transient analysis

What's the best open source FE code for nonlinear transient analysis of truss structures (preferably with Python interface)?

i have to do transient analysis of ball beraing. but i could not get an appropiate tutorial to perform transient analysis using full method or mode superposition method since i cannot apply reduced method. please guide me how to apply the load step and what options to use.

hello friend

my self raj .

in the beam and shell element " thermal OR temparature vs time" transient analysis possible ? 

   i have four story building model , if apply a temprature vs time history at second floor then  can i find out the each floor tempreture at each time steps ? due to thats also find out the strees and moment or  force at each node due to elongation of beam sheel element due to temparature incraese.