Problem set 2 -week 3 challenge : Anti-Characteristics

CALCULATE THE FOLLOWING PARAMETERS BASED ON THE GIVEN DATA PROVIDED BELOW AND ENTER THE CALCULATED DATA IN A SPREAD SHEET :-

Given data,

1. Following parameters to be calculated are,

• Front end deflection under load.
• Rear end deflection under load.
• Pitch angle.
• Pitch gradient.

The front end deflection under load is 0.63 in.

The rear end deflection under load is 0.487 in.

The pitch angle is 0.65 degrees.

The pitch gradient is 1.3 deg/g.

2. USING THE INSTANT CENTER LOCATION CALCULATE THE FOLLOWING PARAMETERS :-

• Front anti lift angle.
• Rear anti squat angle.
• Front swing arm angle for 100% anti lift.
• Rear swing arm angle for 100% anti squat.
• Front anti lift %.
• Rear anti squat %.

The front anti lift angle is 3.45 degrees.

The rear anti squat angle is 6.047 degrees.

The front and rear swing arm angle for 100% anti lift and anti squat is 9.84 degrees.

Front anti lift % is 0%.

Rear anti squat % is 60.8%.

3. TO ELIMINATE THE PITCH ANGLE (THEORITICALLY), KEEP THE REAR SWING ARM HEIGHT FIXED AT 16 INCHES FROM THE CONTACT PATCH. CALCULATE THE FOLLOWING :-

• Front anti lift % and rear anti squat % for zero pitch angle.
• Front end deflection under load accounting for new anti characteristics.
• Rear end deflection under load accounting for new anti characteristics.
• Pitch angle, accounting for new anti characteristics. (Verify that it is zero).

In order to eliminate the pitch angle, the rear instant centre horizontal distance from the contact patch is decreased to 11 inches from the default value of 42.5 inches.

Once the Rear IC Horizontal distance is reduced the pitch angle becomes 0.016 degrees.

The front anti lift % remains at 0 %.

The rear anti squat % increases to 223.82 %.

The front end deflection remains the same 0.63 in.

The rear end deflection decreases to -0.6 in.

All calculations are performed in a spreadsheet and the link to the spreadsheet is given below.

https://docs.google.com/spreadsheets/d/1415K8lcUeq8vtCSv-k5iPA0bWEKV30HHarIVfWfi2uY/edit?usp=sharing

CONCLUSION :-

The anti-characteristics of a suspension system are calculated based on the given data on a spreadsheet.