Study on allocation and realization method of helicopter vulnerability index

Peng Hou,Chen Tian,Guangran Zu,Zhiwei Chen,Yang Pei,Junqiang Ai

doi:10.1051/jnwpu/20213930593

Abstract

To reduce the vulnerability of attack helicopters under fragment/projectile strikes, the method of assigning vulnerability index from the whole aircraft to critical components under single and multiple attacks is mainly studied. Under a single strike, the system components in the same direction are divided into three situations: no component overlap, nonredundant model with component overlap and redundant model with component overlap. Two index allocation methods based on the ratio of the presented area of the critical components and the ratio of the vulnerability assessment results of the critical components are proposed. The system components are divided into redundant components and non-redundant components, and an index allocation method based on the proportion of critical components' vulnerability results is proposed under multiple strikes. On this basis, combining with the vulnerability reduction measures of attack helicopters, the vulnerability index requirements of corresponding components are achieved through iterative analysis. Finally, the AH-64D helicopter is subjected to simulation tests under single and multiple strikes, and the vulnerability indexes of B-level and C-level are assigned, which verified the feasibility of the method.

Highlights

The system components in the same direction are divided into three situations: no component overlap, nonredundant model with component overlap and redundant model with component overlap
Two index allocation methods based on the ratio of the presented area of the critical components and the ratio of the vul⁃ nerability assessment results of the critical components are proposed
The system components are divided into redun⁃ dant components and non⁃redundant components, and an index allocation method based on the proportion of critical components' vulnerability results is proposed under multiple strikes

Summary

Introduction

Robinson 等[9] 采用实验研究了弹道损伤对直升机旋翼翼型气动性能的影响。张媛等[10] 和刘刚等[11] 研究了冲击波与破片对武装直升机旋翼和结构联合作用的杀伤效应与杀伤因素。王志军等[12] 分析了 PELE 弹丸对武装直升机关键部件驾驶舱和发动机舱的杀伤效能。这些文献详细分析了典型杀伤元对武装直升机关键部件的杀伤,建立了相应的评估模型,但是缺少关键部件杀伤对直升机整机易损性影响的进一步分析。在直升机易损性减缩设计方面, 09 财政年美国空军在易损性减缩领域提出针对油箱防燃抑爆、无油区分析与水锤效应缓解、抗弹、结构与材料等方面的易损性减缩措施[13] 。 Coniglio 等[14] 分析研究了直升机易损性设计的关键区域以及这些区域对应的易损性减缩措施。 Wisniewski[15] 从装甲防护角度研究了直升机在遭遇 RPG⁃7 时的防护效能。武岳等[7] 综述了国内外武装直升机复合防弹装甲的发展状况,总结了直升机复合防弹装甲未来的发展需求。这些文献对直升机关键部件的易损性减缩原则、方法以及具体的减缩措施进行了详细研究。但易损性减缩的应用需与易损性指标相 (15 432.1mf ) c3( secθ) c4(3.280 84Vz) c5 (6) mr = mf - 6.48 × 10c6[61 023.75hAf ] c7· (15 432.1mf ) c8( secθ) c9(3.280 84Vz) c10 (7) 式中: Vz,Vr 分别为弹丸着靶速度和穿透靶板后的剩余速度, 单位为 m / s;h 为靶板材料厚度, 单位为 m;Af 为破片的碰撞面积, 单位为 m2;mf,mr 分别为弹丸着靶时的质量和穿透靶板后的剩余质量,单位 g;θ 为弹道射线与命中面元法向矢量的夹角;c1 ~ c10 为与靶板相关的材料参数[24] 。伤概率。 Pki 为 3 种情况中第 i 个部件 / 重叠区域的杀伤概率,Pkj1,Pkj2 分别为双余度部件的杀伤概率。如图 8 所示,打击方向 P 相对于目标的方位角 A 和俯仰角 E 的具体设置如表 1 所示。

Results

Conclusion