1

Dr.

Ali

Al-G

adhi

b

Lecture No. 21Lecture No. 21

To be able to find Shear Flow and

Shear Stress at glue and at nails.

Ib

VQ

I

VQq

2

Dr.

Ali

Al-G

adhi

b

• Shear Flow at a Particular Junction

3

Dr.

Ali

Al-G

adhi

b

The beam is constructed from four boards glued together. If it is subjected to a shear of V = 850 kN, determine the shear flow at B and C that must be resisted by the glue.

4

Dr.

Ali

Al-G

adhi

b

m01.0m250.0m01.0m125.0m01.0m3.02

m01.0m250.0m305.0m01.0m125.0m205.0m01.0m3.0m15.02

A

Ayy

Section Properties.

5

Dr.

Ali

Al-G

adhi

b

Shear Flow.

Ans.... m/MN0498.0q and m/MN31.1q

m/MN0995.0m1052.87

m1001025.0kN850

I

VQq

m/MN62.2m1052.87

m10270.0kN850

I

VQq

CB

46

33C

C

46

33B

B

6

Dr.

Ali

Al-G

adhi

b

A box beam is to be constructed from four boards nailed together. If each nail can support a shear force of 30 N, determine the maximum spacing s of nails at B and at C so that the beam will support the vertical force of 80 N.

7

Dr.

Ali

Al-G

adhi

b

Internal Shear.

8

Dr.

Ali

Al-G

adhi

b

Shear Flow.

Ans..

Ans..

9

Dr.

Ali

Al-G

adhi

b

Nails having a total shear strength of 40 N are used in a beam that can be constructed either as in Case I or as in Case II, If the nails are spaced at 9 cm, determine the largest vertical shear that can be supported in each case so that the fasteners will not fail.

10

Dr.

Ali

Al-G

adhi

b

11

Dr.

Ali

Al-G

adhi

b