central difference

[tangzhen]

hello,i have some problems with central difference in the anslysismodel,and i want to know how the central difference method works and the date exchanged in the project.thank you very much.

[fmk]

yes and no. it works BUT it does not at the first step determine the state at t-Dt. if an eqrthquake analysis this will not matter as the start of the record is typically just a bunch of 0's and result at 0-dT would be 0. if it matters
do 1 step with another integrator.