Abstract
M.Ing.
The purpose of this thesis was to gather experimental data of a stainless steel sleeve being formed
into a convoluted tube.
This convoluted tube, made from stainless steel ASTM 240 type 321 and with a wall thickness of
0,4mm, is the main part of an automotive exhaust bellow.
The automotive exhaust bellow fits into a motor vehicle exhaust system. One of the functions of
this bellow is to compensate for engine movement. The bellow is also used to damp the engine
vibration to the vehicle chassis.
Typical failures that occur during the production of a convoluted tube are identified. The data
gathered are listed and the forming process, typical conditions and its effects discussed. The actual
data and graphs are presented in the annexures at the end of this report. Plasticity theory for shells
and cylinders is summarized in Annexure A and the solution of a related problem discussed.
Experimental data were used to verify the result of a finite element model. The calculated values
of the model compare well with the values of the experimental data. The model must still be
developed further and the experimental data can be used to verify this developed model.
Possible aspects, related to the forming and life-cycle prediction of an automotive exhaust bellow,
that still need to be studied are identified and presented at the end of this report.