Figures 20 and 21 show that the surge speed changes to negative values and the drift angle exceeds the safety limit in the tracking control process of Methods A and B.
The safety limit of drift angle is carried out effectively for safety in the high-speed trajectory tracking process of hovercraft.
Although the ductility coefficient is relatively small, the story drift angle of elastic-plastic is between 1/29 and 1/45, which meets the requirement of the norm, that is, more than 1/50 [23,30].
The dissipation energy capacity of the structure at the drift angle is measured by the area of stress to strain enclosed.
The hysteresis curves of the shear wall are almost linear and the residual drift angle is less than 1/1000.
The ultimate drift angle [[theta].sub.u] is the average value of the pulling and pushing directions.
The drift speed of the ship and the drift angle
depend on wind velocity.
This model includes the approximation that the efficiency reaches its maximum for the common optimum drift angle
[[theta].sub.d] = 3[pi]/4.
Figure 16 shows positive P versus [[theta].sub.L] skeleton curve based on the first cycle of each drift angle
1 includes the main conditions for ships and environment having influence on the maneuverability characteristics of ships: [alpha]--ruder turn angle; L, B, T--geometrical characteristics (length, width, draft etc.) of ships; [D.sub.s]--the diameter of ship propeller; [n.sub.s]--the turning velocity of propellers; [R.sub.a]--aerodynamic loads; [R.sub.v]--waves forces; [R.sub.S]--forces of the influence of shallow waters; v--ship speed; [beta]--ship drift angle
; [omega]--the turning velocity of the ship.
The player earns drift points based on their drift angles
, racing lines, and speeds within evaluation zones located at various turns on the course.