Internet. The key technology to realize this vision will be a
brokering
technology that will provide match making services between
manufacturing
service providers and designers. Such services will register and manage
manufacturing
services---allowing designers to locate and access highly advanced
manufacturing
services. To ensure that the part being submitted is manufacturable,
the
brokering agency will need to provide manufacturability analysis
service.
Such a service will be used by designers to ensure that the proposed
design
can be manufactured by the selected process provider.
We need a framework for developing and deploying a variety of web-based
manufacturability analysis services. These services will range from a
service
for providing manufacturability advice during design embodiment to a
service
for evaluation of detailed designs against specific processes.
Main Results and Their Anticipated Impact
We have developed two web-based manufacturability analysis services in
this project.
A web-based manufacturability analysis service for solid freeform
fabrication. We have developed a manufacturability analysis system
that allows designers to analyze manufacturability of parts produced
using Solid Freeform Fabrication (SFF) processes with flatness
tolerance requirements on the part. SFF processes approximate objects
using layers; therefore the part being produced exhibits staircase
effect. The extent of this staircase effect depends on the angle
between the build orientation and the face normal. Our service
primarily serves
two different types of users --- process providers and designers.
Process
providers register their process's capabilities and constraints with
our
service. Designers upload the geometry and tolerance information to our
server
and select a process from the list of registered processes and perform
an
analysis of the feasibility of manufacturing the part using the
selected process.
Our service also offers suggestions for improving manufacturability of
difficult
to produce parts. We use a two-step approach to perform the
manufacturability
analysis. We first analyze each specified tolerance on the part and
identify
the set of feasible build directions that can be used to satisfy that
tolerance.
As a second step, we take the intersection of all sets of feasible
build
directions to identify the set of build directions that can
simultaneously
satisfy all specified tolerance requirements. If there is at least one
build
direction that can satisfy all tolerance requirements, then the part is
considered
manufacturable. Otherwise, the part is considered not manufacturable.
We
also have developed an algorithm to formulate redesign suggestions that
can
propose suitable modifications to the part design so that a
non-manufacturable
part can become manufacturable. Our research is expected to help (1)
designers
in eliminating manufacturing problems and selecting the right SFF
process,
and (2) process providers in selecting a build direction that can meet
all
design tolerance requirements.
A web-based process material advisory system. We have developed
a systematic approach to material and process selection during
embodiment design of mechanical components. We follow a three-step
approach to process and material
selection. We first generate combinations of materials and primary
processes.
Then, we find the set of non-dominated sequences for each combination
found
in the first step by adding secondary and tertiary processes to meet
detailed
form requirements and pruning dominated sequences. Finally, designers
can
use our cost analysis functions to compare different non-dominated
sequences to select the final combination of material and process
sequence. We have implemented our approach and algorithms in a
prototype web-based system called WiSeProM (Wizard for Selecting
Processes and Materials). Our system demonstrates the following:
- It shows that it is possible to accounts for imprecision in
design parameters in selecting material and processes. The
effectiveness of our algorithm
depends on how tightly various parameters can be defined during the
embodiment
design stage. If parameters have very large ranges, then very few
solutions
dominate other solutions and the pruning conditions do not work very
effectively.
If parameters have reasonably small ranges, then pruning conditions
work
effectively.
- It shows how to automatically generate process sequences to
satisfy the form requirements when a single process cannot meet all the
form requirements. Unlike previous approaches, there is no restriction
on the number of processes used in a sequence. Therefore, it allows us
to solve problems that require four or more processes.
- It shows how to construct an open architecture system in which
databases and algorithms are completely separated. Therefore, as soon
as new material and/or process information is added to the database, it
can be immediately used in our system.
We believe that our system will allow designers to explore a large
number of material and process options during the embodiment design
stage and to select the most cost-effective combination. By selecting
the material and process combination during the early design stages,
designers can ensure that
the detailed design is compatible with all of the process constraints
for
the selected processes.
Related Publications
The following papers provide more details on the above-described
results.
- S.K. Gupta, Y. S. Chen, S. Feng, and R. Sriram. A system for
generating process and material selection advice during embodiment
design of mechanical components. Journal of Manufacturing Systems,
22(1):28--45, 2003.
- R.K. Arni and S.K. Gupta. Manufacturability analysis of flatness
tolerances in solid freeform fabrication. Journal of Mechanical
Design, 123(1):148--156, 2001.
- R.K. Arni, S.K. Gupta, and M. Kumar. A web based tolerance
analysis
service for solid freeform fabrication. In ASME’s Design for
Manufacturing
Conference, Baltimore, Maryland, September 2000.
- S. Rajagopalan, J. M. Pinilla, P. Losleben, Q. Tian, and S.K.
Gupta.
Integrated design and manufacturing over the Internet. In ASME’s
Computers
in Engineering Conference, Atlanta, GA, September 1998.
Some of these papers are available at the publications
section of the website.
Contact
For additional information and to obtain copies of the above papers
please contact:
Dr. Satyandra K. Gupta
Department of Mechanical Engineering and Institute for Systems Research
2135 Martin Hall
University of Maryland
College Park, Md-20742
Phone: 301-405-5306
FAX: 301-314-9477
WWW: http://www.glue.umd.edu/~skgupta/