DMaC_Cable_Bend

Cable bend restrictor test

DMaC_Wet_Rope

Wet rope test

DMaC_Novel_Mooring

Novel Mooring test

Test bed and linear actuator

Dynamic Marine Component (DMaC) Test Facility

The Dynamic Marine Component (DMaC) test facility is a purpose built test rig that aims to replicate the forces and motions experienced by marine components in offshore applications. The test facility is based within the Renewable Energy Research Group of the University of Exeter at Penryn Campus, Cornwall.

The test rig consists of a linear hydraulic cylinder at the tailstock that applies the tension and compression forces or displacements. At the other end of the rig, the headstock with three degrees of freedom can apply bending moments (torque) and angular displacements. The combination of forces and motions from the headstock and tailstock simulate the loads and displacements experienced by a floating body. The working principles are illustrated in figure 1 below. For example, the tailstock can replicate heave motion (Z) and the headstock can replicate pitch (Øx), roll (Øy) and yaw (Øz) motions.

The rig is capable of replicating dynamic tensile forces up to 20 tonnes, static tensile forces up to 40 tonnes, and displacements up to 1 m. The maximum bending angle at the headstock is ±30º for pitch and roll with up to 10 kN·m of bending moment. The maximum torque or yaw is 10 kN·m with an infinite rotational displacement. Beyond that, the rig has the unique feature that components can be submerged in fresh water to allow testing in a wet environment. These features allow dynamic testing of large-scale components under controlled conditions with realistic motion or load characteristics.

This unique combination of features have allowed the DMaC test facility to support studies in to a variety of marine components including: conventional mooring ropes, compliant mooring components, subsea power cables, bend restrictors for power cables, aquaculture components, power take off devices for MRE and even acoustic monitoring of components. These studies are commonly part of national and international collaborative projects and are used to inform performance characterisation, peak or fatigue load assessment, reliability studies and accelerated test campaigns. Furthermore, test work has been conducted to international standard.

Download the DMaC specification sheet

Working principles of the DMaC test rig:

DMAC_Schematic

 HeavePitch and RollYaw
Force 400 kN (max) 10 kN-m 10 kN-m
Displacement 1m 30° Infinite
Speed 0.1 m/s 120° 10rpm

Click on the brochure to enlarge it and see it full screen. Alternatively, you can download a copy.

 

DMaC test facility have performed a huge range of project with collaboration from varying industrial and academic partners. More details can be found in the brochure. The following is a list of example projects and below that are videos to accompany the example projects and case studies in the brochure:

  • Synthetic fibre robes
  • Highly compliant elastomeric mooring components
  • Mooring load control systems
  • Marine power cables
  • Cable bend restrictors and stifferners
  • Power take off devices
  • Conventional mooring components (e.g. chain and shackles)
  • Aquaculture components
  • Acoustic monitoring of marine components
  • General tension and bending assessments

Videos of our example projects:

Click on the links below to be redirected to a YouTube video demonstration [new window].

The following is lists of the publications associated with work completed at DMaC test facility including 1) Conventional mooring lines, 2) Compliant, elastic mooring lines, 3) Subsea power cables and bend restrictors, 4) Reliability studies and 5) Acoustic monitoring.

1. Conventional mooring lines

2. Compliant, elastic mooring lines

3. Subsea power cables and bend restrictors

4. Reliability Studies

5. Acoustic monitoring

Certification

The Quality Management System of DMaC test facility is accredited to ISO 9001:2015 by the British Standards Institute. The accreditation is applicable to:

THE DESIGN, TEST AND REPORT ON EXPERIMENTAL SERVICES OF MARINE COMPONENTS.

Quality Policy - The management team of the Dynamic Marine Component (DMaC) test facility aims to consistently provide a high-quality experimental service that meets or exceeds the clients’ requirements by:

  • Operating at the greatest achievable accuracy of driving parameters (i.e. requested forces and motions), boundary conditions and measurements.
  • Ensure traceability for critical processes, such as calibration and data analysis.
  • Prioritises safety of personnel and equipment.
  • Continual improvement of quality through process and equipment evaluation and enhancement.
  • Implementing and maintaining a quality management system certified against BS EN ISO 9001:2015.

Standards

The DMaC test rig aims to provide a Class 1 uniaxial testing machine, according to ISO 7500-1:2004. Class 1 test machines have relative errors of accuracy and repeatability less than ±1% and 1% respectively.
Test work has been conducted to international standards. For example, fibre ropes for offshore stationkeeping (ISO 19336:2015 and ISO 18692:2007) and subsea power cables (DNV-RP-F401 and Cigre Technical Brochure 623).

Certification and Standards list as shown above if required.

Please contact the DMaC team to discuss your experimental requirements:

University Offices
University of Exeter
Penryn Campus
Penryn
Cornwall
TR10 9FE

Test Facility
Building 420
The Docks
Falmouth
Cornwall
TR11 4NR

Email: DMaC@exeter.ac.uk