Most automotive structures are highly complex by nature, and as a result, do not lend themselves readily to hand methods of calculation. Investigation of bus-frame structures generally need a three dimensional analysis of space framework. However, in most cases there could be useful to produce a plainframe computation, especially if the effects of sheet metals are also included. Some of earlier works substituted the bars by triangular elements. It was disadvantageous from two respects:- During transformation of bars it is impossible to take regard the energy corresponding to tension.- Sizes of the bar perpendicularly to its axe are relatively small, so the triangular elements must be "too long" which is very disadvantageous from the point of computerisation or too many elements must be used.This paper presents a plane finite element procedure to analyse a plain model of sideframe containing both bars and sheet metals. The structure is supposed to be linearly elastic, the displacements are small and the loading is static.