横梁

This paper researches the application of commonly used optimization design methods in new moving crossbeam of hydraulic press .

本文研究了常用优化设计方法在新的水压机活动横梁中的应用，对活动横梁的结构参数进行了优化，保证设计方案达到最佳；并建立了活动横梁的有限元力学模型，对该结构进行了三维有限元强度分析。

Based on the construction features of the Upper Beam of Large Open-die Forging Hydraulic Press,a finite element model has been established by using large-scale finite element analysis software I-DEAS,and the structural stress and displacement of the upper beam under all sorts of loads have been analyzed.

根据某大型自由锻造油压机上横梁的结构特点，利用大型通用有限元分析软件I-DEAS建立有限元模型，并对上横梁进行了静力学的有限元分析计算，研究了在满负荷工作状态下上横梁的结构应力以及位移情况。

Taken example for solving real engineering problem, the methods and steps for the analysis of the steering-wheel vibration is discussed.

为了解决某型轿车的转向盘振动问题，本文通过对影响转向盘振动的诸多因素逐一进行分析，结合先进的试验手段和CAE分析技术，找出了引发该轿车转向盘振动的主要原因是车轮动平衡质量不合格及固定转向柱管的仪表板横梁刚度不足，通过提高车轮动平衡质量，改进仪表板横梁设计，提高仪表板横梁的刚度和固有振动频率，结合道路试验进行主观评价，改进后的转向盘振动达到了平顺性要求。

In the part of the vibration experiments and analysis, firstly, used the simple-beam theory to estimate the natural frequency of the beam of the 20-headed computerized embroidery machine.secondly, measured the beam of its low rank natural frequency, the beams horizontal vibrating acceleration amplitude, speed amplitude and the displacement amplitude in different rev and different turn parts. Found that it is sympathetic vibration, which bring on the thread-broken rate rise rapidly. On this base, established the finite element analysis modle of the vibrating beam, and took on hamonic analysis and modal analysis with the mold. The rusult of test and analysis offer the basis for farther improvement of the computerized embroidery machine.

振动分析部分，首先由简单梁理论出发，对横梁的固有频率进行估算；接着通过测振仪器对20头电脑刺绣机横梁进行了试验模态分析和不同工况振动测试；获得了横梁前四阶固有频率和模态振型，以及在不同工作转速、不同回转部件下横梁振动的加速度幅值、速度幅值和位移幅值；找到了横梁振动加剧的原因——共振；在此基础上建立了符合实际情况的横梁有限元模型，对模型进行了模态和谐响应计算，证实了模型的可靠性，为下一步的改进设计提供了依据。

The results show that, with the same steel consumption, the longitudinal and transverse girder deck scheme is a little better in stiffness, dynamic characteristics and stability than those of the other scheme's. For the dense transverse girder deck scheme, because of no longitudinal beams, the axial forces of the tie beam and the deck slab are higher than those of the other scheme's. The improving rate of the axial force for the deck slab is about 50%. The inside and outside bending moments of the cross beams reduce to below half of the other scheme's. The longitudinal stress of the deck slab is higher on the whole and the traverse stress is less than that of the other scheme's. The maximum traverse stress of the deck slab is below 40% of the other scheme's.

研究结果表明：在材料用量相同时，纵横梁方案桥梁刚度较密布横梁方案的桥梁刚度稍大，桥梁动力特性比后者的优，其稳定性也比后者的强；对于密布横梁方案，由于不设纵梁，系梁和混凝土板承受的纵向力都较纵横梁方案的大，混凝土板增幅达50%左右，横梁面内和面外弯矩则明显减小，都低于纵横梁方案的一半，混凝土板顺桥向应力整体比纵横梁方案的高，而横桥向应力则较低，最大值低于纵横梁方案的40%。

For two parallel, interconnected beams, the beam with the greater load shall be considered as unbraced and the other beam as braced at the points of interconnection.

对于同方向互联的两个横梁，负荷较大的那个横梁被视为不加支撑的，另外一个横梁在互联点处为不加支撑的。

Beams supporting metal deck or slabs formed with metal decking may be considered supported at points of attachment between the beam and the deck.

如果横梁用于支撑金属板平顶屋或者用于支撑由金属面板组成的厚平板，则可认为此横梁的支撑点在横梁与平台之间的附属物上。

The results show that space finite analysis results are close to test ones, bottom chords suffer axial force and large in-plane bending, and the max stress is nearby each middle internode. The max stress of node crossbeams occurs in No.2 bottom flange, and that of internode crossbeams happens in ones lying in the middle of every internode. The concrete slab is in tension at the longitudinal direction, and also suffers bent at vertical loads. The degree of completely-composite model taking part in the combined actions is about 55%, while that of semi-composite model is 42%-43%. The combination of concrete slab and bottom chord increases the degree of floor system taking part in the combined actions, lightens the burden of bottom chord, and reduces out-of-plane bending of node crossbeams especially the ones near bridgehead. Stress and displacement of main truss can be evaluated by a equivalent plane rigid frame in preliminary design, and effective stiffness of bottom chords are composed of original ones and concrete slab, and the concentrated load from deck can be translated into uniform load.

研究结果表明：空间有限元分析结果与试验结果较吻合；下弦杆受到轴向拉力和较大的面内弯矩作用，各节间最大应力出现在节间中点附近；节点横梁最大应力发生在横梁2的下翼缘，节间横梁最大应力发生在位于端节间中部的小横梁上；混凝土板顺桥向整体受拉，并在竖向集中荷载作用下产生弯曲变形；全结合模型大部分节间内的桥面板参与主桁共同作用的程度为55%左右，半结合模型桥面板的参与程度为42%~43%；桥面板与下弦杆结合能够增加桥面板的参与程度，减轻下弦杆荷载，减少节点横梁尤其是靠近桥头横梁的面外弯曲；对桥梁进行初步设计时，主桁杆件的位移与内力可按照1个等效的平面刚架计算，下弦杆的等效刚度由原下弦杆截面和混凝土桥面板截面组合而成，桥面荷载可转化为均布荷载施加。

The static and dynamic characteristics of the beam of a gantry-type machining center are analyzed by means of ADAMS and ANSYS. Considering effect of gravity and cutting forces, the static deformation of the beam is obtained after calculating the interacting forces between the guide and the slide block by ADAMS. Moreover, the contact parameters of the guide surface are acquired by dynamic tests and parameter identification, then they are applied to the simulation model of the beam-slide box system, whose natural frequencies and modal shapes are achieved by modal analysis. Furthermore, the effect of changes of the contact parameters on the dynamic behavior of the beam-slide box system is also investigated.

对一种国产龙门式加工中心的横梁关键部件，采用机械系统多刚体动力学仿真软件ADAMS和有限元分析软件ANSYS进行了静动态特性分析；在考虑重力和切削力作用下，由ADAMS计算出导轨与滑块间的作用力，从而计算出横梁部件的静态变形；通过动态测试和参数辨识方法获得导轨结合面特性参数并将其应用到横梁滑箱系统整体有限元模型中，经过模态分析得到系统固有频率和各阶振型图，并进一步分析了结合面参数变化对横梁滑箱系统整体动态特性的影响。

The vibration test is marked in different velocities to probe the effective way of the beam damping by changing the fixed type of the beam on two ends,setting up the curve beam with right angle to sustain the beam,and installing the rubber damper,so as to reduce the amplitude of the beam .

通过改变横梁两端固定方式，增设直角弯梁后撑横梁，加装横梁橡胶减振器等方法，在不同速度工况下进行振动测试，以减小横梁振动的幅值。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。