Unit 2: Engineering Design Process

Foundations of Technology

Lesson 1: Engineering Design Process

Structural Efficiency

The Big Idea

Big Idea:

• The Engineering Design Process is a systematic, iterative problem-solving method that produces solutions to meet human needs and wants.

Who’s Stronger

• Who’s stronger, the elephant or the ant?

Who’s Stronger

Asian elephants are often employed to lift thousands of pounds of timber for logging efforts.

Yet, an ant is much stronger pound for pound.

An ant can easily lift many times its own body weight due to their small size which creates a greater cross sectional muscle mass

An ant is a more efficient worker

What is Efficiency?

Efficiency is a ratio of your output versus your input.

Efficiency is the ratio of the resources developed versus the resource supplied.

Basically, efficiency measures the extent to which your device is functioning in the best possible manner.

Structural Efficiency

• In structural engineering efficiency is measured as the weight being supported divided by the weight of the supporting structure.

Crane Boom Efficiency

For our crane boom:Efficiency = the breaking weight

the weight of the crane boom

The units must be the same!They will cancel out!Efficiency is a unit-less number (a ratio)