LONDON BRIDGES

Engineering Cohort

PROJECT ENGINEERS

Bobbi Peery & Tom Wolfe Mustang Canyon Ridge

Rhana Vickers Edmond Sequoyah

Katherine Brooks Norman Whittier

Jessica Wetherington & Ann Williams PC Kenneth Cooper

Dr Chris Ramsmeyer – Mentor

BRIDGES COME IS DIFFERENT FLAVORS

BRIDGE PARTS HAVE NAMES

MEMBERS CAN FAIL MANY WAYS

Compression - Red Tension - Blue

BRIDGES CAN FAIL MANY WAYS

Lateral Torsional Buckling aka twisting

Joints

GETTING DOWN TO BUSINESS

How does increasing the height of a bridge affect the stress on a chord?

How does increasing the length of a bridge affect the stress on a chord?

MODELS ARE MOST COST EFFICIENT

Westpoint Bridge Designer 2014 – Free!

MODELS ARE MOST COST EFFICIENT

Pasco Model Kit with Sensor Cleaner data, decrease workmanship error,

reusable

NEXT STEP - WOOD

THE PLAN

Build and test 3 bridges of increasing length.

Predict the value of a 4th length Build and test the 4th length Compare predicted and actual value

Wood is much more lifelike!

10 15 20 25 30 350

5

10

15

20

25

30

35

40

f(x) = 128.811331572356 x^-0.487489176056865R² = 0.986708249947869

Bridge Length vs Breaking Stress

Series1Power (Series1)PredictionActual

Length of Bridge (cm)

Ste

ss (

lb)

LESSONS LEARNED

Getting bridges to fail in the correct place is harder than we originally thought

Using equipment correctly in key The real world is not as nice as

analytical models Bass wood might look like Balsa wood,

but does not break the same

LESSONS LEARNED

How to graph in Excel Experimental data can not be altered! All data should go in lab book Lab books should be in pen – may be

legal document

INFORMATION THAT MAY COME IN HANDY WHEN TAKING THE POST TEST QUESTIONS

There are over 23,000 bridges in Oklahoma, including 6-7,000 highway bridges

As the length of a bridge increases, the stress (compression, tension) needed to break the bridge decreases The relationship is power series

As the height of a bridge increases, the stress (compression, tension) needed to break the bridge increases The relationship is a power series (negative

exponent)