The document discusses the design and cost analysis of a truss structure, focusing on joint locations, dimensions, and material selection. Load calculations determine the forces acting on various members of the structure, categorizing them into compression and tensile forces. Final remarks indicate potential failure points in the design based on the stress analysis conducted.

1. Structure Standing Still:
The Statics of EverydayThe Statics of Everyday
Objects
by Dr. Dan Dickrell
Project Final Submission

2. Design Scratch:
My design labeling the joint locations with letters, and showingMy design labeling the joint locations with letters, and showing
important dimensions locating the joints within the design.

3. Total cost of my design:y g
Given at no cost a pin joint at B, two freep j ,
reaction points, a pin joint at A and a roller at C.
AB=BC=DE=4 m
Cost= 3*(75+4^4) = $993
AD=BD=BE=CE=2.31 m
Cost 4*(75+2 31^4) $414Cost= 4*(75+2.31^4) = $414
Total member cost= $1407
Joint (A B C) = $0 (Free)Joint (A, B, C) $0 (Free)
Pin joint (D, E) = $50
Total pin joint cost =$50*2= $100p j
Total truss (bridge) cost= 1407+100= $1507

4. Load Calculation:
Blue member (AD, DE, CE) =Compression buckling
Red member (AB, BC, BD, BE) = Tensile yielding
Forces in members
AB=BC=DE=8.66 KN
AD=BD=BE=CE= 10 KN
AB=8.66 KN= (Tensile yielding)
BC=8.66 KN= (Tensile yielding)
DE=8.66 KN= (Compression buckling)
AD=10 KN= (Compression buckling)
BD=10 KN= (Tensile yielding)
BE=10 KN= (Tensile yielding)
CE= 10 KN= (Compression buckling)

5. Stress Analysis:
Material Selection:
Truss Material: Aluminum alloy 6061-T6
Shape: Hollow Pipe
Yield strength: 241 MPa = 241000 KN/m²
Factor of safety= 2 (Assumed)
Equation:
Yield strength = Load* Factor of safety / Sectional Area
After calculation:
For AD=BD=BE=CE= 10 KN;
Outer diameter= 50 mm
Inner diameter= 48.9 mm
For AB=BC=DE=8.66 KN;
Outer diameter= 50 mm
Inner diameter= 49 mm

6. Final Remarks:
Final Remarks:Final Remarks:
AD & CE will fail first due to
Compression buckling &Compression buckling &
BD & BE will fail first due to tensile
i ldiyielding.

7. Thanks