Abstract: In order to layout powertrain in a space-limited engine cabin reasonably, it is
required to determine powertrain dynamic envelope. Both conversion of powertrain mathematic
model and simplification of envelope-analog under all circumstances could be realized by using
coordinate transformation and special points extraction. The research aided by CAA, the secondary
development tool of CATIA, is trying to produce an analyzing module which can stimulate
powertrain dynamic envelope to simplify its data, reduce calculating time and improve efficiency.

Key words: computer application, dynamic envelope analysis, transformation of coordinate;
powertrain, envelope surface formation