Beam Deflection, I & E

A mathematical property of a cross section (measured in inches) that gives important information about how that cross-sectional area is distributed about a centroidal axis:

• Centroid Principles

• Moment of Inertia

• Modulus of Elasticity

• Beam Deflection

The ratio of the increment of some specified form of stress to the increment of some specified form of strain. Also known as coefficient of elasticity, elasticity modulus, elastic modulus:

• Centroid Principles

• Moment of Inertia

• Modulus of Elasticity

• Beam Deflection

Object’s center of gravity or center of mass.

• Centroid Principle

• Moment of Inertia

• Modulus of Elasticity

• Beam Deflection

Beam A and B are the same material and same dimensions. What distinguishes beam A from beam B?

• Beam A will have a greater resistance to bending because it has a lower moment of inertia.

• Beam A will have a greater resistance to bending because it has a higher moment of inertia.

• Beam B will have a greater resistance to bending because it has a lower moment of inertia.

• Beam B will have a greater resistance to bending because it has a higher moment of inertia.

Correct formula for calculating beam deflection:

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• 
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Given the information above, calculate the beam deflection for Beam A:

• .12 inches

• 1.39 inches

• .53 inches

• .24 inches

What is TRUE about Moment of Inertia (I)?

• In general, a higher moment of inertia produces a greater resistance to deformation.

• In general, a lower moment of inertia produces a greater resistance to deformation.

• In general, a higher moment of inertia produces a reduced resistance to deformation.

Using the equation for the moment of inertia above, find the base of a piece of wood that has moment of inertia 21 and height 5.5.

• 1.5

• 2

• 1

• 15

Does the top plank or bottom plank seem to have a higher modulus of elasticity?

• Top plank

• Bottom plank

• They are the same