In railway or highway design projects, structure engineers always receive decided alignment from the project manager. Highway or Railway alignment usually changes slightly because of many external factors while working on a project. Sometimes, slightly changed alignment can have potential critical issues to construction or other project steps, serviceability, and even a legal issue. For example, a transition curve is related to drivability and driving safety. If so, structural engineers must recognize and consider that minor change. Let's look into how structure engineers change alignment during their projects.
Traditionally, structural engineers must use CAD when starting a global analysis project. Divide the entire alignment and consider the span length, bearing locations, etc, to create nodes for checking analysis results. After the CAD work process, the engineers export that CAD file in a DXF format to MIDAS CIVIL NX. For convenience, people use Lisp or Autocad VBA; however, human error issues remain. The engineers needed to conduct the above cumbersome workflows repeatedly.
MIDAS CIVIL NX users might need help to create models when their models have a complex alignment, such as curved bridges, cable bridges, or ramps. Alignment Generator will create complex continuous alignment based on plug-in input values. The user can select straight, arc, clothoid, and cubic parabolas for line shape, radius, and length and set up segment distances, including assigned sections and material on each part of the alignment.
The plug-in uses internal Spiral Calculating functions as follows:
The Clothoid:
Cubic Parabola:
This part will explain the operating steps and each component in detail.
1. Open MIDAS CIVIL NX → Connect API → Open Plug-in Marketplace → Run Alignment Generator Plugin
Alignment Generator Plugin Screenshot
2. When users operate the Alignment Generator plug-in, they can add this plug-in to the users’ bookmark(1). The user can read plug-in information(2) and start by clicking the Run(3) button.
Alignment Generator Plugin
3. A new pop-up window will appear as this image. The user can add(1), select Line types(2), length, start, and end radius(3). In the segment setting, the user will input the distance between created nodes(=length of elements). The users can set up each segment’s Structure group, Material, and Section ID(4). The bottom of the graph(5) changes and previews the users’ inputs.
You can check more of these details in the download file.