请教base motion的用法

winken_zu

base motion按照如下方法用，是否表示对同一个基础进行三向加速度同时加载？如果不对，运用什么关键字可以实现对同一基础进行三向不同加速度载荷加载？谢谢
*MODAL DYNAMIC, CONTINUE = NO
0.01      ,3.0
*Modal Damping
1, 15, 0.02  
*base motion, dof=1, amplitude=wave, scale=9800
*base motion, dof=2, amplitude=wave1, scale=9800
*base motion, dof=3, amplitude=wave2, scale=9800

winken_zu

那位高手指点一下吧，急用

winken_zu

难道没有人用这个关键字进行求解？

stone08

1st STEP
*FREQUENCY, EIGENSOLVER = LANCZOS, NORMALIZATION = MASS
,1.0       ,500.    ,,,
*BOUNDARY,OP=NEW,BASE NAME=ACCEL_pt1_x
node #,1,1,0.0
*BOUNDARY,OP=NEW,BASE NAME=ACCEL_pt1_y
node #,2,2,0.0

** node # is the node for base excitation input
** Accel_pt1 will be referred to the subsequent step
.......
......

2nd step
*MODAL DAMPING,MODAL=DIRECT,DEFINITION=FREQUENCY RANGE
xxxxx
xxxx
*BASE MOTION, TYPE = ACCELERATION, LOAD CASE =  1, AMPLITUDE = accel_pt1curve_x,DOF=1,BASE NAME=ACCEL_pt1_x
*BASE MOTION, TYPE = ACCELERATION, LOAD CASE =  1, AMPLITUDE = accel_pt1curve_y,DOF=1,BASE NAME=ACCEL_pt1_y


** accel_pt1curve is the amplitude definition for your base excitation

wang_guo860

*motion怎么用的
  指定平动速度？

hunanyangdong

我想施加单点频率的harmonic base motion，使用如下语句，计算的结果确不对，请问Amplitude曲线中的频率的单位是cycle/s还是rad/s啊？
*Amplitude, name=AMP-1
          1.,      0.03099,          19.,      0.03099,          20.,     13.85929,          52.,     2.256129
        900.,     22.56129,        2000.,     4.59661,        2001.,      3.099
**
** BOUNDARY CONDITIONS
**
** Name: Disp-BC-1 Type: Symmetry/Antisymmetry/Encastre
*Boundary
SUPP, ZASYMM
** ----------------------------------------------------------------
**
** STEP: Step-1
**
*Step, name=Step-1, perturbation
*Frequency, eigensolver=Lanczos, acoustic coupling=on, normalization=displacement, number interval=1, bias=1.
10, , , , ,
**
** OUTPUT REQUESTS
**
*Restart, write, frequency=0
**
** FIELD OUTPUT: F-Output-1
**
*Output, field, variable=PRESELECT, mode list
1, 2, 3,
*End Step
** ----------------------------------------------------------------
**
** STEP: Step-2
**
*Step, name=Step-2, perturbation
*Steady State Dynamics
1., 10000., 20, 1.
*Modal Damping, structural
1, 10, 0.1
*BASE MOTION,DOF=2,AMPLITUDE=Amp-1,SCALE=1
*NODE PRINT,FREQUENCY=1
PU,PTU

Chenniuniu

stone08 发表于 2011-7-8 01:23
1st STEP
*FREQUENCY, EIGENSOLVER = LANCZOS, NORMALIZATION = MASS
,1.0       ,500.    ,,,

您这个我看明白了点，但是有个小小的疑问：您这个应该是加的x向余弦加速度，幅值是在AMPLITUDE里设置，问题是LOAD CASE=1已经表示为余弦，那么在AMPLITUDE里只要设置幅值大小就可以了吧，那应该选择哪个类型如何设置幅值呢