# Homework Help: Finding Forces in a tie rod.

1. Jun 5, 2009

### falconed

Hey all!

I have a project question I'm struggling on:
The rigid structure ABD in Figure 1 is supported at B by a 35-mm-diameter tie rod (1)
and at A by a 30-mm-diameter pin used in a single shear connection. The tie rod is
connected at B and C by 24-mm diameter pins used in double shear connections. Tie
rod H has yield strength of 250 MPa, and each of the pins has ultimate shear strength
of 330 MPa. A concentrated load of P = 50 kN acts at D. Determine:
(a) The normal stress in rod (1).

http://img269.imageshack.us/img269/2382/question1a.jpg [Broken]

My main problem is I am unsure where to place the reaction forces with regards to pins so that I can use moments and forces in the x and y direction to determine the force in the rod. Once i know this I can find the stress in the rod.

Any help would be great!

Last edited by a moderator: May 4, 2017
2. Jun 5, 2009

### nvn

Place the reaction forces at the supports, A and C. Solve for the reaction forces using statics.

3. Jun 7, 2009

### djeitnstine

Also your tie rod (1) is a two force member.

4. Jun 7, 2009

### elbarto

Try making a cut in member (1) and then take the moments about A. You should be able to solve for the axial force directly by using you 3 equations of equilibrium.

Elbarto