train loading generator error in arrival time.

see attachment. There is an error in arrival time.

In Midas, Loading function is correct. The arrival time is not correct.   Loading function is nothing to do with arrival time because starting time in loading function diagram is t=0.

Based on your calculations, I can say that you are assuming the load to arrive with a "loading slope" on node 1.  But in fact, the load would be like an impact on node 1 and at the same time, it would have an upward slope for node 2.  Hence, the arrival times will ALWAYS be the same for the first 2 nodes.

Hope this clarifies the doubt.  Do let us know if further assistance would be required.