Simulation on four bar mechanism
If a number of bodies(usually rigid bodies) are assembled in such a way that the motion of one causes constrained and predictable motion to others is called a mechanism.A mechanism transmits and modifies a motion.
There are various kinds of mechanisms involved to perform a particular kind of work or to complete an objective.Out of which Four bar mechanism is also one , this consists of four linkages having constrained by few kinds of motion to perfom a required task.
Types of four bar mechanisms ,
- Plane Quadrilateral Linkage : This has 4 revolute joints .
- Slider crank linkage : This joint has 3 revolute joint and a prismatic joint.
- Double slider : This has two revolute joints and two prismatic joints.
(http://en.wikipedia.org/wiki/Four-bar_linkage)
From the model given the following steps are to be followed to have a simple four bar mechanism in motion view and motion solve ,
step 1 : Create points A,B,C,E,F with cordinates (921,580,1124),(918,580,1114), (915,580,1104),(878,580,1108),(878,580,1118).These hard points can also be according to the users requirements based on the length of the linkages.
Step 2 : Use macros and create points along the vector in between CE and EF.
step 3 : Create the bodies as reqired for better graphical understanding and visualization,by properly assigning the parent body ,origin and the direction for each graphic.
Step 5 : Now create revolute joints between the bodies of intrest and the ground body.
step 6 : Add motion at the revolute joint and then check for the no.of redundant constraints.If the redundant constraints exists then reduce them to zero.For this we just need to make some corrections in the motion provided to the joints.
Step 7 : Now create an output to measure the torque.For that we have to define expression.
Name of the expression with argue requirements : Motion ({id string},{jflag},{component or magnitude},{reference marker})
step 8 : Fill the expression with the requirement of the torques and then run the model and view the animaton and graph.
The video of the output is as shown ,
https://drive.google.com/open?id=1dOKTJVbDMfQ_GliUMvNeYji6gJe8ZyfB
Hence the variation of the output torque or the force can be clearly onserved from the plot obtained.