This section describes how to build events in the full vehicle model with Altair Driver. The new event user interface is supported only for models with Altair Driver. The interface exports .adf and .xml files and submits them to MotionSolve. Files can be edited or updated in the Event Editor. Eighteen event types are supported.
This section describes all of the full vehicle events currently supported with Altair Driver. It also describes all of
the events and their parameters.
A Constant radius event simulates a vehicle driving in a circular path, typically with increasing speed. The event predicts
the vehicles roll and understeer characteristics with increasing lateral acceleration.
A Double lane change event drives the vehicle through a lane change and a return to lane maneuver, attempting to follow
the centerline of the defined lane.
A Swept Sine event simulates a vehicle driving at a constant speed with a sinusoidal steering input of constant magnitude
but increasing frequency applied.
A J-turn event simulates a vehicle response to a large steer in one direction, a dwell time to allow the vehicle to react,
and a large steer in the opposite direction, with an additional reaction time.
A Throttle-off cornering event simulates the dynamics of a vehicle driving a constant radius turn at steady state and
the reaction of the vehicle due to a sudden removal of the drive torque while cornering.
A Throttle-off turn-in event simulates a vehicle driving straight at constant speed, turning on to a constant radius,
then after reaching steady state the throttle is closed and the steering is ramped to tighten the turn.
The Road Course Drive event can be used to simulate full vehicle models on the required road profile. The event also provides
a means to study vehicle performance in the areas of durability/fatigue and ride comfort.
The Stability Analysis event can be used to simulate two-wheeler models on various road surfaces to evaluate the weave
and wobble modes of the vehicle. A user-defined road property file determines the road input.
A Slalom event drives the vehicle in a straight, followed by a sequence of turns around cones in alternate directions.
The vehicle velocity is held constant.
Driver can be loaded using the Model Wizard of MDLLIB when the Full Vehicle with Driver option is chosen. Driver has
some special requirements to interface with the vehicle model. These requirements are resolved automatically if the
vehicle model is built using the Full vehicle with advanced driver option in the Model Wizard in MDLLIB.
This section describes all of the full vehicle events currently supported with Altair Driver. It also describes all of
the events and their parameters.
The n-Post event is useful in the correlation process to
ensure the virtual model produces valid results. Using the road profiles from the proving
ground as an input to the simulation and defining the necessary outputs for loads or
accelerations, the fidelity of the virtual model can be established by comparing results from
measurement and simulation. The correlated model can then be used to perform durability and
fatigue tests. The post processing of the results is possible using the Altair product,
HyperLife. The steps involved in the process are described in
the following tutorial.
At present, the following outputs can be generated using the results from the
simulation:
Damage and Life contours
Damage and Rainflow matrix
Range pair damage
Pseudo damage
The first two result pairs (the damage and life contours and damage and rainflow
matrix) can be calculated only for flexible components.
Apart from the predefined
outputs, other outputs that are of interest can also be created within MotionView.
Life Contour
The contour plot for Life shows the
available life for the given fatigue analysis. It represents the number of cycles until the
part will experience failure due to fatigue.
Damage Contour
The contour plot of the damage is
calculated for a given design life. The damage is the design life divided by the available
life. When the damage values calculated are greater than 1, it is an indication of failure
before the design life is reached.
The Rainflow Matrix and the Damage Matrix may be used in
the case of variable amplitude fatigue analysis. In a variable amplitude loading history,
equivalent constant amplitude cycles must be identified. The fatigue damage for all the
cycles in the loading history are summed to obtain the damage for the entire loading
history.