Required test durations for converged short-term wave and impact extreme value statistics — Part 1: Ferry dataset

For the design of maritime structures in waves, the extreme values of responses such as motions and wave impact loads are required. Waves and wave-induced responses are stochastic, so such responses should always be related to a probability. This information is not easy to obtain for strongly non-linear responses such as wave impact forces....

Required test durations for converged short-term wave and impact extreme value statistics–Part 2: Deck box dataset

In the assessment of wave-in-deck loads for new and existing maritime structures typically model tests are carried out. To determine the most critical conditions and measure sufficient impact loads, a range of sea states and various seeds (realisations) for each sea state are tested. Based on these measurements, probability distributions can...

Machine learning approach to railway ballast degradation prognosis considering crumb rubber modification and parent rock strength

Parent rock strength and crumb rubber modification are two critical mechanical parameters that significantly decide the ballast layer degradation subjected to train dynamic loading. Using machine learning to predict ballast degradation considering these two parameters is helpful for deciding ballasted track maintenance cycle. In the current...

A review of impact loads on composite wind turbine blades: Impact threats and classification

A fiber-reinforced composite wind turbine blade (WTB) is exposed to numerous impact threats during its service life causing damages that can be detrimental to its structural integrity. Currently, impact loads are not considered during blade design, so high safety factors are introduced, which result in a conservative design. However, as wind...

Allowable Wind Turbine Set-down Impact

The increased awareness of the negative consequences of man-made climate change has given rise to a fast growing offshore wind industry. Wind turbines become increasingly larger, and available locations for offshore wind farms are shifting towards deeper waters, where jack-up vessels can no longer be used for installation. Heerema Marine...

On the accuracy of predicting cavitation impact loads on marine propellers

Predicting the cavitation impact loads on a propeller surface using numerical tools is becoming essential, as the demand for more efficient designs, stretched to the limit, is increasing. One of the possible design limits is governed by cavitation erosion. The accuracy of estimating such loads, using a URANS approach, has been investigated....

An inter-model comparison for wave interactions with sea dikes on shallow foreshores

Three open source wave models are applied in 2DV to reproduce a large-scale wave flume experiment of bichromatic wave transformations over a steep-sloped dike with a mildly-sloped and very shallow foreshore: (i) the Reynolds-averaged Navier–Stokes equations solver interFoam of OpenFOAM® (OF), (ii) the weakly compressible smoothed particle...

Validation of RANS modelling for wave interactions with sea dikes on shallow foreshores using a large-scale experimental dataset

In this paper, a Reynolds-averaged Navier-Stokes (RANS) equations solver, interFoam of OpenFOAM®, is validated for wave interactions with a dike, including a promenade and vertical wall, on a shallow foreshore. Such a coastal defence system is comprised of both an impermeable dike and a beach in front of it, forming the shallow foreshore...

Magnetic Stray Field Analysis to Detect Plastic Deformation in Steel Cylinders: Experimental Research into Magnetomechanical Effect Under Impact Loading

Pile driving can cause plastic deformation to the head of the driven pile, which in turn can lead to connectivity issues when the superstructure is installed. Moreover, plastic deformation reduces the estimated service life of the structure. Therefore, it is necessary to monitor the strain levels during the installation in order to detect if the...

A feasibility study for the installation of 10 MW offshore wind turbines with an SSCV

Since the oil price collapse at the end of 2014, operators in the offshore industry experience a decline in revenues and a need for downsizing. Simultaneously, the wind industry is growing every year, as an increasing amount of companies and consumers are investing in green energy. This creates opportunities for Heerema Marine Contractors (HMC),...

Structural Strength of Laminated Glass

The subject area "structural strength of materials" is defined generally as а complex of strength characteristics of materials and structural elements, obtained under special mechanical tests. It is shown that these tests should take into account not only the physical and mechanical properties of the material, but technology, blank processing,...

Evaluation of transient lift loads during a decommissioning operation with a crane vessel

With the conversion of a heavy transport vessel into a crane vessel, Boskalis aims to strengthen its position in the offshore wind and decommissioning markets. The BOKALIFT 1, as the crane vessel will be named, is equipped with a 3,000 tonne crane and a class-2 Dynamic Positioning system. In order to utilise its exceptional large and strong deck...

Experimental and Analytical Study of Free-Fall Drop Impact Testing of Portable Products

Portable products can suffer critical damage due to drop impact and thus, such load cases must be taken into account in the conceptual and detailed design phases of such products. One method explored in the current study for alleviating the peak accelerations resulting from impact is to isolate fragile components from the product housing using...

Concrete under Impact Loading, Tensile Strength and Bond

Uniaxial impact tensile tests on plain concrete were carried out with the aid of Split Hopkinson Bar equipment with stress rates of up to 60000 N/mm2. s. Various concrete mixes were investigated under. dry and wet conditions. All the concretes showed an increase in strength with increasing stress rate. At very high stress rates the strength may...

Rekenmodellen voor het botsen van schepen tegen remmingwerken: Theoretische benaderingen voor de invloed van het water

Belastingen op remmingwerken door schepen, varend onder een hoek tegen het remmingwerk