ROV tool to repair fish cages

This thesis deals with one of the main challenges the aquaculture industry is facing today: escapes from fish cages. To avoid or limit the impacts of such events a Remote Operated Vehicle (ROV) mounted tool is proposed and designed. This tool can fix the damaged nets rapidly before escapes can occur. The use of smaller ROVs is growing in the aquaculture industry and this thesis proposes combining an ROV as an observational platform and a repair platform. After evaluating two different methods for the repair, one with the use of cables ties and the other with steel wire, a prototype is described, designed and evaluated. How the tool should be mounted on the ROV depends on the maneuverability of the ROV. Therefore, the degrees of freedom of the chosen ROV is important and addressed in this study. A simulation of the drag coefficient of the tool is carried out to evaluate its characteristics in the water, followed by calculations to determine the necessary performance of the actuators in the tool. The finished design and prototype is functional and shows promise.M-MP

ROV tool to repair fish cages

This thesis deals with one of the main challenges the aquaculture industry is facing today: escapes from fish cages. To avoid or limit the impacts of such events a Remote Operated Vehicle (ROV) mounted tool is proposed and designed. This tool can fix the damaged nets rapidly before escapes can occur. The use of smaller ROVs is growing in the aquaculture industry and this thesis proposes combining an ROV as an observational platform and a repair platform. After evaluating two different methods for the repair, one with the use of cables ties and the other with steel wire, a prototype is described, designed and evaluated. How the tool should be mounted on the ROV depends on the maneuverability of the ROV. Therefore, the degrees of freedom of the chosen ROV is important and addressed in this study. A simulation of the drag coefficient of the tool is carried out to evaluate its characteristics in the water, followed by calculations to determine the necessary performance of the actuators in the tool. The finished design and prototype is functional and shows promise

ROV tool to repair fish cages

This thesis deals with one of the main challenges the aquaculture industry is facing today: escapes from fish cages. To avoid or limit the impacts of such events a Remote Operated Vehicle (ROV) mounted tool is proposed and designed. This tool can fix the damaged nets rapidly before escapes can occur. The use of smaller ROVs is growing in the aquaculture industry and this thesis proposes combining an ROV as an observational platform and a repair platform. After evaluating two different methods for the repair, one with the use of cables ties and the other with steel wire, a prototype is described, designed and evaluated. How the tool should be mounted on the ROV depends on the maneuverability of the ROV. Therefore, the degrees of freedom of the chosen ROV is important and addressed in this study. A simulation of the drag coefficient of the tool is carried out to evaluate its characteristics in the water, followed by calculations to determine the necessary performance of the actuators in the tool. The finished design and prototype is functional and shows promise.M-MP

Experimental and numerical study of notched SHS made of different S355 steels

This study compares the mechanical behaviour of square hollow sections (SHS) made of three different types of S355: cold-formed, hot-rolled and offshore steel. A material model and failure criterion for each steel type were calibrated based on quasi-static uniaxial tensile tests. The failure criterion applies a recently proposed through-thickness damage regularisation model with the purpose of accurately describing the load-bearing capacity using shell elements. Experimental three-point bending tests were conducted at both quasi-static and dynamic conditions. Notches were used to trigger failure in the tests. The cold-formed steel exhibited the highest yield stress of the three steel types, while the offshore steel displayed better ductility than the other two. The numerical simulations showed that a shell element model of the SHS incorporating the regularisation scheme was able to describe the material behaviour and predict failure