Comprehensive analysis of the seismic wave fields generated by offshore pile driving: A case study at the BARD Offshore 1 offshore wind farm.

Offshore pile driving not only generates high sound pressure levels, but also induces ground vibrations and particle motions that have the potential to affect fish and invertebrates living near or in the seabed. In particular, the seismic wave field in the form of interface waves is thought to be responsible for causing these particle motions and ground vibrations. However, the magnitude and spatial extent of the seismic wave field resulting from pile driving has not been clearly established.

Modeling the noise mitigation of a bubble curtain.

The bubble curtain is one of the most used measures to reduce underwater pile driving noise. A model of the local distribution of the effective wavenumber was developed. The bubble size distribution was derived from tank measurements.

A Co-Rotational Based Anisotropic Elasto-Plastic Model for Geometrically Non-Linear Analysis of Fibre Reinforced Polymer Composites: Formulation and Finite Element Implementation.

Geometrical non-linearity is one of the aspects to be taken into account for accurate analysis of fibre reinforced polymers (FRPs), since large displacements and rotations may be observed in many of its structural applications such as in aircraft wings and wind turbine blades. In this paper, a co-rotational formulation and implementation of an invariant-based anisotropic plasticity model are presented for geometrically non-linear analysis of FRPs. The anisotropic constitutive equations are formulated in the format of isotropic tensors functions.

Evaluation and Modeling of the Fatigue Damage Behavior of Polymer Composites at Reversed Cyclic Loading.

Understanding the composite damage formation process and its impact on mechanical properties is a key step towards further improvement of material and higher use. For its accelerated application, furthermore, practice-related modeling strategies are to be established. In this collaborative study, the damage behavior of carbon fiber-reinforced composites under cyclic loading with load reversals is analyzed experimentally and numerically.

Influence of Reversed Fatigue Loading on DamageEvolution of Cross-Ply Carbon Fibre Composites.

Microcrack formation and delamination growth are the main damage mechanisms in thefatigue of composites. They lead to significant stiffness loss, introduce stress concentrations andcan be the origin of subsequent damage events like buckling or fibre breakage, especially in case ofshear and compression stresses during load reversal. Fatigue experiments of carbon fibre reinforcedlaminates were conducted at several stress ratios and analysed in terms of crack and delaminationgrowth.

Towards a complete physically based forecast model for underwater noise related to impact pile driving.

An approach for the prediction of underwater noise caused by impact pile driving is described and validated based on in situ measurements. The model is divided into three sub-models. The first sub-model, based on the finite element method, is used to describe the vibration of the pile and the resulting acoustic radiation into the surrounding water and soil column.

Investigation of sonar transponders for offshore wind farms: modeling approach, experimental setup, and results.

The installation of offshore wind farms in the German Exclusive Economic Zone requires the deployment of sonar transponders to prevent collisions with submarines. The general requirements for these systems have been previously worked out by the Research Department for Underwater Acoustics and Marine Geophysics of the Bundeswehr. In this article, the major results of the research project "Investigation of Sonar Transponders for Offshore Wind Farms" are presented.