热电池电压异常波动技术分析及改进

分析了试验过程中热电池电压异常波动的原因,最终给出了问题的解决措施。该问题的解决对后续热电池的结构设计及工艺控制具有重要的指导意义。     

全模颤振双索悬挂系统刚体模态频率研究

研究绳系结构和绳索预紧力对全模颤振双索悬挂系统刚体模态频率的影响。首先，基于绳索并联机构理论，对双索悬挂系统进行静力学建模，引入加权矩阵，推导了双索悬挂系统静刚度模型；其次，建立双索悬挂系统无阻尼振荡方程，分析双索悬挂系统刚体模态频率变化规律；进而，搭建了双索悬挂系统地面样机，开展系统模态频率测试试验，研究系统刚体模态频率的影响因素及其变化规律；最后，参考试验结果修正所建数学模型。结果表明，随着绳索预紧力的增加，系统刚体模态频率呈上升趋势，但各阶刚体模态的固有频率上升速率不同，平动模态的固有频率受绳索预紧力影响比转动模态小得多；在转动模态方面，滚转模态的固有频率最大且上升快；在平动模态方面，升沉模态的固有频率大于横侧滑模态的固有频率；双索经过的机身前后滑轮与飞机模型质心之间的相对位置变化会不同程度地影响支撑系统俯仰模态、偏航模态的固有频率，但几乎不影响其滚转模态的固有频率。研究发现，通过控制悬挂绳索预紧力的大小，合理设计机身上的滑轮安装位置，能够有效降低双索悬挂系统刚体模态频率。研究结果对于优化设计全模颤振双索悬挂系统具有指导意义。     

Sensitivity analysis for probabilistic anti-resonance design of aeronautical hydraulic pipelines

In an uncertainty scheme, reliability and global sensitivity analysis is studied in this work, to provide helpful information for probabilistic anti-resonance design of vibration systems.Discussions show that the resonance failure problem can be viewed as a series system, in which input uncertainties are modeled by random variables. In order to quantitatively measure the contributions of input variables to the system reliability, a global sensitivity index is proposed, the properties of which are also discussed. Then the proposed index is tested with an aeronautical hydraulic pipeline system, which is under the excitation of pump vibration and at a risk of resonance failure. Sensitivity results under different failure criteria and variation coefficients are obtained and studied, from which significant and insignificant input variables can be identified.The proposed method provides a relatively new insight for anti-resonance design of engineering structures.     

装备激励约束定价模式机理对比分析与设计

激励约束定价模式能够极大调动承包商积极性，是控制装备成本的一种重要方法。通过深入分析美军激励约束定价模式和我军激励约束定价模式的设计机理，提出了承包商的期望利润和军方期望价格的计算方法，并通过对比不同定价模式的特点，在借鉴2种激励约束定价模式优点基础上，设计了一种新的激励约束定价策略，提出了指导装备激励约束定价模式改革的对策建议。最后，通过算例对本文方法进行了解释，同时验证了本文方法的有效性。     

Influence of pre-tension on ballistic impact performance of multi-layer Kevlar 49 woven fabrics for gas turbine engine containment systems

In this paper, ballistic impact tests on wrapped multi-layer Kevlar 49 woven fabric systems were carried out with a flat blade projectile to investigate the impact response during a fan blade out event. The influences of the number of Kevlar layers and pre-tension were discussed particularly. Test results were used to analyze failure modes and energy absorption characteristics of multi-ply Kevlar fabrics. Results show that there are two kinds of impact damage for fabrics: global deformation mainly involving stretching of yarns in the impact region and fabric wrinkle from both sides to the impact zone, and local damage characterized by yarn fracture, yarn pull-out, and yarn unraveling. The energy absorption capability of Kevlar 49 woven fabrics improves with the number of fabric layers. The energy absorbed by multi-layer fabrics increases slightly at the beginning and then decreases substantially with pre-tension. The work in this paper can provide guidance for designing light-weight multi-layer fabrics containment systems.     

激光动态液位测量技术研究

如今,运载火箭大量使用液氧、煤油等液体推进剂,其液位测量技术主要有浮子式、激光式、电容式、雷达式等。介绍并实现了一种激光液位测量系统,该系统体积小、功耗低,可适应多种测量环境,能满足航天燃料液位测量高精度、高动态、连续稳定测量的要求。系统利用相位式激光测距技术,通过测量激光回波信号的相位延迟,计算激光光程从而得到距离数据并通过客户端进行直观展示和数据存储。系统最大测量距离可达100 m,精度为±1 mm。该系统为非接触测量,耐腐蚀,通过加入反射板可实现透明、非透明液体测量。