Stress Analysis of Composite Double Lead Spiral in 20mm Universal Ammunition Loading System

20mm 범용탄약적재장비의 복합재 이중리드나선구조 설계

Abstract

This paper addresses the stress analysis and design of composite double lead spiral which is boarded in 20mm universal ammunition drum by finite element method. The spiral system is very important to transfer the ammunition in stable and reliable manners for aircraft. Some verifications are done to check the possibility of composite application in spiral system. The design variables, stacking sequence and fiber orientation angles, are investigated for reliable design for practical design. The Tsai-Wu failure theory is applied to see the safety of the spiral structure. The design result is suggested to manufacture the double lead spiral part.

본 연구에서는 20mm 범용탄약적재장비의 운행 시 탄약의 운동에 관여하는 이중리드나선의 설계를 위해 이중리드나선에 발생하는 응력과 변형에 대하여 ABAQUS 프로그램을 이용해서 해석한다. 해석을 위해 복합재를 적용한 나선형 물체의 회전 시 발생하는 응력 해석의 타당성을 확인한다. 이중리드나선의 재료를 일반 금속과 복합재로 적용하여 해석하고 모델을 복합재료로 대체 하였을 때 이점을 제시한다. 또한 복합재료의 적층각과 적층순서, 회전속도의 변경 시에 발생하는 응력과 변형을 예측하고, Tsai-Wu failure 이론에 해석결과를 적용하여 파손을 확인하며. 탄약적재시 스텝의 개발을 위한 복합재 이중나선구조의 설계결과를 제시한다.

Fig. 1. Figure of 20mm universal ammunition drum

Fig. 2. Drum assembly including ammunition

Fig. 3. Boundary conditions of reference model

Fig. 4. Basic fiber stacking direction

Fig. 5. 4-cases to find stress along radius

Fig. 6. Radial and tangential stress along radius in 4 cases

Fig. 7. Mesh of drum assembly

Fig. 8. Boundary conditions of model

Fig. 9. Load conditions of model

Fig. 10. Principal stress distributions of basic model

Fig. 11. Stress and displacement through path line

Fig. 12. Radial and tangential stress along radius in 4-cases

Fig. 13. Comparison between standard model and each case

Table 1. Values of shaft & lead spiral model

Table 2. Analysis results of reference model

Table 3. Material properties of composite

Table 4. Values of drum assembly model

Table 5. Material properties of aluminum (2014-T6)

Table 6. Engineering strength of composite material

Table 7. Comparison of aluminum and composite material

Table 8. Failure of each ply

Table 9. Maximum results of each case with respect to the change of stacking sequence

Table 10. Changes in principal stress, displacement and failure index with respect to rotating velocity