an ultralight aircraft design needs a critical weight reduction a trade study is performed using Solidworks Simulation

1. Extreme weight reduction using
expanded aluminum mesh
FEA analysis of a
structural member
8/31/2016
Don Blanchet
3B Associates
dwb3298@verizon.net

2. Goals
 Reduce the weight of a small but
critical motor mount component for a
light single person aircraft.
 Due to cost limitations a graphite fibre
structure was ruled out.
 Trade study of original solid machined
design with metal mesh design.

3. Location of critical component a
part of the engine mount assembly

4. Solid plate design
6061-t6 aluminum
~ 7 x 4 x 0.5 inches Weight = 0.62 lbs

5. FEA mesh

6. Fixed boundary
conditions

7. First resonant frequency
920 hz

8. Static stress = 15,750 psi
Oposing 100 lb loads

9. Elastic twist deformation
= .080 inch

10. Aluminum mesh core
design – vacuum brazed
.010 thick expanded metal mesh
.010 thick cover plates
Brazed to mesh both sides
Total Weight = 0.23 lbs

11. FEA mesh with covers

12. FEA mesh without covers

13. First resonant frequency
= 1329 hz

14. Static stress = 32,330 psi

15. Elastic twist deformation
= .150 inch

16. Results summary
Analysis
case
Resonant
Frequency
hz
Maximum
Stress
psi
Maximum
elastic
Deflection
inch
Weight
lbs
Factor of
Safety
Yield
strength =
42,000 psi
Solid
machined
plate
920 15,750 0.080 0.62 2.7
Expanded
aluminum
core
1329 32,330 0.150 0.23 1.3

17. Conclusions
 There is a 63% weight savings using
the vacuum brazed expanded metal
core design.
 The stress design margin will be
reduced to 30%.
 Very critical weight savings can be
attained a at reasonable cost increase.