Question

A load P is applied horizontally while the other end is fixed to a structure. A load P is applied horizontally while the other end is fixed to a structure. How many bolts are required to make the assembly safe? Use 8 mm bolts (M8-1.25) that yield at 0.5 MPa. (You must provide an answer before moving to the next part.)

Answer 1

The number of bolt is 4.

Step-by-step explanation:

Given that,

`\tau = 0.5\ MPa`

distance = 8 mm

Suppose, Load P = 205 N

We need to calculate the shear area of bolt

Using formula of shear stress

`\tau=(P)/(A)`

Here is double shear.

So,
`\tau` will be double.

`A=(P)/(2\tau)`

Put the value into the formula

`A=(205)/(2*0.5*10^(6))`

`A=205*10^(-6)\ m^2`

We need to calculate the area of one bolt

Using formula of area

`A'=(\pi)/(4)d^2`

Put the value into the formula

`A'=(\pi)/(4)*(8*10^(-3))^2`

`A'=50.26*10^(-6)\ m^2`

We need to calculate the number of bolt

Using formula of number of bolt

`n=(A)/(A')`

Put the value into the formula

`n=(205*10^(-6))/(50.26*10^(-6))`

`n=4.0`

Hence, The number of bolt is 4.