MBD Simulation on a Piston Assembly

Note: please consider my request i.e., my excel was expired and I can't compile all the three graphs but I have added my comments on them please take my comments for valuation.

AIM:

MBD simulation on the piston assembly with a different offset of a pin.

Sl.No	Wrist Pin Offset `	Crank Speed (Rpm)
1	"0" mm	2000
2	10 mm Positive	2000
3	10 mm Negative	2000

Why piston offset?

Having offset pin relieves the stress that is caused in the rod when it reaches top or bottom dead centre. For the rod does not have to slam the piston up and then back down. The rod travels more in an arc.

In general, offset is made towards major thrust face (piston face which his in contact with the cylinder when the time of combustion) in order to reduce piston slap.

PROCEDURE:

1. Designing 3d solid body of piston head, connecting rod, gudgeon pin, crank, N cap.

2. Assemble with proper constraints.

3. First, make wrist pin free from the offset and plot the graph of linear displacement of the piston head

repeat the with same with +ve 10mm offset and -ve 10mm offset.

4. Spread the plot sheet in to excel and compile the 3 plots.

RESULTS AND DISCUSSIONS:

1. Plots are smooth and uniform in 3 cases but with the offset stroke is reduced

2. Advantage, Offsetting might prevent the mechanism from locking in a toggle position since the force on the connecting rod will never be in line with it. This can make the engine self-starting.