Full length articleInstability of a delaminated composite beam subjected to a concentrated follower force

•A simple analytical solution is presented for instability of delaminated composite beam.•Delaminated composite beam is subjected to a concentrated follower force.•Effect of delamination location and length and laminate stacking sequence are investigated.•Delamination has different effect on vibration frequency, buckling and flutter load of the beam.

Vibration, buckling and flutter instability of delaminated composite beams are studied in this paper. An analytical solution is presented for instability of a composite beam with a single delamination subjected to concentrated follower force. Using Euler-Bernoulli beam theory and Classical Lamination Theory, equation of motion of a delaminated beam is derived and solved analytically for free vibration, buckling and flutter instability. After validating the results, effect of delamination location, delamination length and stacking sequence on fundamental frequency, buckling load and flutter load are studied. Results show that for a cantilever beam, when delamination moves from surface of the beam to its mid-plane, fundamental frequency and buckling load decreased while flutter load is increased.