tutorial question

Creation date: 10/24/2017 8:14 PM    Updated: 6/18/2023 3:47 AM
Question:
I’m working on the following tutorial for the Steel Composite Tub-Girder Bridge Design as shown below in Figure 1. http://en.midasuser.com/training/tutorial_read.asp?idx=493&pg=2&so=&sort=&bid=6&nCat=&nCat2=127&bType=&totCount=31
Figure 1: MIDAS tutorial
1. The pier support at the center appears to the incorrect shape. How do I revise this to be similar to the tutorial? Was this revised when I used the tapered section? See Figure 2:
2. Under Analysis -> Construction Stage Analysis Control Data, the following error is at the bottom of the page “construction stage analysis control data data can be added/modified/deleted in base stage only”. See Figure 3. I’m not sure what I’m doing wrong here for following the tutorial on page 35 of the pdf.
Figure 2: Pier Supports
Figure 3: construction stage analysis control data (will not allow me to hit ok)
Answer:
1. Please Change section offset to Center-Top then program would show you that beam element line is placed along the top of the section.


2. You can define construction stage analysis control data in base stage as shown below.


Question2:
 when I run my model it is giving me errors for the deflection. I opened the completed model and looked at the supports/boundary conditions and do not seem to see my error. I’m not sure what I’m doing wrong here

Answer2:
At stage 2, as there is no link between girder and coping, the girder cannot transfer the load to the column. Therefore, girders have to resist on the load by themselves but there is no boundary for the girders. You should activate the links at stage 2.



To activate the links at stage 2, you should include the node which connects the link.


Question3:
I have a similar question for the boundary condition error with this model. The error reads “Boundary Condition has not been defined.” I think the reason that I’m getting this error is that I moved the supports from the top of the deck to the bottom of the bearing locations. Therefore, in my model I added a rigid link from the old support location (say node 3) to bottom of the girder (say node 1433) and then an elastic link to the bottom of the bearing (say node 1459).
I think the reason I’m getting this error is that there is no support locations now in stage 1. Isn’t the boundary conditions set in the “base” construction stage? I can’t seem to add in these links for stage 1 manual as the nodes do not show up at the bottom of the girders. Also, I can’t activate them in the construction stage 1 (under define C.S.).
Answer3:
1. If you want to activate the supports, you should activate the relevant nodes which has the support conditions defined within a structural group and not only the relevant boundary group
otherwise, the program cannot recognize the supports as there are nodes to apply the support to.

2. There are further problems within the model file. The supports are not connected to the structure so the supports are not providing any support to anything.
Files