MBD Simulation on a Piston Assembly
Aim: The aim is to perform a MBD simulation on a Piston Assembly using Solidworks.
Introduction & Basic Theory:
Multi-Body Dynamics or MBD is the study of the movement of various parts in the assembly with each other. By performing MBD one can see the behaviour or path trached by the different parts present in the assembly. Thus using this method an engineer can visualize the motion and the behaviour of the complete assembly and take the steps further steps for manufacturing thus reducing the time nad cost.
A Piston assembly is the heart of any ICE. This assembly consists of a Crank, Connecting Rod, Gudgeon Pin and the Piston.The explosion that happens on the combustion chamber provides tha linear motion to the piston which in turn leads to the rotaion of the crank from which the output can be extracted.
In our case we are going to model the above mentioned parts in solidworks and we will provide the rotary motion to the crank to study the linear displacemnent of the piston.
The Motion Study in solidworks hepls us to provide the linar or rotay motion to a particular component of the assembly. By further adding the contact between different parts we can run the calculation and see the movement of different parts with respect too each other. Not only this we can also see the results for various parameters like displacent, forces, velocity n etc.
Procedure:
Using the dimmensions shown in the video cad models of each parts has been created the screen shots of the same can be seen below:
Piston:
Gudgeon Pin:
Connecting Rod:
End Cap:
Crank:
The assembly:
Also the cad files od each file and assembly had been attached below:
Now we can see the case wise sudy:
Case 1: Wrist/gudgeon pin with 0 mm offset with acrank roation of 2000rpm :
The animation of the same can be seen below:
Note that the animations had been played with a 0.1x reduction rate so that the movements can be visible.
this is done in all the three cases
The velocity graph of the piston can be seen below:
From the graph we can see that the displacement is near to about 100 mm.
Case 2:Wrist/gudgeon pin with 10 mm positive offset and the crank rotates in the clockwise direction at 2000 rpm
The animation of the same can be seen below:
The velocity diagram for this case is as shown below:
Case 3:Wrist/gudgeon pin with 10 mm negative offset and the crank rotates in the clockwise direction at 2000 rpm
The animation of the same can be seen below:
The velocity diagram for this case is as shown below:
From the graphs we can see that the displacement in all the three cases are almost to 100 mm. There is a minute change in the graphs which can be read in the excel sheets data.
Also we can see below the superimposition of the three graphs:
From the graph above, we can see thet the displacement in the 10 mm positive and negative is more or less same, but for the 0 mm offset the displacement is bit more than the other two. Thus the time taken to take the same displacement is more and the same is being represented in the graph. Thus the 0 mm offset graph travel time increses per cycle.