SRM 纤维缠绕壳体的蒙特卡罗随机有限元分析

采用蒙特卡罗随机有限元方法，结合复合材料壳体力学、纤维缠绕理论等知识，分析了固体火箭发动机纤维缠绕壳体在燃气内压随机变化作用下的应力响应，绘出应力分布曲线，为固体火箭发动机结构可靠性评估奠定基础。     

有效载荷／运载火箭耦合分析的频域方法

盘算尖响函数综合技术导出了用耦合频响函数和无有效载荷的运载火箭界面加速度响应表示的有效载荷／运载火箭耦合动力分析的频域方法，给出了以自由界面的运载火箭模态分数放自由界面或固定界面有效载荷模态参数构成的耦合频响函数表达式。     

海洋平台在组合载荷作用下的随机域可靠性分析

本文对海洋平台在风、浪及海流等多种载荷组合作用下的可靠性进行了分析计算，采用优选随机载单元法进行结构数的随机域离散。文中的海洋平台算例结构表明了优选随机域单元法的高效性，以及在海洋工程的结构系统可靠性计算中的考虑载荷组合作用的必要性。     

考虑高载和阻尼介质时刚塑性圆板的塑性动力分析

本文研究了阻尼介质对刚塑性圆板在高载(冲击荷载)作用下塑性动力响应的影响,得到了解析解并对此解进行了讨论。当阻尼介质参数趋于零时,本文结果与无阻尼解一致。文中还画出了荷载与阻尼介质对圆板运动时间和板中心点残余挠度的影响曲线。     

基于多体分析的对接机构结构锁动力学仿真研究

分析了周边式空间对接机构结构锁的执行机构的特点，以及运用现有动力学分析软件解决此问题的困难；继而采用多体动力学建模方法，建立了结构锁执行机构的动力学模型，并针对本模型的特殊性采用了变步长的广义坐标分块求解算法；最后通过求解模型得到了机构的动力学特性曲线，证明了滚珠丝杆和弹簧复合机构作为结构锁执行部件是可行的．     

基于总线式集成框架的本体构建及映射研究

通过本体的构建及相应的本体映射策略,可以很好地解决信息集成过程中出现的语义异构问题。是实现异构数据源语义解析的基础。在已有研究成果总线式信息集成框架的基础上,针对目前本体构建过程存在的不足,提出了基于共享词汇表的全局本体构建技术和基于UML的局部本体构建技术,使所构建的本体元素间关系更加准确完备,具有良好的一致性。提出了基于综合相似度的本体映射策略,大大提高了本体映射的精度。     

A cost driven predictive maintenance policy for structural airframe maintenance

Airframe maintenance is traditionally performed at scheduled maintenance stops.The decision to repair a fuselage panel is based on a fixed crack size threshold,which allows to ensure the aircraft safety until the next scheduled maintenance stop.With progress in sensor technology and data processing techniques,structural health monitoring (SHM) systems are increasingly being considered in the aviation industry.SHM systems track the aircraft health state continuously,lead ing to the possibility of planning maintenance based on an actual state of aircraft rather than on a fixed schedule.This paper builds upon a model-based prognostics framework that the authors developed in their previous work,which couples the Extended Kalman filter (EKF) with a first order perturbation (FOP) method.By using the information given by this prognostics method,a novel cost driven predictive maintenance (CDPM) policy is proposed,which ensures the aircraft safety while minimizing the maintenance cost.The proposed policy is formally derived based on the trade-off between probabilities of occurrence of scheduled and unscheduled maintenance.A numerical case study simulating the maintenance process of an entire fleet of aircrafts is imple mented.Under the condition of assuring the same safety level,the CDPM is compared in terms of cost with two other maintenance policies:scheduled maintenance and threshold based SHM maintenance.The comparison results show CDPM could lead to significant cost savings.     

An equilibrium multi-objective optimum design for non-circular clearance hole of disk with discrete variables

An Equilibrium Multi-objective Optimization Model(EMOM) with self-regulated weighting factors has been proposed for the optimum design of non-circular clearance hole on the front flange of turbine disk. In the ‘‘equilibrium design", both the stress decrease around the hole and the least hole's profile variation are considered, which balances two ambivalent design goals. Specific discrete variables are applied to realize the standardization design in the optimization process, in which a Surrogate Genetic Coding Algorithm(SGCA) is introduced, and a special check module is used to get rid of repeated fitness evaluation of the samples. The method offers an equilibrium design for the non-circular clearance hole of the turbine disk with great accuracy and efficiency.     

A new structural reliability index based on uncertainty theory

The classical probabilistic reliability theory and fuzzy reliability theory cannot directly measure the uncertainty of structural reliability with uncertain variables,i.e.,subjective random and fuzzy variables.In order to simultaneously satisfy the duality of randomness and subadditivity of fuzziness in the reliability problem,a new quantification method for the reliability of structures is presented based on uncertainty theory,and an uncertainty-theory-based perspective of classical Cornell reliability index is explored.In this paper,by introducing the uncertainty theory,we adopt the uncertain measure to quantify the reliability of structures for the subjective probability or fuzzy variables,instead of probabilistic and possibilistic measures.We utilize uncertain variables to uniformly represent the subjective random and fuzzy parameters,based on which we derive solutions to analyze the uncertainty reliability of structures with uncertainty distributions.Moreover,we propose the Cornell uncertainty reliability index based on the uncertain expected value and variance.Experimental results on three numerical applications demonstrate the validity of the proposed method.