Air-rib tents are widely used because they are lightweight and site adaptable, but the large deformation of these tents reduces their effective space. It is important to reduce the displacement of the air-rib tent by parameter optimization. The influences of external factors on the tent are studied in this paper. Four parameters of the tent’s wind ropes are the angle of the wind ropes, the number of the wind ropes, and the initial prestress of the wind ropes on the side or end faces. The influence of the angle of the wind ropes and the number of the wind ropes on the displacement is larger than the other two parameters. The closer the wind ropes are to the center of the tarpaulin, the greater the displacement of the tent. Based on an analysis using response surface methodology, the optimal parameters are as follows: the angle of the wind ropes is 41°, the number of the wind ropes on the side is two, the initial prestress of the wind ropes on the end face is 800 Pa, and the initial prestress of the wind ropes on the side is 0 Pa. Under these optimal parameters, the maximum displacement decreases by 10.2%, and the maximum stress barely changes.
Air ribs are the critical components of tents. Ten air ribs were designed to study the influence of rise–span ratios on load-bearing performance and explore the failure mechanism. According to the maximum stress that appears at the top and bending regions of the rib, the ribs can be divided into an upright region and an arc-like region. So, a segmentation failure competition mechanism was proposed. In order to enhance the bearing performance, the upright region and arc-like region should be designed to fail at the same time. For the rib named 0.333-S, the stress distributes uniformly and the critical load is 2.62 ; the upright region and arc-like region fail at the same time. For the rib named 0.5-S/R, the critical load is 1.465 , and it fails at the upright region, resulting in a reduction of 44%. The tent with ribs named 0.333-S shows better resistance performance against wind load, and the end ribs of this tent deform less. Its maximum displacement is 0.112 m, which is reduced by 65.8% compared with that of the original upright arch tent.
The existing large inflatable membrane structure is complex in structure and takes a long time to be extended. In this paper, an air-ribbed skeleton membrane structure is proposed to meet the requirement of camp and emergency tents needing to be set up quickly and easily. Ten single-arch air ribs are arranged side by side to support the tarpaulin, and wind ropes are added to the end and side faces of the tarpaulin to remain stable. The finite element model of the air-ribbed skeleton membrane structure is established to analyze the stress and the displacement of the membrane structure under combined wind and snow loads. The maximum displacement (439.4 mm) and maximum stress (29.94 MPa) are both within the safe standard. The stress and the displacement of the membrane structure in the wind load case is affected by the angle of the wind. The value of maximum stress and displacement at the wind angle of 90° are both lower than those at 0° and 45° in the wind load case. It is advisable to align the site layout of the membrane structure at the wind angle of 90°. The effect of the angle of wind ropes on the stress and displacement of the membrane structure is also studied. The maximum stress and displacement in the case when the angle of wind rope is 30° is smaller than those in the case when the angle of wind ropes is 45°. It is recommended that the wind rope should be laid at 30° to reinforce the membrane structure.
7 November 2024 in Separation Science and Technology