Date: Fri, 21 Jan 2000 21:59:55 +0000 From: Johannes H Andersen <johsnopsamsafish.com> Subject: Re: 9-5 Structural failure WEB site
Goran Larsson wrote: > > > I still think that the left rear wheel hit some fixed object while > the car was moving backwards at high speed. > Picture 5-6 shows that there were 2 fractures. The first fracture was cought by a round hole in the middle of the member. This left a small cross section in the member, now less than half the width. Nevertheless the second and final fracture happened in a different place where the the member was much wider that what was left by the first crack. Cracks can propagate in a brittle material, once started they continue until cought by e.g a hole. This suggest to me that there must have been some initial seed for the crack in the member. Otherwise the member would have broken off near the first crack. Possibly the break was forced by a load on the wheel. Is he telling us the whole story ? Nevertheless this should not happen, an estate car is normally stronger buildt than the saloon car equivalent. Johannes