Abstract
For lightweight automotive structures, the stiffness and the fatigue behaviour is greatly influenced by the properties of its joints. The used joining technology, the number and locations of the spot joints are of high importance for both engineers and cost accountants. New computational procedures are presented for assessing the stiffness and fatigue behaviour of thin sheet structures including joints in the form of spot and arc welds. It is shown that standardised meshing is necessary for a correct representation of local stiffness as well as fatigue behaviour. The stresses from these automatically generated shell elements are used in combination with a test result database for accurate prediction of lifetime for a broad range of parameters like sheet thickness, material and nugget diameter. Fatigue analyses can be performed for uni-axially as well as multi-axially loaded components using an unlimited number of load channels.