Construction of a mathematical model to describe the dynamics of marine technical systems with elastic links in order to improve the process of their design

Polish Maritime Research

Tarełko

2020

The paper deals with issues connected with the behaviour of a streamer cable towed by a survey seismic vessel when the cable undergoes a strike triggered by collision with an underwater moving object. The consequences of such collisions may be both threat to the life of marine animals or damage to underwater units and large economic losses suffered by vessel owners. The risk of such collisions has increased over the last years as a result of increased offshore seismic survey operations. Therefore, a towed streamer should be very robust. To assure its robustness, we should know the deformation mechanism of a single streamer cable. This in turn requires the development of an appropriate mathematical model of such a phenomenon.In particular, the paper presents the characteristics of seismic survey vessels and streamers; an analysis of collisions that have occurred in the past; a statement of the problem, and a computer-aided system supporting simulation of the cable behaviour. To obtain all the necessary design parameters regarding the deformation mechanism of a streamer cable, we set up a dedicated computer-aided system that supports their calculation.

“…The potential energy Π of the tensioned cable can be determined by (2) or can be expressed as follows:…”

Section: Statement Of the Problemmentioning

confidence: 99%

Section: Computer-aided System Supporting Simulation Of the Cable Behmentioning

confidence: 99%

Section: Computer-aided System Supporting Simulation Of the Cable Behmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Determination of Additional Tension in Towed Streamer Cable Triggered by Collision with Underwater Moving Object

Блинцов

Polish Maritime Research

Tarełko

2020

“…However, it should be noted that a given model does not give a pattern of changes in the rigidity of FL over time; in addition, the equations take a complex form and cannot be used in engineering calculations. This is the approach used in work [14].…”

Section: Introductionmentioning

confidence: 99%

Improving the designing of marine tethered systems using the principles of shipbuilding 4.0

Blintsov

2021

EEJET

Self Cite

This paper considers the issues and theoretical aspects related to improving the design of maritime tethered systems (MTSs) with flexible links (FLs) using underwater towed systems (UTSs) as an example. That allows them to be used in the early stages of design by implementing the principles of Shipbuilding 4.0 and BIM technologies. Such regimes have not previously been described by existing mathematical models (MMs). The expected result of the current study is a significant decrease in the cost of different resources. At the same time, the basic reliable results of design solutions could be obtained already in the early stages of design. The theoretical basis of the proposed method for improving the design of MTS with FL is the improved design concept (IDC) for MTS with FL while the tool base of the method is a special modeling complex (SMC). The use of IDC along with SMC at the research (pre-prototype) design phase reduces the number of MTS design stages. The proposed method to improve the design of MTS with FL, based on the MM that notates the dynamics of MTS FL and MTS with FL, makes it possible to investigate different modes of operation of almost all MTS classes. That allows devising the recommendations for predicting possible operational loads in order to design their elements. At the same time, there is an opportunity to improve the existing methods for calculating and designing MTS with FL with the required properties and parameters, and to bring them to the level of engineering application. The application of SMC at the pre-prototype design stage makes it possible to avoid the use of physical modeling of the operational regimes of MTS with FL associated with the full-scale testing on the high seas

Mathematical Model of Flexible Link Dynamics in Marine Tethered Systems Considering Torsion and its Influence on Tension Force

Polish Maritime Research

2023

Self Cite

The rigidity in bending of a flexible link (is an important characteristic that should be considered during regular service conditions. The tension and bending with torsion of wire ropes are also significant factors. This study proposed a method to calculate the vectors of the generalised forces of bending of flexible links. One of the causes of torsional stresses in the power plant of underwater tethered systems is the interaction with ship equipment, such as spiral winding on the winch drum, friction on the flanges of the pulleys or winch drums, and bends on various blocks and rolls that cause torsion. The source of torsional stresses in the FL may also be related to manufacturing, storage, transportation, and its placement on the ship’s winch drums. Torsion can lead to a decrease in the tensile strength due to load redistribution between power elements, or even a violation of their structure. In some cases, torsion significantly affects the movement of the underwater tethered system as a whole. The development of a mathematical model to describe the marine tethered systems dynamics, taking into account the effect of torsion, is important and relevant. The mathematical model of the marine tethered systems dynamics was improved and solved by accounting for the generalised forces of the torsion rigidity of the flexible link, using an algorithm and computer program. The influence of the bending and torsional rigidity of the FL on its deflection and tensile strength were considered based on the example of two problems. The developed program’s working window image shows the simulated parameters and the initial position of the flexible link. The results show that torsion has almost no effect on the shape of the a flexible link’s deflection in the X0Z plane, but leads to a deviation from the X0Z plane when calculating the static deflection of the flexible link. When the carrier vessel is stationary and the submersible vehicle has no restrictions on movement and has positive buoyancy, torsion leads to a three-dimensional change in the shape of the flexible link both in the X0Z plane and in the X0Y plane. The tension force of the flexible link along its length is distributed unevenly, and the torsion of the flexible link can lead to significant changes in its shape, the trajectory of towed objects, and the forces acting on the elements of the marine tethered systems