Dynamic analysis For Railway Bridge

Hello Everyone,
for my master thesis, I need to do dynamic analysis of a railway bridge. With the help of the template provided by Sofistik. I got to manage to get the first results and my acceleration is way too big (15 m/sec2) and honestly doesn’t make any sense. Now to make the acceleration smaller I tried to enlarge the del parameter by 0.80 and that is how I got a smaller acceleration(m/sec2). Now my question can I mix the two methods (Newmark-method and Modal Analysis) to have even a smaller acceleration if not what other choices do I have to do? Because I tried So many things and this is the only way to get an acceleration smaller than 3.5 m/sec2.

PS: The Eigenfrenquency and the loads are correct in my Modell I double-check them many times and with hand Calculation also



As far as I know, the methods shown are used to solve the terminating condition of the equations of motion. So you have to select one of them and they can not be mixed.
Since I don’t know anything about your project/system I can only give you a few tips that may help you.

  1. Check the support conditions → If using springs: Is the stiffness appropriate?
  2. Check the stiffness of the bridge components
  3. Try to vary the integration time steps
  4. Try to understand the program behaviour on a simple problem. Perhaps you have a referenc project that can be analysed.
  5. Consult your professor/advisor

Also, I assume you’ve already seen the DYNA examples in the TEDDY?

TEDDY > File > Examples > DYNA > english > tsi > …

Best regards
Frederik Höller
Your SOFiSTiK Support Team