Suspension Analysis using MSC Adams

The analysis of the suspension characteristics of the DICV NR-XIII was carried out on MSC Adams to verify the expected behaviour of the car according to the design. The accuracy of this analysis was validated using Lotus Shark.

Process flow of analysis on MSC Adams:

Obtain Template Download of template from MSC Knowledge baseObtaining database: fsae_2008r1_MDR3.cdb

Opening Database Addition of obtained database to current session

Front Suspension The front suspension assembly is loaded from the databaseDisabling of anti roll bar aspect of assembly

Hard points Setting of originAdjusting of hardpoints from the table view

Setting Suspension parameters

Wheel base: 1600 mm Sprung mass: 270 kgWheel mass: 10 kgBrake ratio: 65%Drive Ratio: 100%

Setting toe and camber Camber: -1 degreesToe: 0 degrees

The above process is repeated for the rear suspension and the graphs are obtained.

Front Suspension:

SpringPlot Spring characteristic curveSet preload

Tire DataEnter tire stiffness and unloaded radiusAlternatively load property file

Parallel Wheel Travel Analysis

Setting up analysis parametersBump: 27 mm Rebound: 27mm

Animation Verification of expected behaviour

Post processingLoading of required analysis log filesCreating plots

PlotsLoading of Plot configuratin file from shared directoryInterpretation of obtained graphs

Model Created (MSC Adams):

Isometric Front View

Front View

Hard points Table:

Suspension Parameters:

Animation of Simulation:

Analysis Parameters:

Graphs Obtained:

Camber vs Wheel travel:

Toe angle vs Wheel Travel:

Caster vs Wheel Travel:

Validation (Lotus Shark):

Model:

Graphs:

Camber vs Wheel Travel:

Toe Angle vs Wheel Travel:

Caster vs Wheel Travel:

Rear Suspension

Model Created (MSC Adams):

Front isometric view

Front view

Hardpoints Table:

Suspension Parameters:

Animation of Simulation:

Analysis Parameters:

Graphs Obtained:

Camber vs Wheel Travel:

Toe angle vs Wheel Travel:

Validation (Lotus Shark):

Model:

Graphs:

Camber vs Wheel travel:

Toe Angle vs Wheel Travel:

Comment on Graphs obtained:

Parallel wheel travel analysis was performed on the front and rear suspension for three values of brake ratios : 55 60 65. As expected, brake ratio did not affect the variation of the suspension characteristics, witnessed by the overlapping graphs obtained.

The suspension behaves as expected and meets the expectations set during the design stage. Thus the design can be promoted to the manufacturing stage.

Conclusion:

Parallel wheel travel analysis was done for the proposed design on MSC Adams using the bump and rebound values for which the suspension is designed. The accuracy of this analysis was validated by performing the same on Lotus Shark. The above designs for the front and rear suspensions meet the design criteria and can be incorporated into the final vehicle.

Credits:

Dayasagar

Jim Harris

Rakshith

Prajwal MP