Concern for the dynamic response of ship and offshore structures as required for safety and serviceability assessments, including habitability. This should include steady state, transient and random responses. Attention shall be given to dynamic responses resulting from environmental, machinery and propeller excitation. Uncertainties should be highlighted in numerical analysis, modelling and measurements.
Dynamic response refers to structural vibration or noise. The excitation sources can be environmental, mechanical, or accidental, which may result in structural damage or discomfort. The dynamic response is documented by measurements or numerical approach, and rules and standards may require mitigating actions.
The group consist of 5 members from the academia and 10 from the industry. Their competence is mainly related to ships, which may result in a bias on offshore references.
With a long history in ISSC, again ships and offshore structures are handled separately, but with a common chapter on monitoring and digitalization. The report is divided into topics depending on the excitation source, but with a separate subsection on noise, damping and mitigating actions and standards. This report includes references from fall 2017 with focus on new knowledge of industrial interest. Overlap with other committees is reduced:
- VLFS – Very large floating structures are covered by (V.6) Ocean Space Utilization.
- Structures for renewable energy are covered by (V.4) Offshore Renewable Energy.
- Hydroelastic plastic response is covered by (III.1) Ultimate Strength.
- Accidental loads are included, but plastic deformations are covered by (V.1) ALS
- Monitoring and digitalization may have a different focus than from other committees.
- The excitation sources are covered by (I.2) Loads.
- Rules, standards, and guidelines may overlap in more general cases.
- Standard applications frequently solved have low focus.
Finally, a benchmark is done on structure borne noise comparing numerical calculations with full scale measurements of an accommodation. The degree of variation, error, and uncertainty in the estimates by different methods and organizations are revealed.
