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181.
Development of a PC-based Open Architecture Software-CNC System 总被引:1,自引:0,他引:1
MA Xiong-bo HAN Zhen-yu WANG Yong-zhang FU Hong-ya 《中国航空学报》2007,20(3):272-281
As a key technology in the field of advanced manufacturing, an open architecture controller is studied. In order to develop an open architecture software-CNC system on personal computer (PC) according to open modular architecture controllers (OMAC). First, the software and hardware platform is chosen and software realization methodology for the CNC system is determined. Second, static mod- eling methods of an open architecture controller inclusive of object-oriented (OO) programming technology, dynamic link library (DLL) technology and system modules partition are investigated. Third, the dynamical behavioral modeling and the data flow representation of open architecture controller are discussed, which are both described in hierarchy finite state machine (FSM) model. Fourth, a reusable software module model is established to develop software function module library. Finally, a 3-axis milling machine tool test-bed, named for HIT-CNC, is successfully designed by means of the constructed software function module library and the system configuring method. The experimental results show that, besides increasing the degree of reusability and openness, application of above-mentioned method- ology leads to significant decrease of development time as well as maintenance cost. 相似文献
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183.
The LM-5B carrier rocket’s first stage is equipped with eight 120 t. thrust high-pressure staged combustion LOX/kerosene engines(YF-100). The YF-100 engine features a throttle valve in the main fuel path, which allows the adjustment of the throttle area, thereby controlling the engine’s mixture ratio. Engine parameters for the throttle valve were determined based on design conditions(mixture ratio of 2.6), and the engine was then tested for ignition.After testing, if the mixture ratio was found ... 相似文献
184.
The arc milling method has the advantages of high machining efficiency and low cost and is independent of the strength and hardness of machined materials. However, frequent electrode back-offs and the risk of workpiece burning may occur if erosion products are not removed promptly. In this study, it was found that the flushing method of the working medium had a significant impact on the machining performance of arc milling. Based on this, a novel highefficiency compound machining method of elect... 相似文献
185.
Liquid film cooling as an advanced cooling technology is widely used in space vehicles.Stable operation of liquid film along the rocket combustion inner wall is crucial for thermal protection of rocket engines.The stability of liquid film is mainly determined by the characteristics of interfacial wave,which is rarely investigated right now.How to improve the stability of thin film has become a hot spot.In view of this,an advanced model based on the conventional Volume of Fluid(VOF) model is adop... 相似文献
186.
在篦齿封严装置减振的开口阻尼环设计方法的基础上,对比研究了阻尼套筒的设计方法.采用动柔度法求解了安装有阻尼套筒的篦齿封严装置的动力响应.分析了阻尼套筒结构尺寸(厚度、接触面积)和安装过盈量等参数对篦齿封严装置动力响应的影响规律;在篦齿封严装置和阻尼套筒的组合结构中,存在最佳的阻尼套筒结构参数,此时阻尼套筒减振效果最佳;对组合结构不同的周波型振动,阻尼套筒的减振效果不同. 相似文献
187.
关于航空发动机结构声疲劳寿命估算方法的探讨 总被引:8,自引:5,他引:8
噪声载荷是一种高频、宽带随机载荷,在低循环疲劳寿命预测中被广泛采用的时域计数法很难直接利用。根据现有的累积疲劳损伤理论,噪声载荷下结构疲劳寿命分析的关键在于如何在频域中获得雨流循环的概率密度函数。本文对从疲劳应力功率谱密度出发获得寿命估算所需要的应力峰值或应力雨流循环幅值的概率密度函数的方法进行了分析与比较,并对发动机结构声疲劳分析中值得深入研究及发展的方法给出了建议。 相似文献
188.
本文研究了具有干摩擦阻尼的带冠叶盘系统振动响应的求解问题。解决了时频法中由于叠混和泄漏而使迭代发散的问题。最后用时频法获得了令人满意的响应计算结果。 相似文献
189.
利用行波振动分析方法,结合周期对称理论的应用,对某机风扇机匣第1级静叶掉角的故障原因进行分析,得出了与实际相符的结论。本文的分析是利用大型结构分析软件NASTRAN完成的。 相似文献
190.