Beam Deflection - Virtual Work Method

Virtual work method operates based on the principle of conservation of energy. By determining the internal work done by the loading, we can calculate the beam deflection.

First, we need to determine the support reactions and internal moment function under actual loading condition. Then, we need to revisit our analysis aim and set the course for the next step. If we want to determine the displacement at one point, we will need to assign a unit virtual load at that point. On the other hand, we put a virtual moment there if we want to know its rotation.

Under the virtual loading condition, we determine the support reaction and then internal moment function as well. With the moment functions under both conditions, we can substitute it into a dedicated equation, and by solving it we obtain the answer we need.

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