复合材料层合结构频率约束的可靠性优化设计(英文)

The reliability based optimization （RBO） issue of composite laminates trader fundamental frequency constraint is studied. Considering the tmcertainties of material properties, the frequency constraint reliability of the structure is evaluated by the combination of response surface method （RSM） and finite element method. An optimization algorithm is developed based on the mechanism of laminate frequency characteristics, to optimize the laminate in terms of the ply amount and orientation angles. Numerical examples of composite laminates and cylindrical shell illustrate the advantages of the present optimization algorithm on the efficiency and applicability respects. The optimal solutions of RBO are obviously different from the deterministic optimization results, and the necessity of considering material property uncertainties in the composite structural frequency constraint optimization is revealed.     

固体火箭发动机纤维缠绕壳体贮存性能试验研究

通过设计、制作Ф200缩比模拟试验件,对缩比模拟试验件进行加速老化,然后对加速老化试验前后的试验件进行外气密试验、轴压破坏试验、内压爆破试验,探究复合材料壳体的贮存使用性能。     

构建实例库的参数模型及其应用

通过分析系统模型和IDEFO模型,提出了实例参数模型,即将切削系统的各组成参量分成4类:非控制参量,过程参量,控制参量和输出参量并以此提出了实例库的构建过程.最后根据提出的参数模型,建立了高速切削数据库系统.     

轴承钢等离子体基离子注碳复合改性层化学结构的研究

通过激光Ｒａｍａｎ光谱、Ｘ射线光电子谱以及电阻和显微硬度的测试，研究了ＧＣｒ１５钢及镀钛ＧＣｒ１５钢试样经乙等离子基离子注入所得表面改性层的化学结构。     

基于模糊逻辑推理的船舶并联气电混合动力系统能量最优分配研究

针对内河船舶工况启停变化频繁导致瞬态动力性较差、动态响应较慢等问题，提出并联气电混合动力系统改进方案，利用模糊逻辑推理方法来提升动力响应性能。以某内河拖船为研究对象进行混合动力系统参数匹配设计，通过对系统关键参数设计切换规则，建立基于逻辑门限的能量管理控制策略；为进一步优化逻辑门限方法主观设定边界阈值不可调节问题，提出基于“模糊逻辑推理+动态协调”能量最优分配策略。通过最优设计相关试验验证管理策略，结果表明：采用基于模糊逻辑推理的能量管理策略能使天然气发动机的平均负荷提升37.86%，平均效率提高2.74%，动态响应时间缩短44.45%。     

纳米孔超级绝热材料研究现状及进展

纳米孔超级绝热材料是一种新型高效隔热材料,具有轻质、耐高温、孔隙率高、导热率低等优点,
目前已成为保温隔热材料领域研究的热点,其中最具代表性的是气凝胶隔热材料和纳米粉末基复合隔热材料。
本文对这两种隔热材料的研究现状进行了综述,并对纳米孔超级绝热材料发展前景进行了展望。     

美国地下领域无人系统发展现状及启示

随着科学技术的高速发展,地下领域(如天然洞穴网络、人造隧道和城市地下环境等)逐渐成为人类研究的热点,利用无人系统在地下等复杂场景执行探索、搜索与搜救等任务仍面临着许多挑战.深入分析了美国地下领域无人系统技术发展的模式框架,梳理了快速轻量自主、机械天线和地下挑战赛等DARPA典型研发项目的 研究目标与现状,提炼出地下领域无人系统需要解决的关键技术,在此基础上归纳总结了美国地下领域无人系统的发展趋势.最后,结合国内发展情况提出了地下领域无人系统的发展启示.     

纳米孔硅质绝热材料

介绍了纳米孔硅质绝热材料的绝热机理及发展概况，同时简要介绍了其生产工艺，并对其主要物化性能、热学性能及其它应用特点作了较为详细的说明。     

On the evidential reasoning rule for dependent evidence combination

Evidential Reasoning (ER) rule, which can combine multiple pieces of independent evidence conjunctively, is widely applied in multiple attribute decision analysis. However, the assumption of independence among evidence is often not satisfied, resulting in ER rule inapplicable. In this paper, an Evidential Reasoning rule for Dependent Evidence combination (ERr-DE) is developed. Firstly, the aggregation sequence of multiple pieces of evidence is determined according to evidence reliability. On this basis, a calculation method of evidence Relative Total Dependence Coefficient (RTDC) is proposed using the distance correlation method. Secondly, as a discounting factor, RTDC is introduced into the ER rule framework, and the ERr-DE model is formulated. The aggregation process of two pieces of dependent evidence by ERr-DE is investigated, which is then generalized to aggregate multiple pieces of non-independent evidence. Thirdly, sensitivity analysis is carried out to investigate the relationship between the model output and the RTDC. The properties of sensitivity coefficient are explored and mathematically proofed. The conjunctive probabilistic reasoning process of ERr-DE and the properties of sensitivity coefficient are verified by two numerical examples respectively. Finally, the practical application of the ERr-DE is validated by a case study on the performance assessment of satellite turntable system.     

A novel combination belief rule base model for mechanical equipment fault diagnosis

Due to the excellent performance in complex systems modeling under small samples and uncertainty, Belief Rule Base(BRB) expert system has been widely applied in fault diagnosis. However, the fault diagnosis process for complex mechanical equipment normally needs multiple attributes, which can lead to the rule number explosion problem in BRB, and limit the efficiency and accuracy. To solve this problem, a novel Combination Belief Rule Base(C-BRB) model based on Directed Acyclic Graph(DAG) structu...