起重机

For portal cranes, jib crane system is the main one of the bearing components. mechanical properties of the normal functioning unit has a direct impact.

对于门座起重机而言，臂架系统是起重机主要的承载部件之一，其力学性能对整机的正常运转有着直接影响。

Main contents:(1) The paper introduces the structure form of portal crane jib system and analyses the working principle, process, parameters affection of four—bar portal crane.

具体说来，本论文的主要内容有：(1)综合介绍了门座起重机臂架系统的结构形式，重点分析了四连杆门座起重机的工作原理，工作过程以及各参数对整机工作性能的影响。

The paper builds finite element model of portal crane jib system using girder element, besides it presents its principles and process so that the foundation of this method is established. Besides, the paper builds the model in APDL which is easier to modify and administrate.

运用有限元分析软件ANSYS8.1对门座起重机的臂架系统建立有限元模型，给出了用梁单元建立有限元模型的原则和步骤，为今后用梁单元进一步开展门座起重机的有限元分析奠定基础，而且采用APDL语言可以实现参数化建模，对于模型易于修改、便于管理。

In concretionaly, these theses" primary coverage has:(1)Syntheses introduce portal crane jib systemic structural style structural style, selectively analysis four-bar linkage portal crane"s working theory, working process as well as each parameter to impact whole machines performance.

具体说来，本论文的主要内容有：(1)综合介绍了门座起重机臂架系统的结构形式，重点分析了四连杆门座起重机的工作原理，工作过程以及各参数对整机工作性能的影响。

This paper bases on the technique of virtual prototype and utilizes software platform of UG, ADAMS and ANSYS to establish three-dimensional digitized virtual prototype of double link jib system of portal crane and systematically do its analysis of dynamics emulation of multi-body system.

本文基于虚拟样机技术，利用UG、ADAMS、ANSYS软件平台，建立了门座起重机四连杆组合臂架系统的三维数字化虚拟样机，并对其进行了较为系统的多体系统动力学仿真分析，实现了计算机对组合臂架系统在各种工况下随载荷变化的运行状态及随时间变化过程的仿真，得到的相关仿真分析数据对于门座起重机组合臂架系统动态设计提供了有效的手段。

The jib system of portal crane is considered to be elastomer in this paper. Besides, taking finite element as basic theory and mechanical dynamics as analysis method,the paper simulates the virtual luffing process of jib system and seeking the relationship between plane movement and dynamic pressure condition of jib system using ANSYS8.1. By analyzing ,the paper gives some advice on structure optimizing.

针对以上问题，本文以MQ2535门座起重机臂架系统为研究对象，将门座起重机整个臂架系统视为弹性体，以机械动力学和有限元为理论基础和分析手段，运用有限元软件ANSYS8.1模拟臂架系统的实际变幅过程，探寻物品在变幅过程中水平移动与臂架系统结构动态受力之间的关系；通过分析其受力情况，对其结构的优化提出了一些建议。

Based on the modern crane design skill, this paper designs and analyses the hoisting mechanism of the high pedestal jib crane, involves armoured rope、drum、sliding wheel、electric motor、reducing device and arresting gear.

本文以先进的起重机设计技术为基础，对门座式起重机起升机构的钢丝绳、卷筒、滑轮、电动机、减速器、制动器等进行了设计分析。

Feeder loadingbridge is to improve from a crane, so the overall table withreference to the principle of a crane to carry out the design Thistime designs me mainly to aim at this machinery the king post andthe car actuates the system to carry on the design.

桥式装卸料机是由起重机改进而来的，因此总体上来是参照起重机的原理来进行设计。本次设计我主要针对该机械的主梁和小车驱动系统进行设计。

After the fatigue curve with 50% reliability and a few fatigue test results of a crane element have been known, the method, namely JFKC method, in this paper can be used to get the fatigue limiting stress distribution of this crane element quickly, based on the Miner Hypothesis and.

本文在已知某种起重机零件可靠度为50%的疲劳曲线并有了该种零件的少量试件的疫劳试验结果的条件下，以作者提出的修正的曼耐尔假设和抛物线假设为基础，提出了起重机零件疲劳极限应力分布的快速测定法——JFKC*法。

So we find a new way to meliorate structures dynamic characteristics. By this means, I analyze the dynamic characteristics and stiffness of similar crane.

并以ZPMC为Miami港制造的一台集装箱起重机为模型，进行理论分析及研究改善，对类似港口起重机的刚度进行分析。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。