Harald Zenner

Understanding the fatigue behaviour of structural components under variable load amplitude is an essential prerequisite for safe and reliable light-weight design. For designing and dimensioning, the expected stress (load) is compared with the capacity to withstand loads (fatigue strength). In this process, the safety necessary for each particular application must be ensured. A prerequisite for ensuring the required fatigue strength is a reliable load assumption. The authors describe the transformation of the stress- and load-time functions which have been measured under operational conditions to spectra or matrices with the application of counting methods. The aspects which must be considered for ensuring a reliable load assumption for designing and dimensioning are discussed in detail. Furthermore, the theoretical background for estimating the fatigue life of structural components is explained, and the procedures are discussed for numerous applications in practice. Oneof the prime intentions of the authors is to provide recommendations which can be implemented in practical applications.

Understanding the fatigue behaviour of structural components under variable load amplitude is an essential prerequisite for safe and reliable light-weight design. For designing and dimensioning, the expected stress (load) is compared with the capacity to withstand loads (fatigue strength). In this process, the safety necessary for each particular application must be ensured. A prerequisite for ensuring the required fatigue strength is a reliable load assumption. The authors describe the transformation of the stress- and load-time functions which have been measured under operational conditions to spectra or matrices with the application of counting methods. The aspects which must be considered for ensuring a reliable load assumption for designing and dimensioning are discussed in detail. Furthermore, the theoretical background for estimating the fatigue life of structural components is explained, and the procedures are discussed for numerous applications in practice. Oneof the prime intentions of the authors is to provide recommendations which can be implemented in practical applications.

Be­triebs­fes­tig­keit be­deu­tet die si­che­re Be­mes­sung von Bau­tei­len un­ter re­a­lis­ti­schen Um­ge­bungs­be­din­gun­gen mit dem Ziel Leicht­bau. Im Mit­tel­punkt steht die Schwing­be­an­spru­chung. Bei der Be­mes­sung wird die zu erwartende Be­an­spru­chung (Be­las­tung) mit der Be­an­spruch­bar­keit (Fes­tig­keit) verglichen, wo­bei die für den An­wen­dungs­fall not­wen­di­ge Si­cher­heit ge­währ­leis­tet wer­den muss. Vo­raus­set­zung für die be­triebs­fes­te Be­mes­sung ist eine zu­ver­läs­si­ge Last­an­nah­me. Die Autoren stellen dar, wie die im Be­trieb ge­mes­se­nen Be­an­spru­chungs­zeit­funk­ti­o­nen durch Zähl­ver­fah­ren in Kol­lek­ti­ve oder Ma­tri­zen trans­for­miert wer­den kön­nen. Aus­führ­lich be­han­delt wird, wel­che As­pek­te zu be­ach­ten sind, um eine zu­ver­läs­si­ge Last­an­nah­me für die Be­mes­sung si­cher­zu­stel­len. Dazu wird ein­mal der the­o­re­ti­sche Hin­ter­grund der Le­bens­dau­er­ab­schät­zung von Bau­tei­len er­läu­tert, zum an­de­ren wer­den die Vor­ge­hens­wei­sen in zahl­rei­chen tech­ni­schen An­wen­dungs­fäl­len dis­ku­tiert. Für die Pra­xis um­setz­ba­re Emp­feh­lun­gen zu ge­ben, ist ein we­sent­li­ches An­lie­gen der Au­to­ren.