水泥混凝土路面损坏的原因及防治措施

水泥混凝土路面具有强度高、使用寿命长、稳定性好、不易变形等特点,在建设中广泛采用。但在行车荷载和环境因素的作用下会出现不同类型的损坏,本文据此有针对性地采取了防治措施,以避免水泥混凝土路面损坏。     

浅议精神损害赔偿的涵义

精神损害赔偿作为一项重要的民事法律制度，已在我国的司法实践中被广泛采用。但目前仍缺乏明确系统的法律规定，进一步完善我国的精神损害赔偿法律制度，已成当务之急。这要求我国必须结合司法实践，对精神损害赔偿的性质、适用主体、适用范围等问题、进行深入、全面的探讨和研究，正确认识该项法律制度的涵义，为正确适用精神损害赔偿，更好地维护民事主体的合法权益，打下坚实的基础。     

第二代小波包构造及发动机微弱损伤识别

针对航空发动机滚动轴承微弱损伤识别问题,设计了一种识别滚动轴承早期损伤的第二代小波包方法.构造了第二代小波包分解重构算法和第二代小波包算子计算方法;将滚动轴承振动信号进行第二代小波包分解,然后各个频带分解信号分别进行重构;利用希尔伯特变换解调分析各频带信号,得到对应频带信号的包络谱;计算各个频带中滚动轴承故障特征频率对应包络谱幅值的分贝值,提取各频带中故障特征频率对应分贝值的最大值,对滚动轴承早期损伤情况做出定量识别.仿真信号和试验信号分析表明,该识别方法结果可靠,能准确识别出滚动轴承早期损伤.      

空军移交修理企业应急作战条件下战场抢修组织体系建设研究

介绍了在现今条件下,空军移交修理企业通过建立高效能的军、企联合战场抢修领导机构和战场抢修办公室,组建一支由多个抢修分队构成,配备高素质复合型技能人才的飞机战场抢修队的情况。     

Modified micro-mechanics based multiscale model for progressive failure prediction of 2D twill woven composites

To consider fiber random distribution at the microscale for the multiscale model based on the micro-mechanics failure (MMF) theory, clustering method is used for the extraction of amplification factors. As the clustering method is a kind of unsupervised machine learning method, the elements with similar mechanical behavior under external loading can be included in a cluster automatically at the microscale. With this modification, the fiber random distribution model can be used for multiscale damage analysis in the framework of MMF theory. To validate the modified multiscale analysis method, progressive damage analysis of a kind of 2D twill woven composites is conducted based on different microscale models. The stress values for microscale models with fiber hexagonal and random distribution patterns are compared first. Much higher stress concentration is generated in the fiber random distribution model due to the smaller inter-fiber distance especially under longitudinal shear loading. The obtained cluster distribution results exhibit the characters of the stress distribution in the two microscale models. Thereafter, tensile and compressive responses of the 2D twill woven composite are predicted with the modified multiscale analysis method and accuracy of the method is verified through comparison with published experimental results. From the simulation results, it can be found that the matrix damage initiation from the model based on the fiber random distribution model is premature compared with that from the model based on the fiber hexagonal distribution model. Besides, under tensile loading, the damage all initiates from the fill tows and propagates to the wrap tows. However, under compressive loading, the matrix damage initiates from the wrap tows in the model based on the fiber random distribution model.     

V2500发动机反推平移罩分段线区域结构损伤浅析

V2500发动机反推平移罩由于大面积使用复合材料，且日常运行环境相对恶劣，长期使用后容易出现结构损伤。为对损伤情况有更深入的了解，结合运行经验，对反推平移罩分段线区域的结构损伤特点进行了分析和介绍。     

Fatigue life research and experimental verification of superalloy thin-walled structures subjected to thermal-acoustic loads

Rapid alternating stress is formed in structure subjected to harsh thermal-acoustic loads, which will affect fatigue performance and reduce fatigue life seriously. First, fatigue experiment of superalloy thin-walled structure was carried out to obtain fatigue damage location and failure time of the experiment specimen, and S-N curves of superalloy thin-walled structure at 723 K were fitted. Then, dynamic response simulation of superalloy thin-walled structure under the same load as experiment was implemented, and fatigue life was estimated based on the fatigue life prediction model which mainly included: improved rain-flow counting method, Morrow average stress model and Miner linear cumulative damage theory. Further, comparisons between simulation solutions and experimental results achieved a consistency, which verified the validity of the Fatigue Life Prediction Model (FLPM). Moreover, taking a rectangle plate as the analysis object, the distributions of Fain-low circulation blocks and damage levels of the structure were discussed respectively. Finally, current research indicates that in pre-buckling the structure is in softened area and fatigue life decreases with the increase of temperature; in post-buckling the structure is in hardened area and fatigue life increases with the increase of temperature within a certain range.     

基于Nastran/Patran对飞机蒙皮损伤修理技术的研究

针对民用飞机蒙皮常见的凹坑损伤,利用Nastran/Patran软件总结归纳了修理时补片厚度、大小、形状等主要修理工艺参数的变化对修理质量的影响,进而优化修理方案。     

基于兰彻斯特方程的防御作战效能分析

对防御作战的重要意义、目的和基本方法进行了分析总结,在此基础上,通过对兰彻斯特方程的毁伤系数进行分解和细化,建立了体现防御的兰彻斯特方程,给出了具体算例,并简要分析了其对平局条件、交战强度等方面的影响。     

配合间隙对涡轮叶片榫头/榫槽接触的影响

采用率相关晶体塑性滑移理论模型,考虑镍基单晶的晶体取向和涡轮盘/片配合间隙的影响,针对涡轮叶片榫头/榫槽的复杂接触状况,研究了温度梯度载荷和离心载荷作用下三种取向的接触应力和低周疲劳损伤。结果表明:当榫头/榫槽的配合间隙小于3.7μm时,榫头/榫槽的接触应力随间隙值突变比较明显;而间隙值大于5.4μm时影响较小。接触应力和低周疲劳寿命对第一齿间隙值比较敏感,随间隙值的波动变化范围较大;第二齿的间隙对接触应力影响也较大,但对疲劳寿命的影响只在较小间隙值下较为明显。晶体取向对榫头/榫槽接触低周疲劳寿命有比较显著的影响,表现出明显的疲劳性能各向异性。