Aero-structure Cost Estimation
and Optimization Integrated KBE
System
PhD Candidate: Xiaojia Zhao
Department: C&O
Section: Air Transport & Operations
Supervisor: R. Curran
Promoter: M.J.L. Van Tooren
Start date: 10-15-2010
Funding: Chinese Scholarship Council (CSC)
Cooperations: TAPAS, Fokker
Background
Research Methodologies
This research focuses on thermoplastic aero-structure cost
estimations, relevant sensitivity analysis and optimization
studies. Thermoplastic components, as a new generation
of composite aero-structures, are specialized with their
low-cost, less maintenance properties. The cost model
based on component geometry and production process is
performed to verify this viewpoint. Along with the cost
estimation, in order to gain the insight between cost value
and its inputs, the sensitivity analysis is conducted to
illustrate the influence of the cost driving parameters.
Moreover, the design optimization involves cost
performance is critical to aerospace industry, therefore,
optimization studies based on sensitivity information are
being investigated. The overall application is built based
on a Knowledge Based Engineering (KBE) system, socalled Design and Engineering Engine (DEE), the cost
model, sensitivity analysis and optimization process are
embedded within DEE for the practical application
development.
•Integrating cost analysis into conceptual design
phase
The overall implementation couples the cost estimation
model within DEE (Fig.3). As a KBE system, which is able
to assist aero-structure conceptual design, the DEE allows
the cost engineer to capture formalized knowledge and
structured data from the design and manufacturing aspects.
The Capability Modules (CM) associated with Multi-Model
Generator (MMG) is developed for parameterized product
model and cost estimation pre-processing; cost, weight
and structural analyses are disciplinary performance
analysis tools which provide inputs for cost involved
optimization studies.
derived, the cost calculator takes each BOM item as the
input to performing calculations and exporting results. The
cost calculator is based on Cost Estimation Relationships
(CERs) involving shape, material and production factors as
cost causes. Fig. 4 shows an example of cost estimation
processes during stiffened-panel design. The design is
benefited from the cost estimation in terms of development
time and effort. In addition, it brings benefit to the general
performance of the aero-structures from a life cycle and
total value perspective.
• Developing sensitivity analysis and design
optimization considering aero-structure cost
As an essential step of optimization study, sensitivity
analysis is capable to provide gradient information as well
as the impact of the design parameters w.r.t. the design
performance. The implementation of cost sensitivity
analysis is under development. It will be based on target
function and constraints, using advanced and efficient
derivative computation to derive the sensitivity. Accordingly,
the optimization studies in terms of minimizing production
cost, Direct Operating Cost (DOC) are investigated.
Research Objective
Aerospace Engineering
In order to involve cost performance into conceptual
design phase, it aims at developing Thermoplastic aerostructure cost estimation, sensitivity analysis and design
optimization within KBE system.
Progress and Future Steps
According to the implementation, it shows KBE approach is
able to cope with the complexity of design rules and
parameterized product geometry. Design knowledge in
terms of product, process and cost is captured within the
KBE system. Those knowledge is also reflected on the
disciplinary views of the master geometry.
Initial cost result shows the cost of thermoplastic stiffenedpanel can benefit from cost-effective manufacturing
processes. More accurate results will be obtained according
to detailed data inputs and accurate CERs. At this stage,
this research has developed a detailed procedure to
estimate the cost in fast and modular paradigm, which
works as a tool enabling cost engineers to concentrate on
the final cost other than detailed cost estimating process.
Moreover, it enables designers to get an overview of the
product associated with shape, production and cost
properties.
Modularized sensitivity analysis will be developed to feed
the optimization work flow. Verified optimization results are
required to illustrate the capability of this application.
Fig.3 Adapted DEE for Aero-structure Cost Analysis
and Optimization Studies
Fig.1 TAPAS Project wing box productions
G650
Tail Structure
Horizontal tail
Rudder
•Developing cost estimation tool using geneticcausal technique and KBE technique
For cost estimation, an automated pre-processing is
performed in order to generate producible geometry and
the detailed data required by Product Breakdown Structure
(PBS) and Bill Of Materials (BOM). Once the BOM is
MMG
Manufacturing-sequence:
Part:
Stringer
PBS
Cutting, Hand lay-up, Consolidation, Pressforming
IF part type stringer
AND material T300/PPS
THEN manufacturing-sequence
Cutting, Hand lay-up, Consolidation, Pressforming
Fig.2 TAPAS Project and TUD-Fokker
Project Aero-structures
Assembly-method:
Resistance-welding
Assembly:
skin-stringer connection
IF connection type skin-stringer
connection
AND material1 T300/PPS
AND material2 T300/PPS
THEN assembly-method
Resistance-welding
Relevant Projects
•The TAPAS Project
Objective:
The Thermoplastic Affordable Primary Aircraft Structure
(TAPAS) project aims at the development of primary
structural parts and the research into corresponding
technologies. (Fig.1 & Fig.2)
Related research aspects:
Thermoplastic aero-structure production cost estimation;
Cost modelling integrated KBE system.
•Fokker-TUD project
Objective:
Improve the component design process by enabling cost
and weight sensitivity studies on the design proposal phase
for aircraft movables. (Fig.2)
Related research aspects:
Cost estimation pre-processing; Cost sensitivity analysis.
b)
a)
BOM
CERs Collection
Cost Calculation
Cost result
IF part type XX
THEN chipped-rate XX
IF production-sequence (XX XX)
THEN labor-hour
(XX XX)
…
Direct Operating Cost
Recurring cost
Labor cost
Material cost
…
Cost Data
Base
g)
f)
c)
e)
list
((:name xx
:ID xx
:part type xx
:material(s) xx
:additional-material xx
:production-sequence
(manufacturing-sequence or
assembly-method)
list(xx xx)
:length xx
:width xx :thickness xx)
…)
Fig.4 Example of Automated Cost Estimation Process for Aircraft Stiffened-panel
Publications
- X. Zhao, H. Wang, R. Curran, M.J.L. van Tooren, (2012) “Concurrent Aerospace Thermoplastic Stiffened Panel Conceptual Design and Cost Estimation using Knowledge Based
Engineering”, 19th ISPE International Conference on Concurrent Engineering, pp195-206
- H. Wang, X.Zhao, G. La Rocca, R. Curran and M. J. L. Van Tooren (2012)” Parametric Modeling of Fuselage Panels for Structural Analysis and Cost Estimation”, 3rd Aircraft Structural
Design Conference
- R.Van Dijk, X.Zhao, H.Wang, F.Van Dalen (2012) “Multidisciplinary Design and Optimization Framework for Aircraft Box Structures”, 3rd Aircraft Structural Design Conference
d)