Embed Size (px)
DESCRIPTION
In modern day industry, an emphasis of lean engineering has taken place in order to save time and resources while delivering better products than competitors. Furthermore, great strides in production and manufacturing have raised efficiency and saved companies time and money. However, testing and certification, although essential, can be a costly procedure in between the stages of design and production. In an effort to enhance and supplement the structural testing methods, specifically crash analysis, a simplified yet accurate FEA modeling method is developed to better understand a design performance during physical testing. However, the methodology will not be a substitute for real world certification testing, but rather a means to save time and money so as to offer performance and design insight. A critical area of performance is crash test analysis. The modeling method in this presentation was based upon crash conditions referenced from FAR 25.562 as well as physical test methods for crash analysis. Furthermore, this modeling method was directly compared to real world test data. The crash modeling utilizes HyperMesh, HyperCrash, and LS-DYNA so as to offer insight into structural performance.
Citation preview
Finite Element Modeling and Testing of
Aerospace Seats Under Crash Conditions
2012 Americas HyperWorks Technology Conference
Fady Barsoum Ph.D
Benjamin Walke (presenting)
Aditya Gupte
1
Talking Points
Motivation
Simulation Standards
Process Flowchart
Key Functions
Results
2
Motivation
Step-by-Step modeling method for effective
crash simulation
Save time required to simulate a high-g crash
in conjunction with testing
Allow for simulation of design changes to
improve safety
3
Aircraft Seats
Gulfstream
aircraft seats
Pilot &
Passenger
4
Simulation Standards
Simplify the structure
and crash conditions with
the aim of a basic model
Cushions removed
2-point buckle
Head on crash
16G in 90ms
170 lb Dummy
5
Simulations Standards
6
Flowchart CAD
Pre-Processing Explicit Dynamic
*Defeaturing *Mesh *BC *Prescribed Motion
Solver
Post-Processing
HyperMesh HyperCrash
7
LS-DYNA
Geometry
8
Geometry
9
2D Geometry Integration
10
Initial Mid-Surface
11
Pre-Procesing in HyperMesh
12
Hole Removal
Fillet and Round Defeaturing
Automatic MidSurface
Mesh
13
HyperCrash
Contact Modeling
Dummy and Seat
Belt and Dummy
Seat Components
Boundary Conditions
Prescribed Motion
14
Contact Modeling
15
Tied Surface to Surface
Tied Shell Edge to Surface
Automatic Surface to Surface
Automatic Nodes to Surface
Boundary Conditions
16
Boundary Conditions set to allow only for translational motion in the aft facing direction
17
-17
-15
-13
-11
-9
-7
-5
-3
-1
0 50 100 150 200
G
Time (milliseconds)
Sled Acceleration
Post-Processing
18
0 ms 100 ms 50 ms
Testing
19
Future Analysis and Testing
20
Conclusion
Functions in HyperMesh and HyperCrash
greatly reduced our time to pre-process.
We are close to the validation of simulation
data with test data, however more work must
be done.
21
References
Bala, Suri. Jim Daly. “General Guidelines for Crash Analysis in LS-
DYNA”
Bhonge, Prasannakumar. “A Methodology for Aircraft Seat Certification
By Dynamic Finite Element Analysis.”
“Getting Started with LS-DYNA.” (LSTC)
LS-DYNA Keyword User’s Manual (LSTC)
22
