Question

А)

Answer 1

Image of the plate is missing, so i have attached it.

Answer:

A) t = 7.854 mm

B) σ = 26.67 MPa

Explanation:

A) From shearing of rivet, formula for pressure is;

P = τ•A_rivets

Where;

τ is allowable stress

A_rivets is Area of rivet

We are given:

τ = 60 MPa

Diameter; d = 20 mm

A_rivets = πd²/4 = π × 20²/4 = 100π

Thus;

P = 60 × 100π

P = 6000π N

From bearing of plate material, we can calculate pressure as;

P = σ_b•A_b

We are given;

σ_b = 120 MPa

A_b is area of plate = 20t

Where t is the thickness

Thus;

6000π = 120 × 20t

t = 6000π/(120 × 20)

t = 7.854 mm

B) Largest average tensile stress is given by the formula;

σ = P/A

Where A = 110t - 20t

A = 90t

A = 90 × 7.854

Thus;

σ = 6000π/(90 × 7.854)

σ = 26.67 MPa