Part 12: Frame stress analysis
Allan Wallace, a mutual friend of John and Bryan, has kindly donated his expertise to carry out finite element analysis of the proposed new frame structure. He has also completed a similar analysis of the old frame.
Whilst the stress model allows for axle loadings, drawbar pull and piston loads, it is not refined to the extent of allowing for dynamic stresses. However, the main purpose was one of comparison, and this demonstrates that much of the high stress in the original frame is considerably eased in the new. It is comforting to note that the predicted high stress points correlate very well with the actual crack locations in the old frame.
The pictures shown here are extracted from the computer modeling program. It would be interesting (and a little bit scary) if we were able to show the contortions of the frame as the stresses vary.