Curved bridge with Steel Composite Wizard

Question:

I had created a 3 span curved girder model using the wizard and wanted to modify the pier skew. I saved my wizard file and started a new model. I was able to revise the skew, but it tells me it cannot create the "lanes" and that there is an error encountered in influence surface. What am I missing? In my none skewed model the lanes are generated just fine.

I have another question - I am reviewing the composite design excel reports and my short term and long term section properties are the same. How do I get MIDAS to use the 3n?

Thanks.



Answer:Dear User,

The issue seems to be with the geometry of the curve,

The closely spaced nodes and the undulations are why the surface lanes are not defined right.



For the lanes to be defined right, under "Section" tab in the wizard, Angle type should be "Skew" in the "Bracing information. As the option "Perpendicular" is chosen, the bracings would be perpendicular to each girder but the piers are skewed. Hence the nodes and elements were improperly created, i.e closely spaced at the bracing location.



When you choose the "Skew" in Angle Type, the Angle Cell gets disabled and the program uses skew angle defined in the Layout Tab. And, if the skew angle varies among the support, the skew angle for the transverse deck elements are interpolated.

Also, to get long-term properties right, Kindly Check on the "Multiple Modulus of Elasticity" and put the value for "3n" in the "Es/Ec" for creep and shrinkage as in the image below:

Creation date: 10/31/2017 5:35 AM ()      Updated: 10/31/2017 3:08 PM ()
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