Studying Vehicle Dynamics parameters for Passenger bus

KATARI LOKESH
KATARI LOKESH New Altair Community Member
edited March 2021 in Community Q&A

Hello Experts,

Hope you are doing good.

I am looking to analyze the following parameters of suspension and steering assembly in passenger bus. Can we get these parameters in MV. Can you please  briefly let me know how to do it?

 

  1. Ackermann Error
  2. Bump steer
  3. Brake Steer
  4. On Centre steering
  5. Off Centre steering
  6. Steering disturbance
  7. Straight line stability
  8. Primary ride
  9. Secondary ride

 Thank you for your time

Regards

Lokesh

Tagged:

Answers

  • AnanthK
    AnanthK
    Altair Employee
    edited March 2021

    Lokesh - This is a complex subject and a loaded question. It looks like you have clubbed suspension design factors from a system-level test (1-3), vehicle-level tests (4 & 5), and entire groups of chassis attributes (6-9) in your list. That being said, MV/MS is fully capable of doing all of these. Please study the vehicle modeling section in the online help, and come back with more specific questions.  

  • KATARI LOKESH
    KATARI LOKESH New Altair Community Member
    edited March 2021

    Hello Ananth,

    thanks for your message. I have gone through the online help and understood how to calculate some parameters. But I left with some few parameters. Can you please help me how to calculate the

    1. Steering disturbance

    2. Straight line stability.

    3. On Centre steering

     

    It would be really helpful

     

    thanks 

    lokesh

  • AnanthK
    AnanthK
    Altair Employee
    edited March 2021

    Hi Lokesh - There isn't a single calculation for any of these. They are characterizations done at the system and vehicle-level, which results in multiple attributes being calculated. On-center, as well as steering disturbance (drift/pull, skate etc) are much more complex to model than off-center handling due to the sensitivity to small slip-angle tire force & moment characteristics. There is detailed physical testing required to support a modeling effort for this. You need the tire properties at very small slip angles as a minimum. Also, you need a detailed model of the steering system which includes the hydraulic or electric assist characteristics as well. This means several steps of validation required to produce meaningful results at the vehicle-level. It can take many months to generate the data and develop a process. For this reason, OEMs often utilize physical testing and subjective evaluation to characterize and tune these attributes. 

Categories