경량재료를 이용한 항공기 과주방지 포장의 거동분석

Abstract

We have carried out the laboratory tests for several lightweight materials on their strength behavior characteristics through which we have chosen the perlite concrete as the most suitable lightweight material for the pavement to prevent the aircraft from overrunning. We have also analyzed the behavior of the lightweight pavement made of the perlite concrete for the aircraft model such as B707-320, B737-800, and B747-400 to secure their safety. The tests are as follows. The perlite concrete shows that the more it contains the perlite in the mixture of cement and perlite, the lower it gives the value of both unit weight and peak strength, and the less the shear stress decrease in the range of plasticity. We have carried out both the laboratory penetration test on the specimens and the on-site vehicle-wheel penetration test on the real pavements which are maid of the perlite concrete with cement : perlite mixing rate of 1 : 8. The results of the both penetration tests have shown to be similar values for their penetration rates, such as about 80% and 78%, respectively. We have studied the relationship of the arresting distance and the penetration depth of the wheels of the aircraft onto the lightweight pavement according to the types of aircraft by using the ARRESTOR's 2-dimensional numerical analysis program, from which we have found it the most suitable values in design that the arresting distance was 128.5m and that the penetration depth was 0.4m when the penetration strength of the pavement was 500kPa for the case of B737-800, and the same was the arresting distance and the penetration depth, 154.4m and 0.415m, respectively when the penetration strength was 600 kPa for B747-320, and also the most suitable values was the arresting distance and the penetration depth, 179.3m and 0.442m, respectively when the penetration strength was 700 kPa for B747-400. When the strength of the lightweight pavement is relatively high compared to the weight of aircraft, the penetration depth of the wheels of the aircraft is calculated as being relatively low, and which causes the arresting distance to be evaluated as being relatively long. And also when the strength of the pavement is relatively small compared to the airplane's weight, the trend that the arresting distance gets longer appears due to lack of drag force against the aircraft's driving force, even though the sufficient penetration depth occurs. In addition, it has been analyzed that the necessary penetration depth of the wheels of the aircraft for the protection against the aircraft overrun should need more than minimum depth of 60% to the whole thickness of the pavement.