Applying Linear Pattern to inside curved surface

ProblemSolver

I'm absolutely stumped, I am trying to apply a Linear Pattern to the underside of an 3 Arch Viaduct Bridge: https://cad.onshape.com/documents/ab039effdefc81af5b5cd9c7/w/622fae194371f421edaffbdb/e/809c1cfa691fd4df8292060d , but I cannot get it to work, can anyone with experience in this area please help me overcome this issue?

mahir

I don't know what the intended pattern is supposed to look like, but here's one example of how it could be done. FYI I had to clean up your Main Section sketch to make it symmetrical and fully dimensioned. Otherwise, the patterns wouldn't merge properly.

https://cad.onshape.com/documents/4142e516888d1483a4e05127/w/7e390dd28118bfa6f4d91bfa/e/7cb9ece468ec420c76cdbe02

mahir

I don't know what the intended pattern is supposed to look like, but here's one example of how it could be done. FYI I had to clean up your Main Section sketch to make it symmetrical and fully dimensioned. Otherwise, the patterns wouldn't merge properly.

https://cad.onshape.com/documents/4142e516888d1483a4e05127/w/7e390dd28118bfa6f4d91bfa/e/7cb9ece468ec420c76cdbe02

ProblemSolver

Thank you Mahir, this change that you have done achieves exactly what I was after. Thank you so much, I am over the moon with appreciation. Exactly what was the issue, so that I can avoid this problem from here on?

mahir

No problem. If you look at your version of the Main Section sketch, it was missing controlling dimensions and relations. So I dimensioned one arch radius and set the other equal to it. I also positioned all the lines with coincident/horizontal constraints and added dimensions for the separation between arches. All of those dimensions were just slightly off by a fraction of a millimeter, which made patterning difficult since the tile bodies weren't making contact with the arches.Once that was fixed, it was just a matter of adding a circular pattern to tile one arch and then a linear pattern to tile the other two arches.

ProblemSolver

Many thanks again Mahir for your explanation of the problems that you fixed for me. 
I have been removing some of the highlighted constraints when the sketch title appears in red. 
From here on I will delete a constraint one at a time until it repairs the issue (until the Red text changes back to black), then I will undo the deletion and move onto to next constraint (stepping through systematically) until I find the conflicting constraint.