structures pdr 1 team boiler xpress oneeb bhutta matthew basiletti ryan beech micheal vanmeter...
DESCRIPTION
Topics of Discussion Weight Estimation Center of Gravity Parts Location Landing gear systemTRANSCRIPT
Structures PDR 1
Team Boiler Xpress
Oneeb Bhutta Matthew Basiletti
Ryan BeechMicheal VanMeter
October 12, 2000
Topics of Discussion
Aircraft Weight Wing Weight EstimationStructural Material Properties Wing, fuselage, podsWing layout SparsLoad Analysis Theoretical Model Maximum Bending Moment and
Deflections and Diagrams Test of Actual Wing
Topics of Discussion
Weight Estimation Center of Gravity Parts LocationLanding gear system
component Number Weight ea (oz) total component (oz) wt fractionrecvr (ea) 1 1.5 1.50 1.1servo (ea) 4 1 4.00 2.9data logger (ea) 1 16 16.00 11.4gyro and controller (ea) 1 3 3.00 2.1motor cells (1.4ah nicad) 10 1.3 13.00 9.3wire for motor (inches) 70 0.0317 2.22 1.6motor and gear box (ea) 1 11 11.00 7.8propeller (ea) 1 2 2.00 1.4speed controller (ea) 1 1.2 1.20 0.9wing (sq ft) 13.5 2.3 31.05 22.2pod (ea) 2 5 10.00 7.1Main fuselage (ea) 1 12 12.00 8.6landing gear/wheels (ea) 3 1.5 4.50 3.2horizontal tail (sq ft) 2.5 4.37904 10.95 7.8Vertical Tail (sq ft) 1.4 4.37904 6.13 4.4Boom (ft) 6 0.6 3.60 2.6Miscellaneous (oz) 1 8 8.00 5.7
Total Weight (lb) 8.76 lbwing loading 0.65 lb/sq ft
CLmax 1.53 Stall speed 19.16 ft/s
Airframe Weight 4.66 lb
Aspect Ratio 9 Chord -root (in) 17.20taper Ratio (tips) 0.6 -tip (in) 10.32
Span (ft) 11.02
Weight Build up
Aircraft Weight
Material lb/unit Amt reqd weight (oz)foam (per in^3) 0.013 1470 19.351/4x1/8 balsa (per in) 0.003 480 1.53micafilm (per sq.in) 0.001 3360 2.74
add for misc structure 6.00
Foam wingTotal wing Weight 29.61
Density (lb/sq ft) 2.28
Wing Weight Estimation
Structural Materials: Wing
Balsa•Light weight/very strong in compression and tension with the grain•Density = 11lb/ft3
•E= 625 ksi•Yield Stress = 1725 psi (Actual Test Result; Whiskey Tango Team, Spring 1999)
Styrene Foam•Easily worked with hotwire or cutting tools•Gives true airfoil shape •Works well in compression when load is well distributed-serves as shear member•Not strong enough for bending loads•Density = 1.42 lb/ft3
Fiberglass
•Good for complex shapes
•Strong
•Skills needed
•3 layers of 1.5 oz cloth with resin = 9 oz/sq. yd.
Carbon Fiber
•Booms
•Light weight & Strong
Structural Materials:
Fuselage and Pods
Wing Spar Box Structure
Rear spar for control surface hinges
Styrene wing core
Balsa spars carry bending load 0.375 in x 0.25 in
L.E. Reinforcement
Assumptions:
•Box beam (ease of analysis)
•Moment of Inertia (Stringers)
•Spars carry loads & positioned at max camber
Analysis of Loads
Model as cosine lift distribution
•Structural weights distributed along span•Method of Analysis (Theoretical Model)
)*cos(')( 22 b
xLxL dxLxCosLLbeam
L
)2
('0
Bending Moments
Maximum Moment = 25.86 lb/ft
Safety Factor = 2.5g * 1.5
Wing Deflection
Max Deflection = 1.93 inches
Stress in the Wing
Sigmamax = 1241 psiSigmacritical = 1725 psi
Reasons: Light Weight Structure (not Bulky) Safety Factor (worst case scenario) Wing Test
IyMmax
max
Sand Bags
Geometry and Configuration
Wing:•Sref = 13.5 sq.ft.•Span = 11 ft.•Aspect Ratio = 9•Taper Ratio = 0.6 tip section•Airfoil: S1220
Horizontal Stabilizer:•Area = 2.1 sq ft.•Span = 3.0 ft.
Vertical Stabilizer:•Total Area: 2.0 sq.ft.
11.1’
5.8’
Boiler Xpress