Elastic deflections

Question 1

What happens when a beam is subjected to two-point loads?

Answer 1

Will deflect

Question 2

Beams subjected to bending will be accompanied by what?

Answer 2

• A deflection, u
• A rotation, θ

Question 3

How is θ measured?

Answer 3

From the horizontal axis

Question 4

How can flexural stiffness be determined?

Answer 4

E*I

Question 5

How can you calculate radius of curvature?

Answer 5

EI/M

Question 6

How can rotation θ be calculated?

Answer 6

θ ≈ du/dx = ∫M/EI *dx

Question 7

How can we obtain the vertial deflection?

Answer 7

Integrate rotation

Question 8

What is a sagging moment know as?

Answer 8

A positive moment

Question 9

What is a hogging moment known as?

Answer 9

“negative” moment

Question 10

What is a downward deflection known as?

Answer 10

“negative” deflection

Question 11

What is a upward deflection known as?

Answer 11

“positive” deflection

Question 12

What is a downward rotation known as?

Answer 12

“negative” slope

Question 13

What is an upward rotation known as?

Answer 13

“positive” slope

Question 14

What are boundary conditions?

Answer 14

Locations in the beam where the slope and deflection are known

Question 15

When are Macaulays brackets used?

Answer 15

Macaulay brackets are special expressions that are denoted using square brackets for expressions beyond x

Question 16

What happens if the value in the Macaulay bracket is negative?

Answer 16

When the equation within the bracket results in a negative value, the whole bracket is set to a value of zero and ignored