ADAMS - Problem 1 - Front view Geometry

Steps:

-First sla suspension is opened

-then original hard points table are compared with the given had points

-then parallel wheel travel analysis is performed

-then x variable is chosen which is wheel travel

-then y axis variable was chosen which is fvsa length

-then curve was plotted

-it showed that Fvsa length is 2914 mm

-then another y axis variable was chosen to plot the fvsa angle

-it showed that the angle was 5.21 degrees

 Adams convention:

Calculation:

-Adams uses hypotentous as its swing arm while we the horizotal distance,inorder to convert between the two we will use the front view angle:

Triangle ABC:

Fvsa length(horizontal)(AB)=fvsl hypotenous(Ac)*cos(fvsa angle)=2914*cos(5.21)=2902mm

Camber gradient=arctan(1/fvsl(horizontal)(AB))= arctan(1/2902)=0.0197deg/mm

h=fvsa length*sin(fvsa)=2914*sin(5.21)=264.6 mm

H=wheel center height+h=300+264.6=564.6 mm

TRAINGLE CDE:

theta=arctan(H/fvsa length horizontal)=arctan(564.6/2902)=11 deg

Roll center height=0.5*tackwidth*tan(11)=0.5*1600*tan(11)=155.5 mm

Comparing to adams:

Adams roll center height is 154.3 (0.8% difference)

Adams camber gradient is 0.0196 deg/mm (0.5% difference)

The results show that there is minimal deviation compared to adams

Geometry sketch:

From the sketch: (As studied in theory)

Roll center height:138.843 mm

Fvsa length:3025 mm

Fvsa angle:9.846 deg

-Tuning the hard pints:

Tuned camber gradient curve:

New camber gradient of 0.022deg/mm

Tuned roll center location:

New roll center location 145 mm

 Why lower front roll center?

-Lower roll center can be used to combat and reduce understeer in front heavy vehicle, as it will delay the loss of grip on that axle as it will reduce load transfer on that axle compared to the rear, so the rear axle will reach its limit first.

Files:

https://drive.google.com/drive/folders/1Feh2tiYDMtp8CRX_G4_R4KWGdbn6JcA1?usp=sharing