This study focuses on the structure analysis and the dynamic response of the submerged cage net system. The research contents basically include two parts: (1) establishing a numerical model, which is able to predict the cable tension and the change rate of the cage net volume under the attack of typhoon waves; (2) implementing a hydrodynamic physical model test with model scale 1/30, which is installed in the water tank to determine the tension of mooring cable at the anchor.
The comparison of the results of the numerical model and the experimental data has shown a good agreement in the cable tension, which means that the numerical model is reliable and could be used to predict any cage net system with different configurations. Based on the numerical model, 1 – 6 cages net system has been calculated. The results indicate that the 6 cages net system is the worst case. For floating collar on the water surface, its maximum tension is about 14000 kg, but if the floating collar submerged under water surface 8m, the maximum tension will reduce to 10000 kg. Similarly, the minimum change rate of cage net volume may increase from 30% (floating collar on the water surface) to 50% (floating collar submerged in the water). Thus we strongly suggest that the floating collars have to be submerged during typhoon coming, not only because the reduction of mooring cable tension but also increase the fish survival space.