Zuverlässigkeitsmethoden zur Beschleunigung von Qualifizierungsuntersuchungen für Steckkontakte

Description

This thesis developed and analytically evaluated three consecutive but independent methods for accelerating thermal qualification tests of automotive contacts. First, introduction of micro movements in the contact zone at constant elevated temperatures via a specific test setup, did not to cause statistically significant damage. This was due to the lack of passing the dew point and condensation of moisture in the contact zone. Second, the car usage behavior in Europe was analyzed and transferred to more realistic load profiles. These were carried out in relative motion tests at constant elevated temperatures and as a load profile based on thermal cycles. Only the thermal cycling load-profile was able to cause significant damage in the contact zone faster than in regular thermal cycling tests. Third, a methodology combined calibrated lifetime tests (CALT) with analytical methods for lifetime prediction. The modified Norris-Landzberg model provided a suitable and conservative lifetime prediction for the given connector application. In direct comparison with the conventional CALT-methodology, the combined method dramatically improved the prediction accuracy.
Therefore, the combination of the CALT methodology with acceleration models constitutes a promising way to assist lifetime assessment during development of new contacting technologies. Especially research projects benefit from the methodical way of estimating the lifetime at an early stage. This work was funded by the European Union’s European Regional Development Fund (ERDF).