The best replacement for catia is solidworks.

The best alternatives to catia are rated as following:
★★★★★  solidworks
★★★  nx
★★★  inventor
★★  autocad
★★  pro e
★★  unigraphics
★  proe
★  mastercam
★  creo
★  pro engineer
★  ug
★  alias
  delmia
  ansys
  solid edge
  solidworks better
  ideas
  abaqus
  pro-e

Your alternative for catia is not listed? Suggest!
Speaking about catia, one probably shouldn't forget about abaqus.

Other search terms related to catia and their ratings are:
★★★★★ abaqus
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Google Trends

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catia
solidworks
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