| Abstract: | When solving the equations of structural dynamics using direct time integration methods, algorithmic damping is useful to control spurious high-frequency oscillations. Ideally, an algorithm should possess asymptotic annihilation of the high-frequency response, i.e. spurious oscillations are eliminated after one time step. Numerous one-step algorithms, spectrally equivalent to linear multistep (LMS) methods, have been developed which include controlled numerical dissipation. This paper proves that the only unconditionally stable, second-order accurate, 3-step LMS method possessing asymptotic annihilation is Houbolt's method, which is known to be overly dissipative in the low-frequency regime. Thus, using LMS methods, obtaining asymptotic annihilation with little low-frequency dissipation requires at least a 4-step method. |
