Truss Deflection - Virtual Work Method

How do we determine node deflection for a truss? Virtual work method is the most common solution to accomplish task.

Under real load case, forces developed in truss members are calculated, using either method of joint or method of section. Then, we assign a unit virtual load on the interested node and perform same calculation procedure to determine the member forces under this case.

After that, we need to identify the length, cross sectional area and modulus of elasticity of members. By using a dedicated equation, we can solve for the deflection at target node. For the ease of calculation, these values should be presented in table form.

The following introduces the calculation of truss deflection using virtual work method. Watch the video above for full details.