I am trying a suspension bridge in RM Bridge V8 and I model main cable by cable element, but when I calculator seflweight of suspension bridge then it error Node support in node of main cable and I modeling node support have value 1e+10 in CMX, CMY, CMZ, and deflection is very large, So, I hope everybody help me can fix error and linking cable elements into a unified whole is a soft wire structure.
if can, everybody can give me a file RM Bridge to refer, please.
I hope reply to every body about my problem.
Thank you so much and good luck.
If you're creating a full 3D model you might as well need to restrain the rotation DOF's for all cable elements at their begin and end (φx = φy = φz = 1E10)
We always indicate to use the latest version of our products, in RM Bridge CONNECT Edition you can find the Suspension bridge model simple example at File\Examples\Demo Examples & FAQ\Suspension Bridge with documentation and datasets.
Senior Technical Support Engineer, Bridge
MSc., Structural Analysis Specialist, Civil Engineer, RM Bridge Enterprise
Bentley Systems Inc.
Hi Marcos Beier.
I am very happy to your reply.
I already read the content of your comments, I model φx = φy = φz = 1E10 for Node support value of node main cable but The displacement of the main beam is very large and I model displacement in the X direction is 1E10 and I The displacement of the main beam is 900mm (main span 400m long). I found acceptable results.
I have a question, if I model displacement in the X direction is 1E10, Have main cable of suspension bridge worked it is reality a main cable in a suspension bridge?
I hope you read the content of my comments and reply my question.
Thank you very much.
Have a nice day and good job.
Hi again Dang,
We are also very happy to see that you could move FW with your project analysis with our guidance.
As in RM Bridge cables have only longitudinal stiffness they need to be constraint against rotation. Therefore, it's commonly accepted that the structural system might need all this boundary conditions.
Moreover, due to the highly statically indeterminate and also the nonlinearity of cable sagging it's ok to even include additional girder and main cable to be fixed horizontally. This additional constraint method allows for shape finding of the suspended cable as only very simple cases with an extremely reduced number of cables would converge without this horizontal restraints.
Hi again Marcos Beier.
I get your reply, I am very grateful for this.
I am currently modeling a suspension bridge with a span diagram of 125m-400m-125m.
And, I have referenced how to calculate tension of main cable and hanger cable as instructed in Demo of RM Bridge V8, and I obtained a deflection of 2.2m. I realize that the cable tension at the edge of the cable is negative (meaning that the cable is compressed), I want to ask you if I should adjust the cable hanger's internal force to reflect the working nature of the rope bridge?, Of course, here I adjust the internal force according to the displacement control.
I look forward to hearing from you.
Hello MarcosBeier .