Topology Optimization of a Steel-Aluminium-Hybrid for an ...
Topology Optimization of a Steel-Aluminium-Hybrid for an ...
Topology Optimization of a Steel-Aluminium-Hybrid for an ...
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Altair EHTC<br />
<strong>Topology</strong> <strong>Optimization</strong> <strong>of</strong> a <strong>Steel</strong>-<strong>Aluminium</strong>-<strong>Hybrid</strong> <strong>for</strong> <strong>an</strong><br />
Automotive Body Structure<br />
Speaker: D. Funke (Imperia GmbH)<br />
November 4th, 2009<br />
Ludwigsburg
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Agenda<br />
1. Common <strong>Hybrid</strong> Structures in today‘s Automotive Industry<br />
2. The <strong>Steel</strong>-<strong>Aluminium</strong>-<strong>Hybrid</strong>: VarioStruct<br />
3. Principle <strong>of</strong> <strong>Hybrid</strong> Structures<br />
4. Loadcases<br />
5. Dimensioning <strong>of</strong> the Sheet Metal Pr<strong>of</strong>ile<br />
6. Analogous Model <strong>for</strong> Rib <strong>Optimization</strong><br />
7. Dimensioning <strong>of</strong> Rib Structure with Submodel<br />
8. Dimensioning <strong>of</strong> Rib Structure with Component Model<br />
9. The VarioStruct Ro<strong>of</strong> Crossmember<br />
10. Mech<strong>an</strong>ical Properties <strong>of</strong> the VarioStruct Ro<strong>of</strong> Crossmember
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1. Common <strong>Hybrid</strong> Structures in today‘s Automotive Industry<br />
Application <strong>of</strong> metal-plastic-hybrid in<br />
<strong>an</strong> automotive body<br />
Source: L<strong>an</strong>xess Source: Honda<br />
• Ro<strong>of</strong> crossmember with master<strong>for</strong>med<br />
plastic rein<strong>for</strong>cement<br />
• Form closure<br />
<strong>Steel</strong>-lightmetal-composite casting<br />
in motor m<strong>an</strong>ufacture<br />
• Engine block with cast-in cylinder<br />
liners<br />
• Form closure<br />
• Metallic continuity<br />
� Thin-walled steel-lightmetal-hybrids <strong>for</strong> automotive body structures
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2. The <strong>Steel</strong>-<strong>Aluminium</strong>-<strong>Hybrid</strong>: VarioStruct<br />
Material 1 (Sheet)<br />
• property pr<strong>of</strong>ile 1<br />
+<br />
• <strong>Aluminium</strong> rib structure casted in steel sheet pr<strong>of</strong>ile<br />
• Adv<strong>an</strong>tage <strong>of</strong> both material will be taken<br />
• Connection steel ↔ casting<br />
• Complex cast structures with sheetmetals possible<br />
• High potential <strong>of</strong> integration<br />
Material 2 (Cast)<br />
• property pr<strong>of</strong>ile 2<br />
• Possible to combine other materials<br />
master<br />
<strong>for</strong>ming<br />
<strong>Steel</strong>-<strong>Aluminium</strong>-<br />
<strong>Hybrid</strong><br />
metallic continuity<br />
<strong>for</strong>m closure<br />
continued sheet metal<br />
cast c<strong>an</strong>tilever<br />
assembly<br />
attachment<br />
extrusion joint<br />
frictional<br />
connection
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3. Principle <strong>of</strong> <strong>Hybrid</strong> Structures<br />
F<br />
Conventional<br />
sheet metal structure<br />
F<br />
<strong>Hybrid</strong><br />
structure<br />
• Prevention <strong>of</strong> local buckling<br />
• Limitation <strong>of</strong> plastic hinges<br />
� less weight<br />
� higher energyabsorption<br />
supporting<br />
effect<br />
Maximum supporting effect:<br />
� Optimal dimensioning <strong>of</strong> cast ribs<br />
� Design proposal: topology optimization with OptiStruct<br />
Conventional sheet metal structure<br />
cross section<br />
height<br />
<strong>Hybrid</strong> structure<br />
cross section height
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4. Loadcases<br />
Example <strong>of</strong> Submodel<br />
• Ro<strong>of</strong> impact<br />
• Torsion<br />
Design space<br />
• Pole impact<br />
F<br />
Combination <strong>of</strong> all<br />
loadcases<br />
F<br />
F<br />
F<br />
Component Model<br />
• 3-point-bending, centric<br />
• 3-point-bending, excentric<br />
F<br />
F<br />
• Axial compression<br />
Combination <strong>of</strong> all<br />
loadcases<br />
F
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5. Dimensioning <strong>of</strong> the Sheetmetal Pr<strong>of</strong>ile<br />
• <strong>Topology</strong> optimization (solids)<br />
• Submodel<br />
• Combination <strong>of</strong> all loadcases<br />
Result <strong>of</strong> topology optimization Derived pr<strong>of</strong>ile <strong>of</strong> sheetmetal<br />
� Next step: dimensioning <strong>of</strong> rib structure
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6. Analogous Model <strong>for</strong> Rib <strong>Optimization</strong><br />
• Application <strong>of</strong> volume elements<br />
� Elements ↑, calculation time ↑<br />
� Maximum rib thickness ↔ element size (Maxdim = 6 * l c )<br />
• Remedial action with approach by Hartzheim [1]<br />
• Design space: shell elements<br />
• Approximation <strong>of</strong> volume: rigid bars<br />
� Elements ↓<br />
� High resolution with small elements<br />
� � thin ribs<br />
[1] HARTZHEIM, Lothar: Strukturoptimierung, Verlag Harri Deutsch, Fr<strong>an</strong>kfurt, 2008<br />
shell layer 1, design space<br />
rigid bar<br />
shell layer 2, sheetmetal, nondesign space
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7. Dimensioning <strong>of</strong> Rib Structure with Submodel<br />
• <strong>Topology</strong> optimization (shells)<br />
• Submodel<br />
• Combination <strong>of</strong> all loadcases<br />
• Suitable <strong>for</strong> outer rib structures<br />
Iteration 10<br />
Iteration 20<br />
Iteration 30<br />
derived structure<br />
design space<br />
� Next step: dimensioning <strong>of</strong> rib structure in crossmember‘s middle area
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8. Dimensioning <strong>of</strong> Rib Structure with Component Model<br />
F<br />
• <strong>Topology</strong> optimization (shells)<br />
• Component model<br />
• Combination <strong>of</strong> all loadcases<br />
• Suitable <strong>for</strong> inner rib structures<br />
F<br />
F<br />
ribs derived from first optimization<br />
Iteration 15<br />
Iteration 25<br />
Iteration 36<br />
design space<br />
� Next step: derive initial rib structure <strong>for</strong> nonlinear optimization
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9. The VarioStruct Ro<strong>of</strong> Crossmember<br />
component model<br />
loadcases, constrains, designspace, ...<br />
topology optimization, solids<br />
topology optimization, shells<br />
derive rib structure<br />
submodel<br />
initial design<br />
nonlinear optimization (crash loadcases)<br />
final design
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10. Mech<strong>an</strong>ical Properties <strong>of</strong> the VarioStruct Ro<strong>of</strong> Crossmember<br />
<strong>Hybrid</strong> structure Conventional sheetmetal structure
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11. Mech<strong>an</strong>ical Properties <strong>of</strong> the VarioStruct Ro<strong>of</strong> Crossmember<br />
• 3-point-bending test<br />
Force [-]<br />
1.5<br />
1.0<br />
0.5<br />
0.0<br />
Conventional<br />
Original<br />
VarioStruct<br />
0 50 100<br />
Displacement [mm]<br />
120%<br />
100%<br />
80%<br />
60%<br />
40%<br />
20%<br />
0%<br />
75% 106% 112%<br />
Mass Maximum<br />
Force<br />
Absorbed<br />
Energy
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Th<strong>an</strong>ks to BMBF<br />
Th<strong>an</strong>ks to project partners<br />
Th<strong>an</strong>ks <strong>for</strong> support in research project from
Page 15<br />
11/04/2009<br />
Imperia GmbH<br />
Automotive Engineering<br />
Soerser Weg 9<br />
D-52070 Aachen<br />
Dipl.-Ing. (FH) David Funke<br />
Tel.: +49 - (0)2 41 - 6 08 33-15<br />
Fax: +49 - (0)2 41 - 6 08 33-20<br />
Mail: funke@imperia.info<br />
Dipl.-Ing. Niels Nowack<br />
Tel.: +49 - (0)2 41 - 6 08 33-14<br />
Fax: +49 - (0)2 41 - 6 08 33-20<br />
Mail: nowack@imperia.info<br />
Th<strong>an</strong>k you <strong>for</strong> your attention!
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