Multi Body Dynamics (MBD)

A multibody dynamic (MBD) system is one that consists of solid bodies, or links, that are connected to each other by joints that restrict their relative motion. The study of MBD is the analysis of how mechanical systems move under the influence of forces, also known as forwarding dynamics. A study of the inverse problem, i.e. what forces are necessary to make the mechanical system move in a specific manner is known as inverse dynamics.

Motion analysis is important because product design frequently requires an understanding of how multiple moving parts interact with each other and their environment. From automobiles and aircraft to washing machines and assembly lines - moving parts generate loads that are often difficult to predict. Complex mechanical assemblies present design challenges that require a dynamic system-level analysis to be met.

Vehicle MBD

Acceleration:

Straight Line Events 

1.  Acceleration.

Inputs

1. Forward Velocity.
2. Road Data File.
3. Longitudinal Acceleration.

Output

1. Anti Squat.
2. Longitudinal Load Transfer.
3. Anti Lift.

Counter Measure

1. Side View Instant Center.
2. Spring & Damper Stiffness Tuning.

Step Steer:

Steering  Events 

1. Step Steer.

Inputs

1. Forward Velocity.
2. Road Data File.
3. Steering I/P angle.

Output

1. Lateral Acceleration.
2. Slip Angle.
3. Yaw Rate.
4. Steering Wheel Angle.

Counter Measure

1. Anti Roll Bar Tuning.
2. Damper Tuning.
3. Bushing Stiffness Tuning.

Constant Radius Cornering (CRC):

Cornering  Events 

1. Constant Radius Cornering (CRC)

Inputs

1. Forward Velocity.
2. Road Data File.

Output

1. Lateral Acceleration.
2. Slip Angle.
3. Load Transfer.

Counter Measure

1. Anti Roll Bar Tuning.
2. Damper Tuning.
3. Bushing Stiffness Tuning.

Subsystem MBD:

Static Loads Analysis for Durability Calculation:

Working conditions executed on assembly

1. Vertical Bump (3.5 g, 2.5g).
2. Braking.
3. Cornering.
4. Lateral Impact.
5. Longitudinal Impact.

Output

1. Force & Moment at each joint for durability calculation

Kinematics & Compliance (K&C):

The following analyses performed for K & C

1. Parallel Wheel Travel.
2. Opposite Wheel Travel.
3. Steering Analysis.
4. Static Load Analysis.

Output 

1. Camber, Toe, Caster, Kingpin Inclination, % Ackerman &Roll Stiffness.

Counter Measures:

1. Hardpoint Optimization.
2. Bushing, Spring & Damper properties Tuning.

Modeling

Modeling

1. Macpherson Strut Suspension.
2. Double Wishbone Suspension.
3. Rack Pinion Steering.
4. Leaf Spring.
5. Anti Roll Bar.
6. Truck Suspension