A total of 16 identical car bodies have been fatigue tested to failure in two laboratories under well defined and controlled conditions at Land Rover and Volvo Cars. Nine bodies were tested under CA (constant amplitude) loading and seven under VA (variable amplitude) loading. Scatter in fatigue tests was quantified by performing several identical tests. Fatigue failures in sheet metal, spot welds and seam welds werde detected during frequent insepctions. Life predictions have been carried out in parallel using the commercial finite element (FE) based fatigue packages FE-Fatigue and LMS-Falancs. State-of-the-art FE-modelling, including mesh incompatible, spot weld modelling, has been utilised. Scatter in test results is found to be almost identical for sheet metal, spot welds and seam welds. Test results differ less than a factor of 1.4 from average life for VA testing and a factor of 1.7 for CA testing. A damage sum 3 to 4 times lower is needed for VA predictions as compared to CA predictions. Sheet metal fatigue is typically within a factor of 2 from predicted, whereas spot weld and seam weld predictions tyically are within a factor of 4 to 5 from predicted. The project has given good insight on the achievable accuracy level in fatigue life estimations on a BIW system tested under controlled laboratory conditions.
Statistical correlation of measured and predicted fatigue life of car bodies tested under constant and variable amplitude loading
Statistische Korrelation von gemessenen und berechneten Lebensdauern von PKW-Karosserien unter Belastung mit konstanten und variablen Amplituden
2004
2 Seiten, 8 Bilder, 1 Tabelle, 19 Quellen
Conference paper
English
British Library Conference Proceedings | 2004
|Short surface fatigue cracks growth under constant and variable amplitude loading
Tema Archive | 2009
|Low Cycle Fatigue of Spot Welds Under Constant and Variable Amplitude Loading
British Library Conference Proceedings | 2003
|