轴压薄壁加筋圆柱壳结构优化设计研究

分别建立了轴向载荷作用下正置正交薄壁加筋圆柱壳结构优化设计的数学模型和有限元分析模型,应用Ansys软件进行优化计算,讨论了外载荷、材料屈服极限对优化设计的影响,以及结构参数对薄壁加筋圆柱壳结构的临界载荷和屈曲模式的影响。基于有限元分析的研究结论,发展了一种薄壁加筋圆柱壳结构优化设计方法,给出设计算例的优化结果,并将两...     

战斗部虚拟试验与验证技术研究

提出了虚拟试验及验证的概念．在战斗部研制过程中引入了虚拟试验与验证技术。通过建立战斗部虚拟试验与验证平台，采用虚拟试验验证技术评估和提高虚拟试验结果准确度和可靠性。在战斗部研制过程中利用虚拟试验部分代替物理试验．可降低研制成本．缩短研制周期和提高研制质量。     

垂直管内通气空泡掺气过程仿真分析简

A semi-empirical gas entrainment model was proposed for the ventilated cavity in vertical pipe, based on which, a complete numerical scheme was established by coupling with the Eulerian-Eulerian two-fluid model to predict the multiscale flow field created by ventilated cavity. Model predictions were validated against experimental measurements on void fraction and bubble size distributions. Simulations were carried out to explore the effect of ventilation rate and inlet turbulence intensity on the macroscale cavity shape and the bubbly flow downstream of the ventilated cavity. As the ventilation rate increasing, a reverse trend was observed for the void fraction and bub- ble size distributions. It is concluded that the average void fraction in the pipe flow region is determined by the volumetric ratio between liquid and gas. However, the bubble size evolution is dominated by the breakage effect induced by turbulence in the vortex region. Furthermore, simulations were conducted to analyze geometric scale effect based upon Froude similitude. The results imply that the velocity distributions were properly scaled. Slight scale effect was seen for the void fraction caused by faster dispersion of bubbles in the larger size model. The com- paratively greater bubble size was predicted in the smaller model, implying significant scale effects in terms of tur- bulence and surface tension effect. It reveals that empirical correlations valid in wide range are required for the ex- trapolation from small-size laboratory models.     

基于信息增益的SLAM图精简

针对基于图论的同时定位与制图中,非线性约束方程组维数随机器人运行距离和时间的增加而不断增大的问题,提出一种基于信息增益的图精简算法.该算法通过评估精简前后特征点信息矩阵相对变化,删除观测信息量小于给定阈值的机器人位姿及相应的观测,达到显著简化优化问题的目的.根据测量球形协方差矩阵假设,给出了信息增益的精确和近似计算方法.通过恢复性图剪枝方法,确保图精简过程中的连通性.蒙特卡洛仿真和开源实验数据计算结果表明,在不引入明显的优化误差前提下,该方法可实现位姿和特征点90%的精简,显著提高图优化效率.     

聚能破甲战斗部参数建模技术研究

分析了影响聚能破甲战斗部性能的结构参数,采用基于特征的建模工具Pro/E及其二次开发工具,建立了包括罩锥角、炸高以及各种装配偏差的聚能破甲战斗部参数模型.     

基于预测模型的虚拟试验不确定性分析方法

 工程系统中不可避免地存在各种参数不确定性,利用数值计算模型对系统进行虚拟试验时应进行不确定性分析.大型耗时计算模型的不确定性分析将面临严重的的计算复杂性问题,为此,针对工程应用中耗时计算模型,提出一种基于贝叶斯预测模型的不确定性分析仿真方法,采用概率分布为参数不确定性建模,研究系统响应预测不确定性的概率特征.泰勒杆撞击实例验证了该方法的高效性.     

悬浮抱杆组塔工艺承力检测系统设计与应用

电力铁塔组立是危险系数极高的工作。为了保障施工安全，施工前有安全作业理论验算和严格的施工流程步骤管理，施工中有各种规章制度约束并采用视频监控等方式进行监督。但上述方式缺乏直接的力检测手段，为解决此难题，提出一种适用于内悬浮外(内)拉线组塔工艺承力系统的力检测方案，检测其吊装过程中抱杆系统的受力情况。以实际应用为目标，针对抱杆系统开发出卸扣力传感器、钢丝绳张力传感器和抱杆姿态仪等设备，详细说明了各传感器的安装位置，结合ZigBee无线通信技术，配合上位机软件，实现对组塔吊装过程的实时监控和预测预警。通过现场试用，表明该检测系统测量精确、安装方便，能满足现场检测要求。