TY - JOUR A1 - Kavrakov, Igor A1 - Legatiuk, Dmitrii A1 - Gürlebeck, Klaus A1 - Morgenthal, Guido T1 - A categorical perspective towards aerodynamic models for aeroelastic analyses of bridge decks JF - Royal Society Open Science N2 - Reliable modelling in structural engineering is crucial for the serviceability and safety of structures. A huge variety of aerodynamic models for aeroelastic analyses of bridges poses natural questions on their complexity and thus, quality. Moreover, a direct comparison of aerodynamic models is typically either not possible or senseless, as the models can be based on very different physical assumptions. Therefore, to address the question of principal comparability and complexity of models, a more abstract approach, accounting for the effect of basic physical assumptions, is necessary. This paper presents an application of a recently introduced category theory-based modelling approach to a diverse set of models from bridge aerodynamics. Initially, the categorical approach is extended to allow an adequate description of aerodynamic models. Complexity of the selected aerodynamic models is evaluated, based on which model comparability is established. Finally, the utility of the approach for model comparison and characterisation is demonstrated on an illustrative example from bridge aeroelasticity. The outcome of this study is intended to serve as an alternative framework for model comparison and impact future model assessment studies of mathematical models for engineering applications. KW - Brücke KW - Aerodynamik KW - Aeroelastizität KW - bridge KW - abstract modelling KW - category theory KW - bridge aerodynamics KW - bridge aeroelasticity KW - aerodynamic models KW - model complexity KW - OA-Publikationsfonds2019 Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20190314-38656 UR - https://royalsocietypublishing.org/doi/10.1098/rsos.181848 IS - Volume 6, Issue 3 ER - TY - JOUR A1 - Kavrakov, Igor A1 - Kareem, Ahsan A1 - Morgenthal, Guido T1 - Comparison Metrics for Time-histories: Application to Bridge Aerodynamics N2 - Wind effects can be critical for the design of lifelines such as long-span bridges. The existence of a significant number of aerodynamic force models, used to assess the performance of bridges, poses an important question regarding their comparison and validation. This study utilizes a unified set of metrics for a quantitative comparison of time-histories in bridge aerodynamics with a host of characteristics. Accordingly, nine comparison metrics are included to quantify the discrepancies in local and global signal features such as phase, time-varying frequency and magnitude content, probability density, nonstationarity and nonlinearity. Among these, seven metrics available in the literature are introduced after recasting them for time-histories associated with bridge aerodynamics. Two additional metrics are established to overcome the shortcomings of the existing metrics. The performance of the comparison metrics is first assessed using generic signals with prescribed signal features. Subsequently, the metrics are applied to a practical example from bridge aerodynamics to quantify the discrepancies in the aerodynamic forces and response based on numerical and semi-analytical aerodynamic models. In this context, it is demonstrated how a discussion based on the set of comparison metrics presented here can aid a model evaluation by offering deeper insight. The outcome of the study is intended to provide a framework for quantitative comparison and validation of aerodynamic models based on the underlying physics of fluid-structure interaction. Immediate further applications are expected for the comparison of time-histories that are simulated by data-driven approaches. KW - Ingenieurwissenschaften KW - Aerodynamik KW - Brücke KW - Bridge Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200625-41863 UR - https://ascelibrary.org/doi/10.1061/%28ASCE%29EM.1943-7889.0001811 N1 - This material may be downloaded for personal use only. Any other use requires prior permission of the American Society of Civil Engineers. This material may be found at https://ascelibrary.org/doi/10.1061/%28ASCE%29EM.1943-7889.0001811. N1 - This is the final draft of the following article: https://ascelibrary.org/doi/10.1061/%28ASCE%29EM.1943-7889.0001811, which has been published in final form at https://doi.org/10.1061/(ASCE)EM.1943-7889.0001811 ER -