In SolidWorks, use the FLEX feature.
Use the model you already made, cut off the curve and bend it to your needs.
Then add the flat part again. Combine those two parts to one part. Done.
Hope this helps.
i dont have solid works im using autocad
Well, then you would have to model the positiv form of what you want to remove.
Then make a pattern of your positiv and remove (subtract) from your model the positiv forms. --> Boolean operation.