2. Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lab 5P. 1Autumn Quarter Material Joining and Beam Bending Lab 5

3. Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lab 5P. 2Autumn Quarter Beam Deflection Every object acts as a spring – it will deflect when a force is applied Extent of deflection depends on force applied, material properties and object shape

4. Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lab 5P. 3Autumn Quarter Differences in Deflection Although the beams have the same cross-sectional area, the moments of inertia are different Because the moments of inertia are different, the beams deflect different amounts

5. Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lab 5P. 4Autumn Quarter Moments of Inertia A larger moment of inertia means that the beam will be more resistant to deflection I = Area Moments of Inertia (depends on object shape) b h

6. Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lab 5P. 5Autumn Quarter Strain:Stress:(lb/inch 2 ) A (cross-sectional area) P (applied force) L (original length)  (deflection from original length) Stress and Strain: Simple Definitions

7. Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lab 5P. 6Autumn Quarter Stress vs. Strain Curves: Young’s Modulus (slope of curve or material stiffness) Linear Portion (Hooke’s Law): Strain:Stress:(lb/inch 2 ) Stress and Strain: Simple Definitions

8. Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lab 5P. 7Autumn Quarter Cantilever Beam Bending Equation In this lab, you will measure the deflection d for various loads P. Using this information and other measurements, calculate Young’s modulus E for each beam. P L s y x

9. Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lab 5P. 8Autumn Quarter Material Joining A separate demonstration will be given on the welding procedure The final product will form a ‘T’ shape

10. Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lab 5P. 9Autumn Quarter Things to Consider: How will joining the beams through welding affect the overall stiffness? Is there any advantage to choosing a more flexible material such as aluminum over a stiffer material such as steel? Hypothetically, if you were to design a 9x9” robot spring quarter, which materials do you feel would be most suited for use? Which shapes would form a stiffer chassis?

11. Engineering H191 - Drafting / CAD Gateway Engineering Education Coalition Lab 5P. 10Autumn Quarter Questions ?