MBD Simulation on a Piston Assembly

Aim -1)To model and assemble internal combustion piston assembly

2)To carry out motion anlaysis using solidworks.

3)To study effect of wristpin offset on linear displacement of piston.

Introduction -

Piston assembly is as example of slider crank mechanism.In slider crank mechnism crank rotates as slider moves to and fro. this mechanism is used to obtain rotational output from linear repeatition.By process of combustion piston moves to and fro. and crank rotates. this provide rotational mechanical energy at output from combustion energy at input.

Procedure -

1) 3d modelling as per dimensions.

2)assembly by proper mates

3)providing motor at crank with 2000 rpm

4)carry out motion analysis and modify piston for wristpin offset and repeat analysis

5)plot linear displacement vs time for piston for all cases.

Piston assembly -

plot for zero offset-

plot for negative offset-

plot for positive offset-

superimposed plot-

conclusion -

From above plot it can be observed that wristpin offset decreases linear displacement of piston.But for zero offset when piston at tdc connecting rod becomes staight this exerts high loads on connecting rod and causes loss of power due to resistance to crank motion thus it is benificial to provide some offset to avoid above scenario.