Software-to-Software Comparison of End-Anchored Floating Bridge Global Analysis

Abstract

Several computer programs exist to handle general multi-purpose offshore structural analysis of slender structures subjected to wave loading, although, they have not been developed with the specific purpose of floating bridge global analysis in mind. Due to the inherent complexity of a floating bridge structure, this poses a valid concern regarding the accuracy in the calculated response. Normally, the intended computer program is validated against experiments but in the case of extremely long floating bridges the size limitations of existing ocean basins necessitates the use of hybrid testing where the computer program is a part of the method to obtain the true value from the experiments. It is, therefore, crucial to get an overview of how sensitive the numerical results are to inaccurate user inputs, approximations introduced in the theory and the software implementation of the theory as well as possible settings that the user does not have access to. An extensive comparison between two commonly used commercial computer programs in the offshore industry is presented in the present paper for a global analysis of a floating pontoon bridge concept. The comparison includes modal properties as well as deterministic and stochastic structural response 1Viuff, November 8, 2019due to wave loads based on coupled hydro-elastic time domain simulations. First and second order wave loads are included in the comparison as well as viscous drag. The study indicates a reasonable agreement in the response acquired by the two computer programs and highlights consequences of differences in some of the input parameters.

Review of annual progress of bridge engineering in 2019

“…Their results show that turbulent wind can cause noticeable larger resonant responses than the wave loads and current contributes the damping effects, thus reducing the variations of sway motion, axial force, and strong axix bending moment. Viuff et al (2019Viuff et al ( , 2020 and Viuff (2020) evaluated the uncertainty of the wave-and current-induced global extreme response of the curved floating pontoon bridge by considering different main wave directions and compared two common computer programs, Sima and OrcaFlex.…”

An experimental investigation on the hydrodynamic performance of floating bridge foundation with taut mooring system

“…Also for this concept, the effects of wave directionality on bridge extreme response were numerically studied by Viuff et al (2019), and results indicate that the structural response is less sensitive to the natural occurring short-crested waves and the main wave directions within 15°from beam sea. Viuff et al (2020aViuff et al ( , 2020b) also conducted the investigations on the numerical modelling of floating bridges, which improved the understanding of numerical simulation techniques for such type of structures under environmental loadings. Based on numerical time domain analysis, Wei et al (2019) investigated the effects of the wave inhomogeneity on the hydro-elastic responses of a multi-span floating bridge with 19 pontoons, during which different wave spectra were defined for divided regions along the bridge axis.…”