Example Question

Example Question

Beams – Internal Forces example question

Find the internal forces at the section cut C-C, at x = 3m.

Find the internal forces at the section cut C-C, at x = 3m.

Click below to show answer. X

Step 1:
Draw FBD of beam and replace distributed load with equivalent force

Step 1:
Draw FBD of beam and replace distributed load with equivalent force

Beams – Internal Forces solution step 1

Step 2:
Solve for reactions using equations of equilibrium

Step 2:
Solve for reactions using equations of equilibrium

Beams – Internal Forces solution step 2

Step 3:
Draw FBD for section cut

Step 3:
Draw FBD for section cut

Beams – Internal Forces solution step 3

Step 4:
Solve for internal forces using equations of equilibrium

Step 4:
Solve for internal forces using equations of equilibrium

Beams – Internal Forces solution step 4

Useful formula:

Useful formula:

Beams – Internal Forces formula

Let's look at what happens when we consider the right section cut instead:

Let's look at what happens when we consider the right section cut instead:

Click below to show answer. X

Step 3:
Draw FBD for section cut

Step 3:
Draw FBD for section cut

Beams – Internal Forces solution step 3 - right section cut

Step 4:
Solve for internal forces using equations of equilibrium

Step 4:
Solve for internal forces using equations of equilibrium

Beams – Internal Forces solution step 4 - right section cut

Now that you've mastered this question, you can try Question 1.