We've been asked by a client to integrate "Japanese Half-sine" spirals into our design...is the "Japanese Sine" option the same spiral? Or are these different? I cannot locate any documentation on spiral types integrated into SS4...also, for some reason, Power InRoads SS4 only offers Clothoid so we've been forced to switch over to Power Rail Track SS4.
Thanks for the help!
Yes, the rail products are going to offer the different rail type spiral definitions whereas InRoads will only supply the road/transportation option (clothoid). From discussions in the past, I believe the COSINE transition spiral is the same as the half-sine transition spiral. When assigning the spiral transition type, you will want to assign the transition as the Cosine.
This is not directly mentioned in the link below, but it does provide some illustration and definitions/equations of the transitions.
http://communities.bentley.com/products/rail_design/f/5921/t/65919
For more information about the Road and Site design tools, visit the Road and Site design WIKI at: http://communities.bentley.com/products/road___site_design/w/road_and_site_design__wiki
Is there any documentation available from Bentley that verifies the equations/spirals used in SS4? I need to assure my client that they are getting what they want...the only way I can do that right now is to display the same spiral/curve/spiral in Civil 3D (which has the Japanese Half-sine spiral) and compare the two. We have many curves in our alignment and this could be a tedious process that I prefer not to get into...why do you think the Cosine is the the same as the Japanese Half-sine? My mathematical understanding is that they are different...I've found documentation on the academic side that says the Cosine spiral is an "approximation" of the Japanese Half-sine. I need something concrete to take to my client...
Thanks for your help! -Chris
Japanese Sine Spiral which is renamed as Half Cosine spiral in the OpenRail Designer uses the following formula. Which as far as I can see is the same as the formula used in Civil 3D. We will also add all the formulas used in the spiral definitions to help document and communities, soon.
Can we have an official document from Bentley illustrating and mentioning the equations of the different spiral curves used in the software. I have a similar problem as faced by Chris. Official documents will be needed for convincing the client and getting approvals.
Regards
Malay
Dear Chris,
I hope that you would have already found out some concrete information regarding the equations of the curves, sufficient to convince client. Can you please share the documents/ information with me, for I am struggling with the same problem as you. It will be extremely kind of you to share the information and I will be deeply obliged.
mail: malayagar999@gmail.com