TY  - JOUR
A1  - Chowdhury, Sharmistha
A1  - Zabel, Volkmar
T1  - Influence of loading sequence on wind induced fatigue assessment of bolts in TV-tower connection block
JF  - Results in Engineering
N2  - Bolted connections are widely employed in structures like transmission poles, wind turbines, and television (TV) towers. The behaviour of bolted connections is often complex and plays a significant role in the overall dynamic characteristics of the structure. The goal of this work is to conduct a fatigue lifecycle assessment of such a bolted connection block of a 193 m tall TV tower, for which 205 days of real measurement data have been obtained from the installed monitoring devices. Based on the recorded data, the best-fit stochastic wind distribution for 50 years, the decisive wind action, and the locations to carry out the fatigue analysis have been decided. A 3D beam model of the entire tower is developed to extract the nodal forces corresponding to the connection block location under various mean wind speeds, which is later coupled with a detailed complex finite element model of the connection block, with over three million degrees of freedom, for acquiring stress histories on some pre-selected bolts. The random stress histories are analysed using the rainflow counting algorithm (RCA) and the damage is estimated using Palmgren-Miner's damage accumulation law. A modification is proposed to integrate the loading sequence effect into the RCA, which otherwise is ignored, and the differences between the two RCAs are investigated in terms of the accumulated damage.
KW  - Schadensakkumulation
KW  - Lebenszyklus
KW  - Fatigue life
KW  - Damage accumulation
KW  - Wind load
KW  - Rainflow counting algorithm
KW  - Loading sequence
KW  - Windlast
KW  - OA-Publikationsfonds2022
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20221028-47303
UR  - https://www.sciencedirect.com/science/article/pii/S2590123022002730?via%3Dihub
VL  - 2022
IS  - Volume 16, article 100603
SP  - 1
EP  - 18
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Chowdhury, Sharmistha
A1  - Kraus, Matthias
T1  - Design-related reassessment of structures integrating Bayesian updating of model safety factors
JF  - Results in Engineering
N2  - In the semi-probabilistic approach of structural design, the partial safety factors are defined by considering some degree of uncertainties to actions and resistance, associated with the parameters’ stochastic nature. However, uncertainties for individual structures can be better examined by incorporating measurement data provided by sensors from an installed health monitoring scheme. In this context, the current study proposes an approach to revise the partial safety factor for existing structures on the action side, γE by integrating Bayesian model updating. A simple numerical example of a beam-like structure with artificially generated measurement data is used such that the influence of different sensor setups and data uncertainties on revising the safety factors can be investigated. It is revealed that the health monitoring system can reassess the current capacity reserve of the structure by updating the design safety factors, resulting in a better life cycle assessment of structures. The outcome is furthermore verified by analysing a real life small railway steel bridge ensuring the applicability of the proposed method to practical applications.
KW  - Lebenszyklus
KW  - Sicherheitsfaktor
KW  - Structural health monitoring
KW  - Safety factor
KW  - Life cycle assessment
KW  - Uncertainty
KW  - Bayesian parameter update
KW  - Ungewissheit
KW  - Umweltbilanz
KW  - OA-Publikationsfonds2022
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20221028-47294
UR  - https://www.sciencedirect.com/science/article/pii/S2590123022002304?via%3Dihub
VL  - 2022
IS  - Volume 16, article 100560
SP  - 1
EP  - 1
PB  - Elsevier
CY  - Amsterdam
ER  -