Time-history analysis provides for linear or nonlinear evaluation of dynamic structural response under loading which may vary according to the specified time function. Dynamic equilibrium equations, given by K u(t) + C d/dt u(t) + M d2/dt u(t) = r(t), are solved using either modal or direct-integration methods. Initial conditions may be set by continuing the structural state from the end of the previous analysis. Additional notes include:
- Step Size – Direct-integration methods are sensitive to time-step size, which should be decreased until results are not affected.
- HHT Value – A slightly negative Hilber-Hughes-Taylor alpha value is also advised to damp out higher frequency modes, and to encourage convergence of nonlinear direct-integration solutions.
- Nonlinearity – Material and geometric nonlinearity, including P-delta and large-displacement effects, may be simulated during nonlinear direct-integration time-history analysis.
|Time-history analysis first steps||Overview of the procedure for time-history analysis.||SAP2000|
|Vibrating-machinery steel skid on piles||This tutorial demonstrates the modeling of vibrating machinery and its connection to a steel-skid structural system.||SAP2000|
|Human-induced vibrations||The modeling and analysis of human-induced vibrations due to footfalls or another type of impact.||SAP2000|
|Multi-pendulum model (Newton's cradle)||Model a pendulum system in SAP2000 using large-displacement time-history analysis.||SAP2000|
|Steady-state vs. time-history analysis||Test problems to demonstrate the differences and similarities between steady-state and time-history analyses.||SAP2000|
- Multi-support excitation article