 The Decoupling of Damped Linear Systems in Oscillatory Free Vibration by Fai Ma, Ali Imam and Matthias Morzfeld

Journal of Sound and Vibration324,408–428(2009); title page gives full bylines Fai Ma, Ali Imam and Matthias Morzfeld and their Mechanical Engineering, UC Berkeley affiliation. Sections2.1–2.2, modal transformation and classical damping, including equation(12), the commutation criterion; section3.1, equation(14), the damped quadratic eigenvalue problem. Repository metadata and article title page agree on authors and publication year.