Simulation And Experimental Study On Ramjet Airdrop Airbag Cushion Performance

Airdrop is very important to the delivery of troops and materiel supply mode. Airdropequipment is easily damaged when subjected to an instant impact, so protective measuresshould be taken when landing, and airbag is widely used because of its light weight, simplestructure, good performance and so on. However, the current study of the airdrop airbagcushion technology is still in its early stage, and there is still a big gap compared with somedeveloped countries. Researching better performance, more efficient landing cushion airbagsystem is a hot in airdrop technology field.In this paper, it designs the ramjet airdrop airbag in aspect of shape, airbag materials, theinlet structure and vent area and so on. The airbag collects gas automatically from the bottominlet relying on the falling speed, carrying no high-pressure gas cylinders or gas generator sets,which can greatly reduce the airdrop system weight. It simulates the airbag landing processbased on ANSYS/LS-DYNA software, and analyses the airbag shape and stress changeduring the process, the change of displacement，velocity and acceleration of the airdropequipment as well as the working state of the airbag. To test the design idea of this paper andthe simulation results, the kind of drop test is carried on, divided into three groups of contrasttest, recording and analyzing the test results, compared with the simulation results.The simulation results shows that almost no rebound occurs on the airbag, the maximumimpact landing equipment overload is17.9g, less than the permitted maximum overload20g,so the airbag meets buffer requirements; the airbag stress cloud shows the part where thelargest stress occurs, the airbag pressure change curve shows the maximum gas pressure is1.98×105Pa during the landing process. In practical engineering design, attention should bepaid to the larger portion of airbag stress, and prevent the balloon burst due to stress. The test results show that: the ramjet airdrop airbag can realize the function of automatic filling, andthe airbag has good buffer effect.