topic Re: Moving loading outside the structure in Robot Structural Analysis Forum

Moving loading outside the structure

rbaraldi — Mon, 16 Sep 2024 11:31:52 GMT

Hi All,

I am modelling a skew rail deck and because I was having a different results than the expected I did a simulation with single-point loading moving through the structure and what I noticed was that I got reactions and result even with the load outside the structure.

Is there any explanation for that ? and what I can do to avoid that ?

Many thanks!

Re: Moving loading outside the structure

Rafacascudo — Mon, 16 Sep 2024 15:36:47 GMT

On the moving load dialog window , click on the parameters button and pay attention specially to the tolerance field (click on help button to have a full explanation about it).

Also pay attention to "application plane" on main window . Use selection to select the bars you want to be loaded only.

I selected the bars beneath the route line and set a huge tolerance so only concentrated loads would be applied to my selected bars.

Read all the moving load help section . Many good advices

Re: Moving loading outside the structure

rbaraldi — Wed, 18 Sep 2024 15:00:26 GMT

Hi Rafa,

Many thanks for the advice and info. Based on what I can see, the polyline is not the best approach.

The approach for the long route is the best one to run a moving load longer than the span or are there other options for that? I am asking that because when I consider the route the points between the span of the moving load stop when the first force comes to the end.

Re: Moving loading outside the structure

Rafacascudo — Thu, 19 Sep 2024 10:42:19 GMT

Normally, I set the polyline to make the 1st load of my vehicle be positioned on the " edge" of the structure,already over the 1st bar/panel.

Re: Moving loading outside the structure

rbaraldi — Thu, 19 Sep 2024 13:21:14 GMT

But what happen if your span is 20m and your moving loading is a sequence of point loads at XX m and the total is 30m?
What I notice in robot is when the first point load came to the end the moving load stop. that why I have been created the polyline outside my model.

Re: Moving loading outside the structure

Rafacascudo — Thu, 19 Sep 2024 15:15:16 GMT

There is no problem on creating a polyline larger than the bridge

on your vehicle the load set at X=0 will be positioned at the start of the polyline , so set the polyline to acomodate the entire vehicle before it enters the bridge

Re: Moving loading outside the structure

rbaraldi — Fri, 20 Sep 2024 08:13:28 GMT

Many Thanks for the info !!

Obrigado!

Re: Moving loading outside the structure

c.saouridis — Sun, 13 Oct 2024 09:43:31 GMT

Thanks to all, we had the same problem with route extending outside the bridge and we have solved it by following the instructions. It seems that the software does not recognize a load when it is found outside the bridge deck (on the ground) and the way to overcome this is to give a huge tolerance in the Parameters window.