Practica De Dmp

Practica No 3

Four bar velocity

Topics convered
In this tutorial, you will learn how to: 1. Create a marker 2. Change angle units 3. Add motion 4. Create center of mass angular velocitymeasurements

Four bar velocity problem

In the four-bar linkage shown, control link OA has a counterclockwise angular velocity omega = 5 rad/s during a short interval of motion. When the link CBpasses the vertical position shown, point A has coordinates x = -60 mm and y = 80 mm. By means of vector algebra, determine the angular velocity of AB and BC. This problem asks for the rotational velocityof segment BC when it is in the pictured position given a constant and known rotational velocity for segment OA. We will use ADAMS to create a model with the given conditions and collect the dataneeded.
Problem 5/84 from J. L. Meriam and L. G. Kraige, Engineering Mechanics: Volume 2, Dynamics 3rd edition. John Wiley & Sons, Inc. Copyright © 1992, by John Wiley & Sons, Inc. This material is usedby permission of John Wiley & Sons, Inc.

What You Should Accomplish
If you are successful, you should end up with a ADAMS model that illustrates angular velocity of the links in a four barmechanism.

Creating the Model
a. Start ADAMS. B .Create a new model. (Model Name = fourbar, Units = mmks, Gravity = none) c. Modify the spacing of the Working Grid (X = 10mm, Y= 10mm) d. Click Unitsfrom Settings menu e. Select Radian from Angle pull down menu f. Click OK

Create a Marker
a. Open Coordinate Window b. Select Marker tool from Rigid Body tool stack c. Create a marker at each of thefollowing coordinates: O (0, 0, 0); A (-60, 80, 0); B (180, 180, 0); C (180, 0, 0)

Create Links and Joints
a. Create links OA, AB, and BC, using the markers as end points. b . Make revolutejoints between two links at points A and B, and between link and ground at O and C.

Add Motion
a. Select Rotational Motion from motion tool stack b. Enter (5 rad) in Speed text field c. Select...