# Wind-Load Response and Evacuation Efficiency Analysis of Marine Evacuation Inflatable Slide
## 1 Introduction  
With the increasing dependence of economic development on marine trade, shipping routes are complex and the incidence of various maritime accidents is gradually increasing [1]. The ocean evacuation system is a kind of lifesaving equipment which can effectively and safely complete the evacuation of ship distress personnel [2]. The importance and urgency of its research and development are being paid attention by researchers in related fields. The inflatable slide evacuation system is a kind of lifesaving equipment mainly used in the evacuation of distressed persons on roll-on ships. Generally, it is composed of an evacuation box frame, integrated inflatable slide and sea mounting platform, telescopic guide rail, load-carrying frame and air charging device [3]. The whole system, as shown in Figure 1, is stored in the evacuation frame and fixed on the decks on both sides of the shipboard in the receiving state. When the evacuation system is in operation, the slide and the sea lifesaving devices are inflated and deployed, and the connecting cables are fixed on the side of the ship to ensure the stability of the sea lifesaving devices. As shown in Figure 2, the external geometry of the inflatable slide is irregular, and its surface is made of rubber film, which bears a large area of wind load. At present, there is no validation standard for the response state of a lifesaving inflatable slide under wind load. In practical engineering, the displacement, deformation and wind pressure distribution of flexible film under wind load generally need to be obtained by aeroelastic model wind tunnel test. This method has a long test period, a large investment, and often uses the scaled rigid model in the test, ignoring the effect of fluid-solid coupling effect, and cannot completely and accurately reflect the actual situation. Experts and scholars in related fields have made pioneering explorations on the application of finite element numerical simulation methods in response analysis of flexible membrane structures. With the deepening of research and the development of scientific research means, the physical model test method is gradually replaced by the computer numerical simulation analysis method [4]. [PERSON] carried out wind tunnel tests on the umbrella rigid roof structure, changing wind speed, wind direction and other conditions, and obtained the corresponding fluid pressure distribution of different input parameters on specific structure, and further obtained the law of fluid pressure  
Figure 1: Storage status diagram of a marine evacuation system. 1-life raft, 2-integrated inflatable slide and sea mounting platform, 3-telescopic guide rail, 4-load-carrying frame, 5-air changing device, 6-pulley set receiving and placing mechanism. Figure 2: Deployment status diagram of marine evacuation system. 1-anchorage point, 2-anchor wires, 3-inflatable life rafts, 4-inflatable slide, 5-boarding platform. distribution [5]. [PERSON] carried out data transmission between CFD (computational fluid dynamics) and CSD (computational structural dynamics) through an intermediate data exchange platform. The indirect calculation method was used to simulate the fluid-structure coupling between wind and membrane structures [6]. A time-varying fluid-structure coupling method for thin shell large displacement membrane structures was also proposed [7]. [PERSON] used the numerical simulation method of interaction between the enclosed saddle-shaped membrane and wind to study structural vibration and the interaction's effects on the membrane's wind response [8]. [PERSON] studied fluid-structure interaction of hemispherical membrane structures of three Reynolds numbers (50,000, 75,000, 100,000) by using wind tunnels, and obtained deformation responses of hemispherical membrane structures under different flow conditions [9]. [PERSON] investigated the wind load and wind environment of three typical air-supported membrane structures with different rise-span ratios in different wind directions by using the LK k-\(\varepsilon\) model [10].