疲劳和磨损耦合作用下枪炮身管健康监测研究

When a gun fires, fatigue and wear do damage to gun barrel and cause its life termination, especially endanger firing safety. It is an urgent problem that gun barrel safety design and evaluation should be solved shortly under complicated loading conditions and service environment. Barrel health monitoring is an important means to certify the safe service when the traditional life prediction methods could not accurately assess the failure time of gun barrel. In this project, the mapping relationship between inherent affecting factors of barrel health (failure mechanism of fatigue-wear interaction) and external characteristic parameters (local strain on exterior surface of barrel) is investigated thoroughly. In order to overcome the deficiency of neglecting effects of strain rate on gun barrel in current fatigue life testing method, a gas gun-based impact fatigue life testing method and a high speed friction and wear testing method are developed. Primary experimental results by using this method are in accordance with those of actual firing by Type 95 Automatic Rifle. On the basis of exploring the effects of all kinds of factors on the strain of barrel exterior surface when projectile interacts with gun during firing process, the mechanism of fatigue crack formation, propagation and barrel rupture is revealed under high strain rate and fatigue-wear interaction. Barrel health monitoring method based on local strain as damage characteristic parameter is developed and prediction model of gun barrel residual life is established. The results have great significance and value in design, experiment, usage and maintenance of gun.

枪炮发射时，疲劳和磨损造成身管损伤并致其寿命终止，甚至危及发射安全性。复杂载荷工况和使用环境下的身管安全性设计与评估是亟待解决的问题。鉴于传统的寿命预测技术不能准确预测身管失效时间，身管健康监测是确保枪炮安全服役的重要手段。本项目将系统研究身管健康状态的内在影响因素（疲劳和磨损耦合失效机制）与其外在特征参数（身管外壁局部应变）之间的映射关系。针对现有身管疲劳寿命试验未考虑应变率等因素影响的突出缺陷，发展基于气炮发射的身管冲击疲劳寿命试验和高速摩擦磨损试验方法（采用该方法的预试验结果与95式自动步枪实弹射击试验结果吻合），尽力探明各种因素对弹-炮相互作用过程中身管外壁应变影响规律，深入揭示在高应变率和耦合失效机制下的身管疲劳裂纹形成、扩展直至断裂机理，进而发展以局部应变为损伤特征参数的健康监测方法，并构建身管剩余寿命预测模型。研究成果对枪炮设计、试验、使用和维护具有重要的理论意义和应用价值。

枪炮发射时，身管内膛因疲劳与磨损耦合作用而受损伤，身管健康随射弹发数增加而不断劣化，直至身管寿命终止，甚至会发生膛炸、胀膛等发射安全性事故，危及人员安全。准确评估身管健康和预测剩余寿命对保证发射安全性具有重要意义，也是各国竞相攻关解决的重要理论与技术难题。研究内容和取得的主要成果包括：.（1）建立了基于应变的枪炮身管健康监测方法。全面分析了传统基于尺寸、图像、温度和初速变化的身管寿命评定方法存在的缺陷，首次提出了以发射时身管外壁面应变为特征参数的身管健康监测新方法，从理论上揭示了应变与弹丸-身管-发射药系统的内在映射关系。.（2）设计了身管健康监测原理模拟验证试验装置。研制了弹丸-身管机械相互作用和液压疲劳两种验证试验装置，分别包括了准静态（低应变率）和动态冲击（高应变率）加载两种方式。.（3）揭示了弹丸-身管机械相互作用的特点规律。准静态和动态冲击试验结果表明，在内弹道时期的不同阶段，应变率效应、应变强化效应和热效应对弹丸-身管相互作用起着重要的控制作用。身管外壁面应变随射弹发数的增加呈不断下降趋势，反映了身管内膛损伤积累条件下弹丸-身管相互作用弱化的本质规律。.（4）探明了内压循环载荷下身管疲劳损伤机制。液压疲劳试验结果显示，身管外壁面应变在管件疲劳寿命周期中的演变规律，与身管在循环载荷作用下的疲劳损伤相对应，即裂纹的稳定扩展、快速扩展以及身管失稳断裂。.（5）提出了身管等离子淬火延寿方法。等离子淬火试验研究结果揭示了炮钢表层淬火后的微结构形态及其伴随的力学性能变化，对提高身管内膛抗磨损、抗疲劳性能进而延长其服役寿命有重要意义。