Morphing aircraft and morphing structure concepts have always interested many researchers and aircraft designers because of its ability to improve the overall performance of an aircraft. One of the most beneficial morphing concepts is the span morphing concept which improves the range and endurance by increasing the span of a morphing aircraft wing during cruise and improves the manoeuvrability performance by decreasing the span of a wing. A common mechanism which can be used to achieve span morphing is the telescopic mechanism. This mechanism consists of two beams with one being a main or primary support beam (cantilever type) and the other secondary beam extending out or retracting inside the primary support beam. Thus by moving the secondary beams over the primary support beam, the span of the beam can be increased or decreased.
When the secondary beam traverses along the primary beam, the overall load pattern acting on the primary beam changes. Such a movement of secondary beams can be modelled as an equivalent moving-loads (.ie moving forces, moving bending moments, and moving torque) acting on the supporting beam. This movement of equivalent load, with a definite velocity, induces vibration in the primary beam. This results in a necessity to study the dynamic effects of moving loads and limit the vibrations induced on the beam. The beam is modelled using the Rayleigh beam theory to incorporate the rotary inertia effects. The bending and torsional response are decoupled and studied separately. The moving loads are modelled as three types: (i) Non-Inertia, Time Constant Load, (ii) Non-Inertia, Time Varying Load and (iii) Inertia load. The response of the beam is studied primarily in terms of Dynamic Amplification factor (DAF) and velocity of travel.