TY - CONF A1 - Frei, Vivian A1 - Pirskawetz, Stephan A1 - Thiele, Marc A1 - Rogge, Andreas T1 - Experimental investigation of size effect on fatigue behavior of high strength concrete - concept and preliminary results N2 - The worldwide spread of windfarms brings new challenges, especially for concrete structures as a part of towers, connecting joints and foundations of wind turbines. High-cyclic loadings in such structures lead to a high relevance of the subject of fatigue. A proper assessment of the fatigue strength of concrete demands therefore a basis of reliable experimental data and the development of standardized testing methods. This article presents first results of an ongoing research program of BAM (Bundesanstalt für Materialforschung und -prüfung) which is a part of a joint project (WinConFat) funded by the German Federal Ministry for Economic Affairs and Energy. The subproject investigates the effects of size and slenderness of the specimens on the fatigue behaviour of high strength concrete at different stress levels. Not only the fatigue strength, but also the fatigue process itself is monitored by means of several measurement methods. Strain measurements are used to calculate the load dependent elastic modulus in the fatigue hysteresis as indicators for fatigue development. Furthermore, the application of non-destructive methods like acoustic emission analysis and ultrasonic measurement in laboratory tests gives a deeper insight into damage processes under cyclic loading. The results shall be used to improve design rules for concrete members under fatigue load and to develop or improve non-destructive techniques for in-service structural health monitoring. T2 - 5th International fib Congress: Better - Smarter - Stronger CY - Melbourne, Australia DA - 08.10.2018 KW - Acoustic emission testing KW - Compressive cyclic loading KW - Fatigue KW - High-strength concrete KW - Non-destructive testing KW - Size effect KW - Slenderness effect KW - Ultrasonic testing PY - 2018 SN - 978-1-877040-14-6 SP - 1 EP - 11 AN - OPUS4-46408 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald A1 - Rogge, Andreas A1 - Thöns, S. A1 - Bismut, E. A1 - Straub, D. T1 - A sampling-based approach to identifying optimal inspection and repair strategies for offshore jacket structures N2 - Identifying optimal inspection and repair strategies for offshore jacket structures is a challenging task. We pre-sent an approach, which is based on recent developments in the field of risk-based operation and maintenance planning at the structural system level. The approach utilizes heuristics to define inspection and repair strate-gies at the system level and to reduce the search space of possible strategies. For each defined strategy, the expected service life cost of inspection, repair and failure is evaluated based on simulated inspection and re-pair histories. Subset simulation is applied to compute the conditional repair and failure probabilities required for this analysis. It also forms the basis for simulating inspection and repair histories. The strategy that mini-mizes the expected service life cost is the optimal one in the set of pre-selected strategies. The underlying condition and performance model accounts for the stochastic dependence among the deterioration states of the different structural elements and the structural redundancy. The approach is demonstrated in a case study considering a jacket-type frame. In this study, we essentially vary the inspection interval, the minimum num-ber of inspected components and the target reliability, and identify the combination that minimizes the ex-pected total service life cost. T2 - The Sixth International Symposium on Life-Cycle Civil Engineering (IALCCE 2018) CY - Gent, Belgium DA - 28.10.2018 KW - Steel structures KW - Fatigue KW - Reliability KW - Risk KW - Inspection planning PY - 2018 AN - OPUS4-46432 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Frei, Vivian A1 - Pirskawetz, Stephan A1 - Thiele, Marc A1 - Rogge, Andreas T1 - Experimental investigation of size effect on fatigue behavior of high strength concrete - concept and preliminary results N2 - The worldwide spread of windfarms brings new challenges, especially for concrete structures as a part of towers, connecting joints and foundations of wind turbines. High-cyclic loadings in such structures lead to a high relevance of the subject of fatigue. A proper assessment of the fatigue strength of concrete demands therefore a basis of reliable experimental data and the development of standardized testing methods. This article presents first results of an ongoing research program of BAM (Bundesanstalt für Materialforschung und -prüfung) which is a part of a joint project (WinConFat) funded by the German Federal Ministry for Economic Affairs and Energy. The subproject investigates the effects of size and slenderness of the specimens on the fatigue behaviour of high strength concrete at different stress levels. Not only the fatigue strength, but also the fatigue process itself is monitored by means of several measurement methods. Strain measurements are used to calculate the load dependent elastic modulus in the fatigue hysteresis as indicators for fatigue development. Furthermore, the application of non-destructive methods like acoustic emission analysis and ultrasonic measurement in laboratory tests gives a deeper insight into damage processes under cyclic loading. The results shall be used to improve design rules for concrete members under fatigue load and to develop or improve non-destructive techniques for in-service structural health monitoring. T2 - 5th International fib Congress: Better - Smarter - Stronger CY - Melbourne, Australia DA - 08.10.2018 KW - Acoustic emission testing KW - Compressive cyclic loading KW - Fatigue KW - High-strength concrete KW - Non-destructive testing KW - Size effect KW - Slenderness effect KW - Ultrasonic testing PY - 2018 AN - OPUS4-46366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -