VL DYNAMICS provides design calculations, and noise and vibration measurements for the marine, energy and industry markets.

Noise and vibration measurements for the maritime industry

Noise and vibration measurements are used to validate and troubleshoot structures.

The company uses world-leading N&V measurement equipment to achieve accurate results in a wide range of fields, including:

  • Noise and vibration
  • Impact response and mobility
  • Airborne sound insulation
  • Reverberation time
  • Local structure and equipment vibration
  • Shaft vibration, torque and power
  • Stress and strain
  • Multichannel setup

VL DYNAMICS’s personnel, software analysis tools and measurement capabilities provide a perfect platform for sea trials and troubleshooting support.

VL DYNAMICS specialises in noise and vibration measurement solutions for the marine industry, including mega yachts.
A-frame refit strength assessment is an example of the company’s finite element (FE) analysis.
The image shows a global FE vibration analysis in 1st torsional mode.
Non-linear structural assessment is used as part of deck penetration study.
The company performs lateral-torsional analysis of a shafting system.
Noise radiation prediction calculations are made on engine rooms featuring two main engines.
The drawing shows the extent of a floating floor, which is based on noise prediction calculation.
Strain gauge measurements on couplings are an example of torsional dynamics.
ME 6th order visible in spectrogram (left) and order plot (right).

Noise prediction solutions

Using numerical analysis tools, VL DYNAMICS predict noise levels throughout ships. Noise predictions should be performed during the early stages of a project.

As the project progresses, noise predictions are used to select optimal noise mitigating measures and optimise room acoustics.

VL DYNAMICS provides noise prediction services for:

  • Structure-borne noise
  • Airborne noise
  • Silencer design optimisation
  • Environmental noise
  • Room acoustics

Mitigating measures typically include floating floors, visco-elastic constraining layers, and machinery vibration isolators. Noise and vibration mitigating measures that are incorrectly installed are costly to change at later stages of a project.

Vibration prediction solutions

An undamped eigenvalue calculation is used to determine the natural frequency of structures including stiffeners, plate panels, deck structures and foundations. Necessary modifications are determined where excitation sources and the calculated eigenvalues coincide.

A forced response calculation determines the behavior of a system to an excitation force, and the calculation provides an outset for design recommendations.

Numerical calculation models are calibrated using measured data.

Strength and fatigue assessments of structures

VL DYNAMICS has extensive experience assessing the structural strength of floating or land-based structures.

Calculation assessments and recommendations are prepared complying with standards and rules specified by national authorities, flag states and classification societies.

A structural assessment typically includes:

  • The evaluation of maximum direct stress and strain
  • Buckling calculation of plate fields
  • Fatigue life calculation for local structural details

The company estimates the state of an entire structure in operation and computes a complete structure assessment using a state estimation finite element (FE) model.

Characteristics assessed include:

  • Stress and strain
  • Accelerations, displacements and velocity
  • Fatigue life
  • Crack propagation
  • Modal partition factors

Eigenvalue prediction of rotating systems

Using VL DYNAMICS’s Mimer™ software, the eigenvalues for an undamped and damped shafting system are calculated, including effects from support stiffness, bearings and coupling dynamics.

Using Mimer, the coupled torsional-lateral response at the gear foundation can be calculated providing crucial understanding to the N&V performance of the gear.

Design modifications are generated by calibrating the as-built numerical Mimer shafting system prediction model with on-site measurement data. Using the prediction model, the system response to applied modifications is calculated prior to expensive downtime and installation costs.

Condition-based maintenance monitoring

VL DYNAMICS’s Heimdal™ system is a simple and easy-to-use condition monitoring system, which is based on many years of tested theory and practical knowledge.

A standalone integrated software-hardware product, Heimdal allows clients to easily monitor one or several machines simultaneously, and in accordance with recognised industry rules, regulations and standards.

The system is an interactive graphic of all or a selection of recorded data that allows the operator to concurrently investigate one or more of an infinite number of signals.

All Heimdal systems are configured by VL DYNAMICS, based on the type of equipment and system, recognised industry standards, and specific client requirements.

Failure investigation and troubleshooting

VL DYNAMICS is experienced in troubleshooting assignments, by combining extensive knowledge of N&V issues and dynamic systems.

Whether it is noise related comfort issues, structures failing due to heavy vibrations or rotating equipment failing unexpectedly, the company describes the current state of a unit and provides modification recommendations, generating time and money savings.