xiaotie 发表于 2007-9-24 14:16:16

我用ADAMS2003模拟空气阻力，请指教

我用ADAMS2003模拟空气阻力，请指教

[ 本帖最后由 xiaotie 于 2007-9-26 10:23 编辑 ]

xiaotie 发表于 2007-9-24 14:19:28

!
!-------------------------- Default Units for Model ---------------------------!
!
!
defaults units&
   length = mm&
   angle = deg&
   force = newton&
   mass = kg&
   time = sec
!
defaults units&
   coordinate_system_type = cartesian&
   orientation_type = body313
!
!------------------------ Default Attributes for Model ------------------------!
!
!
defaults attributes&
   inheritance = bottom_up&
   icon_visibility = on&
   grid_visibility = off&
   size_of_icons = 50.0&
   spacing_for_grid = 1000.0
!
!------------------------------ Adams/View Model ------------------------------!
!
!
model create&
   model_name = model_1
!
view erase
!
!--------------------------------- Materials ----------------------------------!
!
!
material create&
   material_name = .model_1.steel&
   adams_id = 1&
   youngs_modulus = 2.07E+005&
   poissons_ratio = 0.29&
   density = 7.801E-006
!
!-------------------------------- Rigid Parts ---------------------------------!
!
! Create parts and their dependent markers and graphics
!
!----------------------------------- ground -----------------------------------!
!
!
! ****** Ground Part ******
!
defaults model&
   part_name = ground
!
defaults coordinate_system&
   default_coordinate_system = .model_1.ground
!
! ****** Markers for current part ******
!
marker create&
   marker_name = .model_1.ground.MARKER_3&
   adams_id = 3&
   location = 0.0, 0.0, 0.0&
   orientation = 0.0d, 0.0d, 0.0d
!
! ****** Floating Markers for current part ******
!
floating_marker create&
   floating_marker_name = .model_1.ground.FMARKER_4&
   adams_id = 4
!
part create rigid_body mass_properties&
   part_name = .model_1.ground&
   material_type = .model_1.steel
!
part attributes&
   part_name = .model_1.ground&
   name_visibility = off
!
!----------------------------------- PART_2 -----------------------------------!
!
!
defaults coordinate_system&
   default_coordinate_system = .model_1.ground
!
part create rigid_body name_and_position&
   part_name = .model_1.PART_2&
   adams_id = 2&
   location = 0.0, 0.0, 0.0&
   orientation = 0.0d, 0.0d, 0.0d
!
part create rigid_body initial_velocity&
   part_name = .model_1.PART_2&
   vx = 1.0E+004&
   vy = 1.0E+004&
   vz = 1.0E+004
!
defaults coordinate_system&
   default_coordinate_system = .model_1.PART_2
!
! ****** Markers for current part ******
!
marker create&
   marker_name = .model_1.PART_2.MARKER_1&
   adams_id = 1&
   location = 0.0, 0.0, 0.0&
   orientation = 0.0d, 0.0d, 0.0d
!
marker create&
   marker_name = .model_1.PART_2.cm&
   adams_id = 5&
   location = 0.0, 0.0, 0.0&
   orientation = 0.0d, 0.0d, 0.0d
!
marker create&
   marker_name = .model_1.PART_2.MARKER_2&
   adams_id = 2&
   location = 0.0, 0.0, 0.0&
   orientation = 0.0d, 0.0d, 0.0d
!
part create rigid_body mass_properties&
   part_name = .model_1.PART_2&
   material_type = .model_1.steel
!
! ****** Graphics for current part ******
!
geometry create shape ellipsoid&
   ellipsoid_name = .model_1.PART_2.ELLIPSOID_1&
   adams_id = 2&
   center_marker = .model_1.PART_2.MARKER_1&
   x_scale_factor = 1486.6068747318&
   y_scale_factor = 1486.6068747318&
   z_scale_factor = 1486.6068747318
!
part attributes&
   part_name = .model_1.PART_2&
   color = GREEN&
   name_visibility = off
!
!----------------------------------- Forces -----------------------------------!
!
!
force create direct force_vector&
   force_vector_name = .model_1.VFORCE_1&
   adams_id = 1&
   i_marker_name = .model_1.PART_2.MARKER_2&
   j_floating_marker_name = .model_1.ground.FMARKER_4&
   ref_marker_name = .model_1.ground.MARKER_3&
   x_force_function = ""&
   y_force_function = ""&
   z_force_function = ""
!
!------------------------------ Dynamic Graphics ------------------------------!
!
!
defaults coordinate_system&
   default_coordinate_system = .model_1.ground
!
geometry create shape force&
   force_name = .model_1.VFORCE_1_force_graphic_1&
   adams_id = 1&
   force_element_name = .model_1.VFORCE_1&
   applied_at_marker_name = .model_1.PART_2.MARKER_2
!
!---------------------------------- Accgrav -----------------------------------!
!
!
force create body gravitational&
   gravity_field_name = gravity&
   x_component_gravity = 0.0&
   y_component_gravity = -9806.65&
   z_component_gravity = 0.0
!
!----------------------------- Analysis settings ------------------------------!
!
!
!---------------------------- ADAMS/View Variables ----------------------------!
!
!
variable create&
   variable_name = .model_1.a&
   units = "no_units"&
   use_allowed_values = no&
   real_value = -3.854
!
!----------------------------- Simulation Scripts -----------------------------!
!
!
simulation script create&
   sim_script_name = .model_1.Last_Sim&
   commands =   &
            "simulation single_run transient type=auto_select end_time=5.0 number_of_steps=50 model_name=.model_1 initial_static=no"
!
!---------------------------- Function definitions ----------------------------!
!
!
force modify direct force_vector&
   force_vector_name = .model_1.VFORCE_1&
   x_force_function = ".model_1.a*VX(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)/1000"&
   y_force_function = ".model_1.a*VY(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)/1000"&
   z_force_function = ".model_1.a*VZ(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)/1000"
!
!--------------------------- Expression definitions ---------------------------!
!
!
defaults coordinate_system&
   default_coordinate_system = ground
!
geometry modify shape ellipsoid&
   ellipsoid_name = .model_1.PART_2.ELLIPSOID_1&
   x_scale_factor = (2 * 743.3034373659mm)&
   y_scale_factor = (2 * 743.3034373659mm)&
   z_scale_factor = (2 * 743.3034373659mm)
!
material modify&
   material_name = .model_1.steel&
   youngs_modulus = (2.07E+011(Newton/meter**2))&
   density = (7801.0(kg/meter**3))
!
geometry modify shape force&
   force_name = .model_1.VFORCE_1_force_graphic_1&
   applied_at_marker_name = (.model_1.VFORCE_1.i)
!
model display&
   model_name = model_1

xiaotie 发表于 2007-9-24 14:25:50

使用方法，打开记事本,将二楼数据粘贴,后缀*.CMD存盘,打开
ADAMS2003->IMPORT对话框,选择文件打开即可,注:ADAMS2003
不支持中文名文件,或者进入ADAMS2003后,用宏DEBUG亦可

xiaotie 发表于 2007-9-24 14:39:34

建模思路:
1:进入ADAMS,单位选MMKS
2:设置空气阻力系数A=3.854
3:建圆球
4:用三分量力,第一个选大地,第二选圆球,再圆球质心
5:修改三分量力分别
X:a*VX(MARKER_2,MARKER_3,MARKER_3,MARKER_3)/1000
Y:a*VY(MARKER_2,MARKER_3,MARKER_3,MARKER_3)/1000
Z:a*VZ(MARKER_2,MARKER_3,MARKER_3,MARKER_3)/1000
设置球初速,随意,我X,Y,Z,都为10000

xiaotie 发表于 2007-9-24 14:50:13

其中第五步,VX,VY,VZ分别测量X,Y,Z的速度,MARKER_3大地坐标,MARKER_2可选圆球质心,A为空气阻力系数,/1000是因为MMKS长度单位是MM,力单位N(KG*M/(S^2))如果觉得方向不对可乘(-1)即
X:a*VX(MARKER_2,MARKER_3,MARKER_3,MARKER_3)/1000*(-1)
Y:a*VY(MARKER_2,MARKER_3,MARKER_3,MARKER_3)/1000*(-1)
Z:a*VZ(MARKER_2,MARKER_3,MARKER_3,MARKER_3)/1000*(-1)

xiaotie 发表于 2007-9-24 14:53:37

以上,空气阻力=空气阻力系数*物体速度
方向与物体移动方向相反,
求各位高手告知还有别的公式吗

xiaotie 发表于 2007-9-26 10:12:14

再来一个：

xiaotie 发表于 2007-9-26 10:12:40

!
!-------------------------- Default Units for Model ---------------------------!
!
!
defaults units&
   length = mm&
   angle = deg&
   force = newton&
   mass = kg&
   time = sec
!
defaults units&
   coordinate_system_type = cartesian&
   orientation_type = body313
!
!------------------------ Default Attributes for Model ------------------------!
!
!
defaults attributes&
   inheritance = bottom_up&
   icon_visibility = on&
   grid_visibility = off&
   size_of_icons = 50.0&
   spacing_for_grid = 1000.0
!
!------------------------------ Adams/View Model ------------------------------!
!
!
model create&
   model_name = model_1
!
view erase
!
!--------------------------------- Materials ----------------------------------!
!
!
material create&
   material_name = .model_1.steel&
   adams_id = 1&
   youngs_modulus = 2.07E+005&
   poissons_ratio = 0.29&
   density = 7.801E-006
!
!-------------------------------- Rigid Parts ---------------------------------!
!
! Create parts and their dependent markers and graphics
!
!----------------------------------- ground -----------------------------------!
!
!
! ****** Ground Part ******
!
defaults model&
   part_name = ground
!
defaults coordinate_system&
   default_coordinate_system = .model_1.ground
!
! ****** Markers for current part ******
!
marker create&
   marker_name = .model_1.ground.MARKER_3&
   adams_id = 3&
   location = 0.0, 0.0, 0.0&
   orientation = 0.0d, 0.0d, 0.0d
!
! ****** Floating Markers for current part ******
!
floating_marker create&
   floating_marker_name = .model_1.ground.FMARKER_4&
   adams_id = 4
!
part create rigid_body mass_properties&
   part_name = .model_1.ground&
   material_type = .model_1.steel
!
part attributes&
   part_name = .model_1.ground&
   name_visibility = off
!
!----------------------------------- PART_2 -----------------------------------!
!
!
defaults coordinate_system&
   default_coordinate_system = .model_1.ground
!
part create rigid_body name_and_position&
   part_name = .model_1.PART_2&
   adams_id = 2&
   location = 0.0, 0.0, 0.0&
   orientation = 0.0d, 0.0d, 0.0d
!
part create rigid_body initial_velocity&
   part_name = .model_1.PART_2&
   vx = 1.0E+004&
   vy = 1.0E+004&
   vz = 1.0E+004
!
defaults coordinate_system&
   default_coordinate_system = .model_1.PART_2
!
! ****** Markers for current part ******
!
marker create&
   marker_name = .model_1.PART_2.MARKER_1&
   adams_id = 1&
   location = 0.0, 0.0, 0.0&
   orientation = 0.0d, 0.0d, 0.0d
!
marker create&
   marker_name = .model_1.PART_2.cm&
   adams_id = 5&
   location = 0.0, 0.0, 0.0&
   orientation = 0.0d, 0.0d, 0.0d
!
marker create&
   marker_name = .model_1.PART_2.MARKER_2&
   adams_id = 2&
   location = 0.0, 0.0, 0.0&
   orientation = 0.0d, 0.0d, 0.0d
!
part create rigid_body mass_properties&
   part_name = .model_1.PART_2&
   material_type = .model_1.steel
!
! ****** Graphics for current part ******
!
geometry create shape ellipsoid&
   ellipsoid_name = .model_1.PART_2.ELLIPSOID_1&
   adams_id = 2&
   center_marker = .model_1.PART_2.MARKER_1&
   x_scale_factor = 1486.6068747318&
   y_scale_factor = 1486.6068747318&
   z_scale_factor = 1486.6068747318
!
part attributes&
   part_name = .model_1.PART_2&
   color = GREEN&
   name_visibility = off
!
!----------------------------------- Forces -----------------------------------!
!
!
force create direct force_vector&
   force_vector_name = .model_1.VFORCE_1&
   adams_id = 1&
   i_marker_name = .model_1.PART_2.MARKER_2&
   j_floating_marker_name = .model_1.ground.FMARKER_4&
   ref_marker_name = .model_1.ground.MARKER_3&
   x_force_function = ""&
   y_force_function = ""&
   z_force_function = ""
!
!------------------------------ Dynamic Graphics ------------------------------!
!
!
defaults coordinate_system&
   default_coordinate_system = .model_1.ground
!
geometry create shape force&
   force_name = .model_1.VFORCE_1_force_graphic_1&
   adams_id = 1&
   force_element_name = .model_1.VFORCE_1&
   applied_at_marker_name = .model_1.PART_2.MARKER_2
!
!---------------------------------- Accgrav -----------------------------------!
!
!
force create body gravitational&
   gravity_field_name = gravity&
   x_component_gravity = 0.0&
   y_component_gravity = -9806.65&
   z_component_gravity = 0.0
!
!----------------------------- Analysis settings ------------------------------!
!
!
!---------------------------------- Measures ----------------------------------!
!
!
measure create object&
   measure_name = .model_1.VFORCE_1_MEA_1&
   from_first = yes&
   object = .model_1.VFORCE_1&
   characteristic = element_force&
   component = x_component
!
data_element attributes&
   data_element_name = .model_1.VFORCE_1_MEA_1&
   color = WHITE
!
measure create object&
   measure_name = .model_1.VFORCE_1_MEA_2&
   from_first = yes&
   object = .model_1.VFORCE_1&
   characteristic = element_force&
   component = y_component
!
data_element attributes&
   data_element_name = .model_1.VFORCE_1_MEA_2&
   color = WHITE
!
measure create object&
   measure_name = .model_1.VFORCE_1_MEA_3&
   from_first = yes&
   object = .model_1.VFORCE_1&
   characteristic = element_force&
   component = z_component
!
data_element attributes&
   data_element_name = .model_1.VFORCE_1_MEA_3&
   color = WHITE
!
measure create object&
   measure_name = .model_1.PART_2_MEA_1&
   from_first = yes&
   object = .model_1.PART_2&
   characteristic = cm_velocity&
   component = x_component
!
data_element attributes&
   data_element_name = .model_1.PART_2_MEA_1&
   color = WHITE
!
measure create object&
   measure_name = .model_1.PART_2_MEA_2&
   from_first = yes&
   object = .model_1.PART_2&
   characteristic = cm_velocity&
   component = y_component
!
data_element attributes&
   data_element_name = .model_1.PART_2_MEA_2&
   color = WHITE
!
measure create object&
   measure_name = .model_1.PART_2_MEA_3&
   from_first = yes&
   object = .model_1.PART_2&
   characteristic = cm_velocity&
   component = z_component
!
data_element attributes&
   data_element_name = .model_1.PART_2_MEA_3&
   color = WHITE
!
!---------------------------- ADAMS/View Variables ----------------------------!
!
!
variable create&
   variable_name = .model_1.a&
   units = "no_units"&
   use_allowed_values = no&
   real_value = -3.854
!
!----------------------------- Simulation Scripts -----------------------------!
!
!
simulation script create&
   sim_script_name = .model_1.Last_Sim&
   commands =   &
            "simulation single_run transient type=auto_select end_time=5.0 number_of_steps=50 model_name=.model_1 initial_static=no"
!
!---------------------------- Function definitions ----------------------------!
!
!
force modify direct force_vector&
   force_vector_name = .model_1.VFORCE_1&
   x_force_function = ".model_1.a*(VX(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)/1000)**2*if(VX(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)-0:-1,0,1)"&
   y_force_function = ".model_1.a*(Vy(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)/1000)**2*if(Vy(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)-0:-1,0,1)"&
   z_force_function = ".model_1.a*(Vz(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)/1000)**2*if(Vz(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)-0:-1,0,1)"
!
!--------------------------- Expression definitions ---------------------------!
!
!
defaults coordinate_system&
   default_coordinate_system = ground
!
material modify&
   material_name = .model_1.steel&
   youngs_modulus = (2.07E+011(Newton/meter**2))&
   density = (7801.0(kg/meter**3))
!
geometry modify shape ellipsoid&
   ellipsoid_name = .model_1.PART_2.ELLIPSOID_1&
   x_scale_factor = (2 * 743.3034373659mm)&
   y_scale_factor = (2 * 743.3034373659mm)&
   z_scale_factor = (2 * 743.3034373659mm)
!
geometry modify shape force&
   force_name = .model_1.VFORCE_1_force_graphic_1&
   applied_at_marker_name = (.model_1.VFORCE_1.i)
!
model display&
   model_name = model_1

xiaotie 发表于 2007-9-26 10:21:48

以上使用方法与以前一样，不同的是公式
空气阻力=空气阻力系数*物体速度的平方
方向与物体移动方向相反,
所以以X为VX(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)求物体速度
VX(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)/1000将单位化成米
(VX(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)/1000)**2物体速度的平方
model_1.a空气阻力系数
if(VX(.model_1.PART_2.MARKER_2,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3,.model_1.ground.MARKER_3)-0:-1,0,1)"控制方向因为速度的平方为正数,必须控制方向因为方向与物体移动方向相反

xiaotie 发表于 2007-9-26 10:22:27

求各位高手告知还有别的公式吗

xiaotie 发表于 2007-9-27 14:19:37

求各位高手告知还有别的公式吗

xiaotie 发表于 2007-9-30 14:42:13

求各位高手告知还有别的公式吗

xiaotie 发表于 2007-9-30 16:34:42

求各位高手告知还有别的公式吗

xiaotie 发表于 2007-10-5 09:03:01

求各位高手告知还有别的公式吗
.

setem1949 发表于 2007-10-5 15:23:03

在ADAMS/CAR下面，对车身模拟空气阻力有更简单的办法

bauer 发表于 2007-10-5 15:34:21

原帖由 setem1949 于 2007-10-5 15:23 发表 http://www.simwe.com/forum/images/common/back.gif
在ADAMS/CAR下面，对车身模拟空气阻力有更简单的办法
Easy5里面也有相应的空气动力学模块

xiaotie 发表于 2007-10-6 10:22:42

原帖由 setem1949 于 2007-10-5 15:23 发表 http://www.simwe.com/forum/images/common/back.gif
在ADAMS/CAR下面，对车身模拟空气阻力有更简单的办法
可我用的不是车,建模怎么办

1990chs 发表于 2013-9-3 21:52:39

xiaotie 发表于 2007-9-26 10:21 static/image/common/back.gif
以上使用方法与以前一样，不同的是公式
空气阻力=空气阻力系数*物体速度的平方
方向与物体移动方向相反,


感觉好像不对，最近我也在想办法添加空气阻力，我觉着应该是VX*VM，因为用VX的话，三个分量的平方和不等于VM^2
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