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09-01-05 1(14)
Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
Laboration 1: Introduction to ADAMS modeling a piston
pump
The main purpose of this exercise in ADAMS is to improve the ability and understanding for how
ADAMS works and to illustrate the importance in analyzing and interpreting the results. This is
very important to emphasize that even if you are using very powerful programs you need to have
full control of the modeling as well as the analysis.
In this exercise we will study the behavior of a piston pump consisting of a piston, a flywheel and a
crankhandle, see figure 1. This pump will be used to pump liquids. The piston is gliding in a
cylinder (not shown in figure 1) and is sucking liquid from a house when the piston is moving out
from the cylinder. When the piston is moving into the cylinder it is pumping this liquid into another
house. The model you are building up in this exercise is shown in Figure 1 below
Figure 1. Piston Pump Isometric view
PUMP DATA
Wheel radius = 0.03 m Handle mass = 0.3 kg
Wheel thickness = 0.01 m Handle mass inertia:Ixx= 0.00001 kgm2-
,Iyy=Izz=0.0001 kgm2
Wheel density = 7800 kg/m3
Piston length=0.06 m
Handle length = 0.1 m Piston diameter = 0.04 m
Handle width = 0.015 m Piston massa=0.2 kg
Handle depth=0.01 m Piston mass inertia:Ixx 0.0001 kgm Iyy=Izz=0.0002 kgm
Table 1. Pump data
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KTH 2Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
The following tasks should be completed
1. The wheel radius should be parameterizedNote that all markers on the crank and the piston should be parameterized.
2. The flywheel is driven counter clockwise with a speed of 100 rpm.
3. Plot the piston position as a function of time (0-2 sec). Also plot the velocity as a function oftime.
4. Plot the resulting normal force on the piston (t= 0- 2 sec)
5. Plot the pump driving torque. Why is it varying?
6. Add a push or pull force on the piston, which is varying between + 1000N and -1000 Ndepending on in which direction the piston is moving.
7. Make a DESIGN_STUDY where the wheel radius can vary between 0.02 and 0.04m. Whatis the relation between radius and the driving torque?
Report
This exercise can be either be approved directly by the assistant at the scheduled event or sent as a
short report. If it is sent as a report it should contain plots from the tasks 4, 5 and 7 and answer the
questions in these tasks. The report should be sent in electronic form to [email protected],
[email protected] or [email protected]. This means that you continuously should select and save plot
curves as picture files during this exercise.
To start this exercise you need to do the following setup:
Starting Up ADAMS/View
From the ADAMS Product Menu, select ADAMS/View OK
Creating a Database from the Welcome dialog box
Create a new model Model Name: pistonpump (or: kolvpump ) OK
Setting up your work environment
Units
Setting Units Set the units: M, KG, N, SEC, DEG, H
Working Grid
F4 ( or: View Coordinate Window) , to let Coordinate Window ON
Settings Working Grid
Size: X=0.2, Y=0.1; Spacing = 0.005 (without units)
Show Working Grid = on; Set Location Global Origin OK
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KTH 3Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
Icons
Settings Icons New Size = 0.01; Visibility = On OK
Gravity
Check: Settings Gravity = ON, Y=-9.80665 OK
Building Piston Pump Model
Hints :
Start with creating points using theMain Toolbox, added to ground (Dont attach)in the
locations shown in Table 1.
Table 1. Points Coordinate Location
X Y Z
POINT_1 0.0 0.0 0.0
POINT_2 0.03 0.0 0.0
POINT_3 0.10 0.0 0.0
POINT_4 0.13 0.0 0.0
POINT_5 0.18 0.0 0.0
The Wheel
Create the Wheel part and its geometry (cylinder) using the design points
Note that you have to modify the orientation of the working grid and that then you have to
rename the part to wheel. The reorientation is done by utilizing the Working grid. :
SettingsWorking gridSet OrientationGlobal YZ
An additional hint could be to use the ISOMETRIC view for better visual control.
Once the Wheel part is created the working grid should be restored to its original setting i.e.
Global XY.
Place the cursor over wheel geometry Part: WheelModify Set up: Mass Properties
defined by =Geometry and Density, Density = 7800 Apply Show calculated inertia
OKThe Handle
Create the handle in a similar way as you did for the wheel, but use the link geometry.
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KTH 4Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
Modify the mass and inertia properties by using the modify option :Mass Properties defined
by =User Input Change to: Mass = 0.3, Ixx = 0.00001, Iyy = 0.0001 Izz = 0.0001 OK
The Piston
Create the piston as a cylinder with a start position at POINT_3 and dimensions as shown inTable 1.
Modify the mass and inertia properties in the same way as for the handle.
Defining the Joints
We need to define three revolute joints and one translational joint. Place these joints at the
locations defined by the design points.
We will use the following construction options:
1 Location, Normal To Grid (revolute joint between wheel and ground) use POINT_1
2 Bod-1 Loc, Normal To Grid (revolute joint between wheel and handle and revolute joint
between handle and piston) use POINT_2 and POINT_4
2 Bod-1 Loc, Pick Feature (translational joint between piston and cylinder (ground)) use
POINT_4..
Now it is time to save your model
File Save Database As File Name =pistonpump1.bin OK
Your model should now look like this in the FRONT view:
Figure 2.Piston pump front view
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KTH 5Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
Testing Your First Prototype
Adding motion on the Wheel
Main Tool boxMotion Rotational Joint Motion
Set up: Speed=600
Pick onjoint icon in the center of the Wheel
Simulating and Animating the Motion of the First Prototype
Main Tool box Simulation Set up: Kinematic, End Time=2.0, Steps=100 Pick
on Simulation Start tool
Main Tool box Animation Pick on Forward tool
Plot the Displacement of the Piston
Main Tool box Plotting, ADAMS Post Processor (PPT) will start!
Source: Objects Filter = body Object = +piston Characteristics =CM Position
Component = X Add Curves
On the SIDE TREEVIEW, Expand PAGE 1, select Plot 1.
In the Title text box, type:Piston Displacement
A title will appear in the SIDE TREEVIEW
Select A title Change the Font Size to 16
Select Vertical Axis Axis: vaxis
Labels=Length (meter), Font Size=14
Select: Numbers Font Size=12
Select Horizontal Axis Axis: haxis
Select Labels Label= Time (sec) , Font Size=14
Select Numbers Font Size=12
Your plot should look like figure 3 Piston Displacement
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KTH 6Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
Figure 3.Piston Displacement
Plot the Velocity of the Piston
On Main tool bar, Pick Create a new page
Your plot should look like figure 4 Piston Velocity:
Figure 4.Piston Velocity
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KTH 7Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
Plot the Normal Force of the Piston
Source: Objects Filter = constraint Object = +JOINT_3* Characteristics
=Element_Force Component = Y Add Curves
* Joint between Handle and Piston
Figure 5.Normal Force of Piston
Plot the Pump Driving Torque
Source: Objects Filter = constraint Object = +MOTION_1 Characteristics
=Element_Torque Component = Z Add Curves
Figure 6. Pump Driving Torque
File Close Plot Window
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KTH 8Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
Adding a Push and pull force on the Piston
Create a design point to connect the force to at the top of the piston (0.16,0.0,0.0)
(POINT_6)
Create a single component force, 2 bodies: Piston and ground (use POINT_5)
Create the force function. This function should give +- 1000 N depending on the moving
direction of the piston.
Hint: Use the SIGN and VX (or VR) function in the FUNCTION BUILDER.
SIGN(a1,a2) returns a1 dependent on the sign of a2.
VX(To,From;Along,Ref.Frame) returns the velocity in X-direction between two
markers in a given reference frame.
Simulating and Animating the Motion of the Prototype
Simulate the motion of the pump for 2.0 sec 100 steps.
Plot the Pull and Push Force of Piston
Your plot should look like the one below:
Figure 7.Pull and Push Force of Piston
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KTH 9Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
Plot the Pump Driving Torque
Your plot should look like the one below:
Figure 8.Pump Driving Torque
Refining Your Design
Creating Design Variables
Place the cursor over POINT_2 Point: POINT_2 Modify The Table Editor will
appear.
Select The Loc_X for POINT_2
Click in the input box at the top of the Table Editor Parameterize Create Design
Variable Real
The Design Variable is given the default name .pistonpump.DV_1 :
Change the name to .pistonpump.Radius by using the menu Edit Rename
Select The Loc_X for POINT_3
Click in the input box at the top of the Table Editor Parameterize Reference Design
Variable Radius OK
At the top of the Table Editor, change to (.pistonpump.Radius+0.07) Select The Loc_X for POINT_4
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KTH 10Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
Click in the input box at the top of the Table Editor Parameterize Reference Design
Variable Radius OK
At the top of the Table Editor, change to (.pistonpump.Radius+0.1) Select The Loc_X for POINT_5
Click in the input box at the top of the Table Editor Parameterize Reference Design
Variable Radius OK
At the top of the Table Editor, change to (.pistonpump.Radius+0.15) OK Select The Loc_X for POINT_6
Click in the input box at the top of the Table Editor Parameterize Reference Design
Variable Radius OK
At the top of the Table Editor, change to (.pistonpump.Radius+0.13) OK Build Design Variable Modify Radius OK
Set up: Standard Value = 0.03, Units= length , Value Range by =Absolute Min and Max
Values, Min. Value= 0.02, Max. Value= 0.04 OK
Reviewing Design Variables
Tools Table Editor Select the Variables at the bottom of the table Editor
Filters Select: Delta Type=ON, Units=ON OK
Parameterizing other Geometries of your model
1. Parameterizing the Wheel
Place the cursor over WheelCylinder: CYLINDER_1Modify
Place the cursor in the Radius text box Parameterize Reference Design Variable
Radius OK
OK
2. Parameterizing the handle.cm Marker
Place the cursor over handle.cm MarkerMarker: cmModify
Change to Location = (.pistonpump.Radius+0.05), 0.0, 0.0 OK
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KTH 12Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
Running a Design Study
SimulateDesign Evaluation
Set up: Design Study=ON, Measure=ON, Maximum of = .pistonpump.MOTION_MEA_1,Design Variable .pistonpump.Radius, Default levels = 5
Settings: Display Chart Objective=ON, Chart design variables = ON, Save stripchart
curves=ON, Show tabular report = ON OK
Adjust the windows to see more Start
ADAMS displays Piston displacement plot (cm_MEA_1), Piston Velocity plot (cm_MEA_2),
Driving Torque plot (MOTION_MEA_1), Radius vs. Trial plot, MOTION_MEA_1 vs.
Radius plot, and a design study report.
Close the information window and the Design Evaluation box
Transfer the strip charts to full plot
Place the cursor over cm_MEA_1 chart Plot: scht1 Transfer to full plot
Your transferred plot should look like the one below:
Figure 9.Piston Displacements vs. Time
You can edit the plot, if you like.
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KTH 13Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
File Close Plot Window
In the same way, you can transfer the other charts, as shown next:
Figure 10.Piston Velocities vs. Time
Figure 11.Pump Driving Torque vs. Time
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KTH 14Institutionen fr MaskinkonstruktionSystem och komponentdesignKjell Andersson
Figure 12.Pump Driving Torque vs. Radius of the Wheel
Note: The title and the labels of the axis have been edited
Figure 13.Radius of the Wheel vs. Trial
Note: The title and the labels of the axis have been edited
All Done! To Save Your Work: Use a COMMAND FILE (.cmd). Note that your plots will NOT be
saved only the model.
Note that you first have to save the plots needed for the report.
Show your simulation plots to the lab assistant to get approved on the Lab before you exit
ADAMS.
File Export ADAMS/View command file, Exit ADAMS