lab1 intro to adams and postprocessor

7/29/2019 Lab1 Intro to Adams and Postprocessor

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Welcome To Adams!

Adams is an infinitely complex program that allows you to dynamically simulate many different types of

mechanical systems and subsystems. Adams is able to accurately predict the behavior of real world

systems before they are physically manufactured. Adams View is a relatively simple program with

infinitely complex capabilities

Task 1:

Get to know the tools:

1.) Open up Adams View: Faculty and Department Apps > Msc.Software > MD Adams 2011 > AView> Adams-View

2.) Select Create a new model from the radio buttons. Name the model Four_Bar_Linkage (it isimportant to not use spaces as this will be saved as the file name). Gravity should be set to Earth

normal (-Global Y) and the units should be set to MMKS. And click OK

3.) The pull down menus are a handy way of accessing all of the tools you will need but the majorityof them are also located in the Main tool box (see figure 1) The tool bar at the bottom of the

main window will give a description of each tool that is highlighted but I have included quickdescriptions which can be used as a reference. The information area contains useful settings

when you are creating geometry and when the select tool is engaged it contains viewing

controls. If the tool box is not displayed it can be turned on through the drop down menu

View>ToolBox and Toolbars and then check mark the main tool box option.

Figure 1

Select

Rigid Bodies*

Measures*

Undo/Redo*

Joints*

Simulation controls

Colors*

Motion Drivers*

Animation

Position and Alignment*

Forces*

Plotting

Information Area

*Right click for more options


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4.) Proceed to right click on the tool box items that allow you for more selection and pay attentionto the bottom tool bar in the main window for a description of each icon, note how things like

the joints are similar to the kinetic constraints in catia as well as how the Rigid bodies are just

simplified elements to make quick designs. Later on you will be shown how to import complex

3d models from other pieces of software.

5.) To change the settings for the workspace in the main window they can be found underSettings>Working Grid in the dropdown menus at the top of the main window. For this example

they can remain unchanged but be sure to investigate the options available within the working

grid settings.


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6.) Press F4 to bring up the coordinate window, this window displays the coordinates of the cursor7.) Lets start by creating a link; this is usually the default icon under the rigid body section of the

main toolbox. To make sure, right click on the rigid bodies icon and select the icon in the top

left portion of the pop up that has appeared.

8.) Click on the end where you want the link and then click where you want the other end of thelink. While creating the link, pay attention to the options that are available in the information

area of the main tool box as these settings can be locked in place if you wanted to make links of

equal width, length or depth.

9.) Create a link from (0,0) to (50,200)10.)Create a link from (50,200) to (450,300)11.)Create a link from (450,300) to (400,0)12.)

Now that we have 3 links, (in the four bar mechanism the fourth bar is considered to bebetween (0,0) and (400,0) and representative of a stationary object or ground) we must create

the joints in order to allow for movement.

13.)Right click on the joint icon in the main tool box and select the top left icon (revolute joint) payattention once again to the options in the information area of the main tool box for this lab the

default values are acceptable. The information bar at the bottom will give you information as to


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how the revolute joint is created by default you select the first body, then the second body, then

the location of the joint.

14.)Create the first revolute joint by clicking the first link and then clicking anywhere in thebackground (the background represents the ground which is what you want the first link to

revolve with respect to) then select the location at point (0,0)

15.)Create the second revolute joint by selecting the first link, then the second link then the locationof (50,200)

16.)Create the third revolute joint by selecting the second link, then the third link and then thelocation of (450,300)

17.)Create the final revolute joint by selecting the third link, then the background and then thelocation of (400,0) by now it should look like :

18.)As we are about to simulate the mechanism we can now check our model in the bottom right ofthe main window you will see an icon with an I in it right click this icon and then click the

checkmark, this is how you check for degrees of freedom with in a simulation. You can close the

open window

19.)Now to add motion to our simulation, Right click on the Motion drivers icon in the main tool boxand select the top left icon Rotational Joint Motion. This applies a rotational motion to a

cylindrical or revolute joint. Note the information area in the main toolbox, the speed text box

is based off of your units, in our case it is degrees/ second. This can be checked under the

Settings>Units option of the dropdown menus in the main window and is considered to be angle

over time in terms of units. For now leave this as a default of 30. And select the joint at (0,0).This will now display two rotational arrows at (0,0) the smaller one representing the joint and

the larger one representing the rotational motion.


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20.)Click on the simulation controls button and change the end time option to duration in theinformation area of the main tool box. Also change the steps option to step size and leave the

default numbers and hit the play button.

21.)From here you can play with the duration and the step size to lengthen the simulation or obtainfiner results. When you would like to make changes you could click on the rewind button which

will reset everything to the initial positions. If you wish greater control of the animation it can be

found in animation controls in the review dropdown menu or the animation icon in the main

tool box.

22.)Now click on the plotting icon in the main toolbox. You can also use the F8 key to get you there.This is the main plotting area. We will cover this further in the next example, but for now look at

the bottom pane, you will have options to add different curves to the plots try plottingPart2.Marker2 angular velocity in the z axis verses Part3.Marker4 angular velocity in the z axis,

select your options and then click add curves. You might also want to try translational

displacement for those two points along the x and y-axis. (You can already see why its important

to rename your parts)


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Task 2, Post Processor:

Cam Assembly: Valve.cmd

1.) Start a new database in Adams (under the file menu) it will prompt you to save your previousmodel

2.) Ifyou havent saved the previous example you can now. By default Adams will save files as abinary with all of the information, open toolboxes and other changes, the other format is a cmd

file which just stores the model basic information and nothing from the post processor. You

open/save a bin file, import/export a cmd file. In the options for starting a new database select

import a file, change your working directory (Start in) to where you have saved your valve.cmd


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file and click ok

3.) Double click on the file to read text box and it will bring up a browse window, select valve.cmd

and select open and click ok. You can also right click and then select brows out of the options


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that appear. Select open and then click OK

4.) Right click on the black space in the middle of the model, this will bring up a view menu. (As long

as you arent clicking on any of the geometry. Remember the key shortcuts, as they will make it

easier to create models in the future.(Lower case r,t,z for example) use them to investigate the

model, and view it from different angles.


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5.) If you right click on any of the geometry you will get different options, try it now. You will notice

that all of the parts are named part and then a number. This is a default for Adams and as you

have seen from the previous example having those names makes it hard to discover the purpose


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in the post processor.

6.) Point to Part:PART_ and then select rename from the list that appears. Leave the .valve. As thisis the name of the model and change the rest after the second. Make sure to rename all of the

parts (no spaces)

7.) The value of renaming can also be seen by other information sources, right click on the I in thebottom of the main window and then select the top right icon (Model topology by constraints)

notice how renaming parts is useful. You can also rename joints if you wish. You can right click

on the I again and select the bottom right icon as well (Model topology by parts)


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8.) Lets run a simulation select the simulation icon, and set the settings to have an end time of 2and 100 steps. Hit play. When the simulation is complete hit the rewind button.

9.) Select the simulate menu at the top of the main window and then select Interactive controls.This will pop up a new window and in the bottom left you will see an icon which shows a film

strip moving into a folder, this allows you to save the simulation into the database for use in the

post processor (this information is not saved when you export to a .cmd file) this is useful when

testing different variations of a variable for example. Save this run as First_Run

10.)Now select the plot icon from the main tool bar. (Or press f8) and you should see the postprocessor in the lower section you will see a source drop down option box, make sure that thatmeasures is selected. Measures can be created on parts joints and forces and are created by

right clicking on the respective object and selected from the menu that appears

11.)Select the Force_in_Spring measure and add the curve to the graph12.)Press F8 or the icon in the top right (looking of two gears meshing) this will take you back to the

simulation window.


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13.)Right click on the spring and point to the spring in the menu that appears (this is where you canset up a measure as well as modify the spring) select Modify and change the spring rate to

200lbf/foot.

14.)Simulate the mechanism again and Save it as Second_Run15.)Return to the post processor (F8)16.)If your source is set to measures you will now see First_Run and Second_Run in the box under

simulation. This is why it is important to save the simulations as it allows you to compare

differences in variables and their effects.

In class work:

Model for translational weight on a horizontal spring:

Example 3.156 Engineering Mechanics, Dynamics 6th Ed.

lab1 intro to adams and postprocessor

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