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61.
对在不同射角下符合时,由射表误差源造成的射程误差和偏流误差进行了计算与分析,论述了符合射角选择的合理区域。通过综合考察各种因素对于射表误差的影响,提出了以45°射角作为最佳符合射角的方案。同时模拟对比了分别采用新方法编表和传统方法编表时的射表精度.结果表明,尽管新方法的编表所需符合射角由原来的5个以上减少为1个,但编表精度却反而提高。  相似文献   
62.
提出了GPS/平台式静电陀螺找北仪组合系统方案。它具有找北精度高、机动性强、对准时间短、能实时辨识陀螺漂移模型等特点,是实现自主找北的一种新方案,具有实用价值。  相似文献   
63.
较为详细地推导了鱼雷转角射击公式,根据分鱼雷转向的不同总结出两类求解公式(各种态好都能用两类公式之一来解算).最后还讨论了所导出的非线性方程的数值解算方法,该算法具有工程应用价值。  相似文献   
64.
本文对于在炸药驱动下空气中的二维抛板理论模型,提出了一种具有较普遍意义的简化处理方案。  相似文献   
65.
《防务技术》2020,16(2):408-416
Ceramic balls represent a new type of damaging element, and studies on their damaging power of composite armor are required for a comprehensive evaluation of the effectiveness of various types of weapons. The goal of this study was to determine the impact of ϕ7 mm toughened Al2O3 ceramic balls on a composite ceramic/metal armor. The influences of the ceramic panel and the thickness of the metal backing material on the destroying power of the ceramic balls were first determined. Based on the agreement between numerical simulation, experimental results, and calculation models of the target plate resistance, the response mechanism of the ceramic balls was further analyzed. The results indicate that for a back plate of Q235 steel, with an increasing thickness of the ceramic panel, the piercing speed limit of the ceramic balls gradually increases and the diameter of the out-going hole on the metal back decreases. Different conditions were tested to assess the effects on the piercing speed, the diameter of the out-going hole, the micro-element stress, and the integrity of the recovered ceramic bowl.  相似文献   
66.
基于火箭(导弹)级间螺栓法兰连接结构,简化设计并制作了一组原理性实验件,利用ABAQUS软件建立有限元模型,设计并进行了多次落锤冲击失效实验,其中包括轴向和横向两种工况,考虑了螺栓均布与非均布、螺栓直径和螺栓-栓孔间隙等不同结构特点。实验过程中采集了螺栓力时程响应数据、柱段关键点应变时程响应数据、锤头冲击力和冲击速度及连接界面开缝位移等多组数据。根据实验效果和实测数据,分析了连接结构冲击失效机理,并对比验证发现有限元模型数值模拟效果和精度与实验结果吻合较好。研究结论可为箭(弹)级间连接结构抗冲击设计提供参考。  相似文献   
67.
We consider the problem of finding the system with the best primary performance measure among a finite number of simulated systems in the presence of a stochastic constraint on a single real‐valued secondary performance measure. Solving this problem requires the identification and removal from consideration of infeasible systems (Phase I) and of systems whose primary performance measure is dominated by that of other feasible systems (Phase II). We use indifference zones in both phases and consider two approaches, namely, carrying out Phases I and II sequentially and carrying out Phases I and II simultaneously, and we provide specific example procedures of each type. We present theoretical results guaranteeing that our approaches (general and specific, sequential and simultaneous) yield the best system with at least a prespecified probability, and we provide a portion of an extensive numerical study aimed at evaluating and comparing the performance of our approaches. The experimental results show that both new procedures are useful for constrained ranking and selection, with neither procedure showing uniform superiority over the other.© 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010  相似文献   
68.
针对反弹道导弹的导弹武器的主动飞行段,提出了高精度自适应现状制导律。通过实时修正飞行程序,以消除导弹飞行过程中遇到的各种干扰的影响,保证命中精度,并对发动机推力偏差、风干扰影响下的导弹运动进行了数学仿真,仿真结果证实了自适应现状制导律是合理、可行的。  相似文献   
69.
We consider the scheduling of large‐scale projects to maximize the project net present value given temporal and resource constraints. The net present value objective emphasizes the financial aspects of project management. Temporal constraints between the start times of activities make it possible to handle practical problem assumptions. Scarce resources are an expression of rising cost. Since optimization techniques are not expedient to solve such problems and most heuristic methods known from literature cannot deal with general temporal constraints, we propose a new bidirectional priority‐rule based method. Scheduling activities with positive cash flows as early and activities with negative cash flows as late as possible results in a method which is completed by unscheduling techniques to cope with scarce resources. In a computational experiment, we compare the well‐known serial generation scheme where all activities are scheduled as early as possible with the proposed bidirectional approach. On the basis of a comprehensive data set known from literature containing instances with up to 1002 activities, the efficiency of the new approach is demonstrated. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2003  相似文献   
70.
针对电磁探测卫星的特点,考虑其主要约束条件,建立了多星联合规划数学模型,提出了基于遗传算法的电磁探测卫星多星规划算法.为处理遗传算法迭代过程中产生的不可行解,引入了基于罚函数法的约束处理方法.针对罚函数法中惩罚系数难以确定的特点,设计了惩罚系数自适应调整的动态罚函数机制.根据模拟的数据进行实验及分析,表明该方法能有效解决电磁探测卫星多星规划问题.  相似文献   
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