Abstract The single step perturbation method is a recently developed structural dynamic modification technique. In the present work, this has been applied to complex structures. A typical machine tool structure in form of an F structure is considered and eigenvalue and response reanalysis are carried out for this structure when modified by constrained viscoelastic damping layer treatment. A comparison of results is made for cases using the single step perturbation method, with the erstwhile perturbation method and the re-solved results, i.e., results obtained by repeated solution. Comparison of computational times taken are also indicated. A variation of coverage ratio is considered for the above structure and the variation in natural frequencies and loss factors in case of free vibration, variation in resonant frequencies and amplitudes in case of forced vibration are also studied.