拉伸速率对CMDB力学性能的影响

采用单向拉伸实验研究了不同拉伸速率(2～200 mm·min-1)条件下CMDB推进剂的应力——应变曲线变化规律,并得到了不同温度条件下(-50～50℃)拉伸速率对CMDB推进剂最大拉伸强度和最大伸长率的影响。结果表明:CMDB推进剂的应力——应变曲线大体可分为3个阶段;同样拉伸速率条件下,CMDB推进剂的最大拉伸强度和最大伸长率随温度升高分别减小和增大;同样温度条件下,最大拉伸强度和最大伸长率随拉伸速率增加分别增大和减小;CMDB推进剂的最大拉伸强度、最大伸长率与拉伸速率存在较好的幂函数关系。     

低温动态加载下三组元HTPB复合固体推进剂的失效判据

基于三组元端羟基聚丁二烯(HTPB)复合固体推进剂在不同热加速老化时间(0,32,74,98 d)和不同加载温度(-50,-40,-30,-20,25℃)以及不同应变率(0.40,4.00,14.29,42.86,63 s~(-1))条件下的单轴和准双轴拉伸力学性能实验以及细观损伤观测实验,分析了加载条件对推进剂初始弹性模量,强度和最大伸长率的影响规律,确定了单轴和准双轴拉伸加载下推进剂的失效判据。结果表明:动态单轴加载下推进剂易因拉伸应力作用而失效,且热老化后推进剂抵抗破坏的能力降低,拉伸时的最大伸长率可选为失效判据。其次,拉压强度比更能反映推进剂的动态单轴拉压差异性,室温和低温条件下,其数值分别接近于0.4和0.2～0.3。动态准双轴拉伸加载下,推进剂的最大伸长率较单轴加载时明显降低,降低的幅度随热老化时间增长而增大,且温度越低,降低越明显。未老化推进剂在准双轴拉伸加载下的最大伸长率约为单轴拉伸条件下数值的60%～85%,而老化后约为40%～60%。低温高应变率条件下,最大伸长率不受应力状态和应变率变化的影响。动态双轴拉伸条件下的最大伸长率可选为相应加载下推进剂的失效判据以及点火建压条件下战术导弹固体火箭发动机(SRM)药柱结构完整性分析的判据,其数值可结合主曲线和老化模型确定。     

爆胶棉对浇铸高能少烟CMDB推进剂工艺和力学性能影响

采用HAAKE流变仪和单轴拉伸试验,分别研究了爆胶棉(PNC)对浇铸高能改性双基推进剂(CMDB)推进剂工艺与力学性能的影响,并用B.S.T公式计算了含PNC的推进剂的物理交联密度。结果表明,在PNC含量为0.1%~0.5%的范围内,CMDB推进剂药浆为典型的假塑性流体;其粘度-剪切速率曲线均符合Ostwald de Waele方程;PNC含量增大,CMDB推进剂药浆的表观粘度(剪切速率为1 s-1)增大,其流平性能逐渐变差,但仍具有较长的适用期,可满足推进剂工程化的工艺要求。研究还表明,在CMDB推进剂中适量增加PNC含量,可提高推进剂中的物理交联密度,改善推进剂的密实性、连续性以及粘结剂基体对填料的包覆效果,提高推进剂的高、低温(50℃和20℃)抗拉强度。     

NC/NG/AP/Al复合改性双基推进剂力学性能研究

研究了硝化棉含量、固体组分粒度级配和固化剂对NC/NG/AP/Al复合改性双基(CMDB)推进剂的力学性能的影响。结果表明,随NC含量的降低,CMDB推进剂 20℃和 50℃下的抗拉强度降低,硝化棉的质量百分含量为20%时,推进剂的伸长率出现最大值;固体组分的粒度级配对CMDB推进剂的力学性能有较大的影响,AP(96.8μm)、RDX(44.9μm)和Al(10.8μm)质量百分含量的比值为1∶1∶1时,该推进剂力学性能为最佳;硝化棉含量较少的CMDB推进剂体系,进行适度交联固化可在一定程度上提高抗拉强度,明显提高推进剂的伸长率。     

浇铸型高能CMDB推进剂的力学性能

研究了硝化棉种类和含量、高氯酸铵粒径,以及双基球和黑索今含量等对复合改性双基(CMDB)推进剂力学性能的影响。结果表明,随着含氮量12.0%的NC的降低,CMDB推进剂20℃和50℃下的拉伸强度和延伸率均显著降低。在CMDB推进剂中添加适量含氮量13.0%的NC和12.6%的NC均有助于提高推进剂拉伸强度;含氮量13.0%的NC不利于改善推进剂的延伸率;而含氮量12.6%的NC有助于提高推进剂的低温延伸率,但对推进剂高温延伸率影响不显著。在CMDB推进剂中添加适量的双基球对提高推进剂的拉伸强度和延伸率均有利。AP的粒径对CMDB推进剂力学性能影响显著,小粒径的AP有利于提高推进剂的拉伸强度,而大粒径的AP有利于改善推进剂的延伸率。随着RDX取代AP量的逐渐增大,CMDB推进剂在高温和常温下的拉伸强度先增大后减小,而延伸率先增减小后增大。     

NEPE推进剂无损型贮存寿命预估

为了实现对硝酸酯增塑聚醚(NEPE)推进剂药柱贮存寿命进行预估时的测量无损性,通过对施加10％定压缩应变的NEPE推进剂进行高温热加速老化实验、气体含量监测实验、单向拉伸力学性能实验,基于相关性分析和寿命预估模型,提出了一种以特征气体含量变化为基础数据的无损型寿命预估模型.结果表明,NEPE推进剂贮存老化过程中,CO气...     

结构试验器固体推进剂装药低温加速老化试验研究

采用低温加速老化试验的方法,依据GJB770B-2005火药试验方法,测试了6%、9%、12%和15%四种不同应变水平的结构试验器在单轴拉伸条件下的最大拉伸强度σm和最大伸长率εm,考察了四种结构试验器中装药推进剂在低温(-28℃)下贮存性能随老化时间的变化趋势。结果表明:在低温应力应变情况下结构试验器中推进剂老化的主要原因是应力损伤。动态力学分析(DMA)试验(频率1 Hz,振幅20μm,测试温度范围-100~80℃,升温速率为3℃·min-1)证实推进剂确已发生损伤。常温拉伸(拉伸速度100 mm·min-1,测试温度(23±2)℃)情况下,推进剂σm逐渐升高,15%应变的结构试验器经过19周低温老化后,σm(0.96 MPa)与初始值(0.74 MPa)相比增加了近30%,εm基本在初始值附近波动;低温快速拉伸(拉伸速度500 mm·min-1,测试温度(-55±2)℃情况下老化后期推进剂σm升高,εm明显下降,15%应变的结构试验器经过19周低温老化后,σm(4.18 MPa)与初始值(3.77 MPa)相比增加了约11%,εm(26.8%)与初始值(37.6%)相比降低近29%。根据试验现象初步分析推进剂在低温应力情况下的老化机理可能是应力/应变作用下的物理损伤,包括网络内聚损伤和固体颗粒与粘合剂界面"脱湿"。     

高低温循环下HTPB推进剂力学性能规律研究

为了获得高低温循环下HTPB推进剂的力学性能变化情况,通过高低温循环实验(又称温度渐变实验)和单向拉伸实验,对HTPB推进剂高低温循环力学性能规律进行了研究.实验结果表明:高低温循环下HTPB推进剂的最大抗拉强度和最大延伸率都随着循环周期数的增加而降低,这与热氧老化下的力学性能变化规律不同.最后,运用灰色理论预测了该实验条件下HTPB推进剂失效时的高低温循环周期数.     

配方对富燃复合推进剂力学性能影响的实验研究（英）

为实验研究推进剂配方对基于端羟基聚丁二烯粘结剂(HTPB)/过氯酸铵氧化剂(AP)/铝粉燃料(Al)的富燃复合推进剂力学性能的影响。综合混合、浇铸和固化影响因素,制备了11种不同推进剂试样10 kg,并在25 ℃下采用Zwick试验机以50 mm·min^-1的速率对标准JANNAF试件进行了测试。结果表明,当粘结剂的含量从74.5%减小到34.5%、以AP和Al替代时,推进剂的应变减小,抗拉强度、杨氏模量和硬度增大。AP的颗粒尺寸和含量对推进剂的力学性能有影响,AP细颗粒可充当了活性的填充物并增强复合推进剂的力学性能,当AP颗粒的平均直径从55.9 μm减小到9 μm时,推进剂的抗拉强度、杨氏模量和硬度增大,应变减小,表明该类富燃复合推进剂力学性能主要受到粘结剂和AP平均颗粒尺寸的影响。     

复合改性双基推进剂黏弹性-黏塑性-黏损伤本构模型研究

为描述复合改性双基(CMDB)推进剂复杂的力学性能,推导出黏弹性-黏塑性-黏损伤本构模型。进行一系列蠕变-回复试验,获得了本构模型参数。通过不同应力水平和不同加载时间下的蠕变-回复试验和恒加载率-回复试验,验证了本构模型的有效性。结果表明：黏弹性-黏塑性-黏损伤本构模型能够预测CMDB推进剂的蠕变-回复响应和恒加载率-回复响应;与黏弹性-黏塑性本构模型相比,黏弹性-黏塑性-黏损伤模型对CMDB推进剂力学性能的预测能力明显提高;损伤变量随着应变增大,在经过缓慢增大和快速增大后逐渐趋于稳定,应变变化越慢,损伤变量越大,黏弹性-黏塑性-黏损伤模型和黏弹性-黏塑性模型的预测结果差别就越大。     

Method for Measuring Velocity of Warhead Fragments Based on Photoelectric Detection

For measuring velocity and impacting position of single fragment of warhead, a non-contact measuring method is proposed, in which a six-light-screen array, a position indicator, a multi-channel chronograph and a computer are used.The principle of measurement is described. The key device of the system is a light screen array sensor which consists of six light screens allocated with certain geometrical parameters. When the fragment flies through the light screen array, the time of passing through each of the screens is recorded by the multi-channel chronograph. According to the time data and the geometrical parameters of the array, the velocity vector and the location of the fragment can be calculated immediately. The presented method can be used to locate the fragment and to measure the real velocity on its flying direction. It can also be used to measure the velocity of a fragment swarm after the system is engineered further.     

数码电子雷管中影响点火头性能因素分析

阐述了数码电子雷管中,点火药剂细结晶三硝基间苯二酚铅（LTNR）的制备工艺;从点火药剂的种类、加入黏合剂的质量分数、桥丝直径、点火头的电阻值、防潮漆的蘸涂等方面对点火头性能的影响因素进行了探讨;通过震动试验、并联起爆试验、延期精度检测与考核,试验结果表明：一次性合成的细结晶LTNR是制造数码电子雷管点火头较为理想的点火药剂,按技术要求生产的点火头性能指标能够满足行业标准要求。     

Open Rule-setting System Applied to Conceptual Design of Engines

Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.     

Design and Implementation of One Missile Visual Simulation System Based on OpenGL

The implementation of a missile＇s visual simulation system is explained that is developed with OpenGL（open graphic library） and the flight path and flight carriage in different stages of the missile are displayed. The establishment problems of the 3D scene are circumstantiated including the construction and redeployment of the model, creation of the virtual scene, setting of the multi-viewports and multi-windows etc. The missile＇s data driver, system flow, the modules and their mutual relations of the missile visual simulation system are discussed. The missile flight simulation results and effect of the scenes are given.     

Research on Linux Network Device Driver

By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux （kernel version 2.6.11 ） is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.     

Dynamic Encryption Technology in Ad-hoc Networks

A new dynamic encryption application in ad-hoc networks is proposed. The advantages of this method are its being able to use the previous ciphertext as a seed of a new encryption process, rendering the encryption process effective in all communication process by continuous dynamic key generation together with synchronization, and its capability to cut back on system bandages to a greater extent, which is valuable for the ad-hoc circumstance. In addition, the rationality and effectiveness of this novel encryption method have been verified by the test results.     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

An Experimental Study on Electro Chemical Machining of Microelectrode

Puts forward a new method in machining microelectrode by electro chemical machining （ECM） and plastic deformed theory. The procedure of this method is to machine the microelectrode according to the basic rule of ECM theory at first. Then, with the change of ECM machining parameters, one of the microelectrode ends is exerted by a load. As a result, the elastic and plastic deformation is produced at the machining section and the microelectrode diameter is reduced. It has been proved that the proposed method can determine the optimum machining parameters to machine the microelectrode of Cu.     

Unscented Kalman Filter for Autonomous Warship Attitude Determination

To address a problem of autonomous attitude determination algorithm using gravitational field and geomagnetic field observation, a new recursive optimization autonomous attitude estimation algorithm is proposed. The algorithm is based on unscented Kalman fiher(UKF), and can synchronously provide the attitude rate information. The simulated results show that the measurement precision of the method could be increased by 2 times compared to that of the common methods.     

Error Coefficient Estimation of Inertial Platformin Its Calibration

The error coefficient estimation of inertial platform in the course of its consecutive ground calibration is studiedA separate-bias algorithm is adopted to estimate the error parameters effectively. The ill-conditioning problem of the equation solution caused by the huge state dimension is also resolved. And the simulation result shows its validity.