## 3 Results
### Single Module Motion Response Analysis of Offshore Airports  
#### 3.2.1 Hydrodynamic Response  
As seen in Figures 10 and 11, the vertical oscillation response of the rigid floating plate dominates in both wave conditions, and the maximum value reaches about 6 m. Under regular wave conditions, the pendulum response and transverse rocking response of the floating body reached the maximum peak at the first 10 s, the minimum peak at about 20 s, and gradually reached a relatively stable state at 110 s. The effect of cross-waves on the flow displacement amplitude is large, floating up and down about 3 m, until about 180 s, at which it stabilizes. Under irregular wave conditions, the transverse rocking response is similar to the pattern under regular waves: the spreading displacement has a maximum peak at about 10 s, a minimum peak at about 20 s, and stabilizes at about 140 s, while the vertical oscillation response and longitudinal rocking response changed significantly. At an incident wave angle of 0\({}^{\circ}\), the floating body has a small amplitude of vertical displacement. When the incident wave angle is 90\({}^{\circ}\), the droop response curve is similar to that of 30\({}^{\circ}\), producing a large negative displacement, while at 45\({}^{\circ}\), it is similar to that of 60\({}^{\circ}\), producing a large positive displacement, and the stabilization trend is not obvious. The longitudinal rocking response is the same as under regular waves, and the floating body stabilizes at about 180 s under different wave angles. From Figure 12, it is easy to find that the overall displacement under the same wave angle is always greater than the elastic deformation and rigid displacement, and the elastic deformation is greater than the rigid displacement, but the overall displacement is not a simple superposition of the two. Taking 0\({}^{\circ}\) as an example, the overall displacement maximum is 6.0187 m, the elastic deformation displacement maximum is 6.017 m, and the rigid displacement maximum is 6.016 m. So, it can be seen that for the offshore floating body, the scale is huge, and its elastic deformation should not be ignored. Furthermore, regardless of the wave angle, the difference between the three displacement amplitudes along the floating body distribution is small, but with the increase of the wave direction, the amplitude growth is more obvious. Especially when the wave angle is 90\({}^{\circ}\), the amplitude reaches its maximum value when the safety of the floating body at sea is put to a greater test. Figure 10: Time course curve of rigid body displacement under different incident rule waves. (**a**) Pendulum response curve; (**b**) Transverse rocking response curve; (**c**) Longitudinal rocking response curve. Figure 9: Stress under operating sea state. Figure 13 gives a cloud plot of the Von Mises stress variation along the float length when the float is loaded downward to 40, 70, and 140 s at different waves. From the figure, one can obviously see the distribution law of stress value with the change of floating body length: regardless of the wave direction angle, when the floating body is in the path of an incoming wave within 50 m that is slowly increasing, and the stress concentration is at 50 m with a triangular distribution, which is extremely unfavorable, the stress tends to be smooth from 50 to 300 m. At wave angles of 22.5, 67.5 and 86.25\({}^{\circ}\), the floating body showed large stresses of 0.313, 0.305 and 0.307 MPa, respectively, at \(\pm\)3.75\({}^{\circ}\), the stresses were symmetrically decreasing in distribution, and with the increase of loading time, the peak value first decreased and then increased, showing a backward trend. For the rest of the angles, the floating body stress value is smaller and the load bearing capacity is higher. Figure 11: Time course curve of rigid body displacement under different incident irregular waves. (**a**) Pendulum response curve; (**b**) Transverse rocking response curve; (**c**) Longitudinal rocking response curve.