!DYNAMIC

Dynamic analysis control

!BOUNDARY, !CLOAD, and !DLOAD specify !AMPLITUDE; the time t for each amplitude must start at 0.0.

Parameters

TYPE = LINEAR    : Linear dynamic analysis
       NONLINEAR : Nonlinear dynamic analysis

** 2nd line and subsequent lines **

(2nd line) idx_eqa, idx_resp

Variable	Type	Description
idx_eqa	I	Solution method for the equation of motion (direct time integration) (default: 1) 1: Implicit method (Newmark-β method) 11: Explicit method (central difference method)
idx_resp	I	Analysis type (default: 1) 1: Time-history response analysis 2: Frequency-response analysis

When idx_resp=1 (time-history response analysis)

(3rd line) t_start , t_end , n_step, t_delta

Variable	Type	Description
t_start	R	Analysis start time (default: 0.0), unused
t_end	R	Analysis end time (default: 1.0), unused
n_step	I	Default number of substeps when !STEP is omitted or for backward compatibility (default: 1)
t_delta	R	Default time increment when !STEP is omitted or for backward compatibility (default: 1.0)

(4th line) gamma , beta

Variable	Type	Description
gamma	R	Parameter γ of the Newmark-β method (default: 0.5)
beta	R	Parameter β of the Newmark-β method (default: 0.25)

(5th line) idx_mas ,idx_dmp , ray_m ,ray_k

Variable	Type	Description
idx_mas	I	Mass-matrix type (default: 1) 1: Lumped mass matrix 2: Consistent mass matrix
idx_dmp	I	1: Rayleigh damping (default: 1)
ray_m	R	Rayleigh-damping parameter Rm (default: 0.0)
ray_k	R	Rayleigh-damping parameter Rk (default: 0.0)

(6th line) nout, node_monit_1, nout_monit

Variable	Type	Description
nout	I	Unused
node_monit_1	I	Monitoring node number (global) or node group name
nout_monit	I	Monitoring-result output interval (default: 1)

Note: Information for the monitoring node specified on this line is output using the global node number as NID. Displacement is output to <dyna_disp_NID.txt> in the order step number, substep number, current time, NID, u₁, u₂, u₃. Velocity and acceleration are output in the same order to <dyna_velo_NID.txt> and <dyna_acce_NID.txt>, respectively. Nodal strain is output to <dyna_strain_NID.txt> in the order step number, substep number, current time, NID, e₁₁, e₂₂, e₃₃, e₁₂, e₂₃, e₁₃. Nodal stress is output to <dyna_stress_NID.txt> in the order step number, substep number, current time, NID, s₁₁, s₂₂, s₃₃, s₁₂, s₂₃, s₁₃, s_mises. If multiple monitoring nodes are specified using a node group, each of the above files is output separately for each node. In addition, when this output is specified, the kinetic energy, deformation energy, and total energy of the entire analysis model are output to <dyna_energy.txt> in the order step number, substep number, current time, kinetic energy, deformation energy, total energy.

Remarks

• In time-history dynamic analysis, multiple !STEP definitions can be used to switch boundary-condition and load groups for each step.
• For fixed-increment time control, it is recommended to use !STEP to explicitly specify SUBSTEPS and DTIME, ETIME on its second line. n_step and t_delta are used as defaults for a single-step analysis when !STEP is omitted, or for backward compatibility.
• When !STEP, INC_TYPE=AUTO is specified, automatic incrementation uses the initial time increment, step duration, minimum time increment, and maximum time increment specified on the second line of !STEP. Automatic-increment parameters can be specified with !AUTOINC_PARAM.

(7th line) iout_list(1), iout_list(2), iout_list(3), iout_list(4), iout_list(5), iout_list(6)

Variable	Type	Description
iout_list(1)	I	Displacement output setting (default: 0) 0: Do not output 1: Output
iout_list(2)	I	Velocity output setting (default: 0) 0: Do not output 1: Output
iout_list(3)	I	Acceleration output setting (default: 0) 0: Do not output 1: Output
iout_list(4)	I	Reaction-force output setting (default: 0) 0: Do not output 1: Output
iout_list(5)	I	Strain output setting (default: 0) 0: Do not output (element-based or node-based) 1: Output 2: Output (node-based) 3: Output (element-based)
iout_list(6)	I	Stress output setting (default: 0) 0: Do not output (element-based or node-based) 1: Output 2: Output (node-based) 3: Output (element-based)

Example

!DYNAMIC, TYPE=NONLINEAR
  1 , 1
  0.0, 1.0, 500, 1.0000e-5
  0.5, 0.25
  1, 1, 0.0, 0.0
  100, 55, 1
  0, 0, 0, 0, 0, 0

When idx_resp=2 (frequency-response analysis)

(3rd line) f_start, f_end, n_freq, f_disp

Variable	Type	Description
f_start	R	Lower frequency
f_end	R	Upper frequency
n_freq	I	Number of response calculation points
f_disp	R	Frequency at which displacement is measured

(4th line) t_start, t_end

Variable	Type	Description
t_start	R	Vibration start time in real time
t_end	R	Vibration end time in real time

(5th line) idx_mas, idx_dmp, ray_m ,ray_k

Variable	Type	Description
idx_mas	I	Mass-matrix type (fixed at 1 (lumped mass matrix))
idx_dmp	I	1: Rayleigh damping
ray_m	R	Rayleigh-damping parameter Rm (default: 0.0)
ray_k	R	Rayleigh-damping parameter Rk (default: 0.0)

(6th line) nout, vistype, nodeout

Variable	Type	Description
nout	I	Number of samples in the time domain
vistype	I	Visualization-data output setting (1: modal space, 2: physical space)
nodeout	I	Monitoring node ID in the frequency domain

(7th line) iout_list(1), iout_list(2), iout_list(3), iout_list(4), iout_list(5), iout_list(6)

Variable	Type	Description
iout_list(1)	I	Output control: displacement (1: output, 0: do not output)
iout_list(2)	I	Output control: velocity (1: output, 0: do not output)
iout_list(3)	I	Output control: acceleration (1: output, 0: do not output)
iout_list(4)	I	Ignored
iout_list(5)	I	Ignored
iout_list(6)	I	Ignored

Example

!DYNAMIC
  11 , 2
  14000, 16000, 20, 15000.0
  0.0, 6.6e-5
  1, 1, 0.0, 7.2E-7
  10, 2, 1
  1, 1, 1, 1, 1, 1