Team Wrecked

Week 9 Deliverables: Engineering Analysis

Energy Experiment

h = 3 ft

w = 2.5 lb

d = 25 ft

Weight was dropped from a fixed pivot point like a pendulum

Wanted to achieve a distance of 25 ft.

Experimental Results

4

5

6

7

8

9

10

11

10 15 20 25 30 35

Distance (ft)

Pot

entia

l Ene

rgy

(lbf*

ft)

Spring-loaded Arm - FBD

Shear and Bending Diagrams

Powered Arm - FBD

Shear and Bending

Governing Equations

I

My

bhI

FrT

kxF

kxmghU

spring

3

2

2

1

2

1

EES Equations

Important EES Results

• Spring constant, k = 129.7 lbf/in.

• Max spring force = 152.8 lbf

• Torque required by motor = 229.2 lbf-in.

• Max beam stress, σ = 24.7 ksi

Material Selection

Tensile Yield Strengths

  σ (ksi)

Engineering Plastics ~ 2.5-17

Wrought Aluminum Alloy ~ 5-73

Aluminum Casting Alloy ~ 9-30

Copper Alloys ~ 10-60

Cast Iron ~ 47-120

Stainless Steel ~ 40-195

Carbon Steel ~ 26-118

New Design