( 2 ) taking the vehicle platform variant as precondition , this paper deeply researches the function - structure and function - structure decomposition of rear - axle . the rear - axle product model for variant design is built using general cad software ( unigraphics ) ( 2 )以滿足平臺改型設計需求為前提,深入研究了汽車后橋的功能結構和功能結構分解,利用通用cad軟件( unigraphics )建立了適應變型設計的汽車后橋產品模型。