试验设计

With a model ZJ15 rig substructure as antetype, and according to similarity theory, the design of a substructure model is accomplished on the basis of detailed analysis of vibration data of ZJ15 rig substructures and fully consideration of test purposes.

在详细分析现役 ZJ15型钻机底座振动测试数据及充分考虑试验目的的基础上，以一种 ZJ15型钻机底座为原型，按照相似理论求出各个相似常数并设计出钻机底座模型，以便进行多种模态试验和振动模拟试验。

This paper introduces the experimental study on the model test of anchoring joint of stay cable used in Nanjing railway station, including the finite element analysis, the design of the test installation, the test results analysis, etc.

较详细地介绍了南京站主站房斜拉索锚固节点的试验过程，包括有限元计算、试验装置设计、试验结果分析等。

The author determines the fatigue property in super long life region of the cruciform joint of 16MnR base material of one ...

作者利用瑞士RUMAL电磁高频疲劳试验机测定16MnR板材十字单面焊接接头在超长寿命区间的疲劳性能，并采用标准法和Dixon-Mood法对测得的试验数据进行处理，整理出十字单面焊接接头在超长寿命区间的疲劳极限，这些结果可以为焊接结构的可靠性设计及服务寿命估计提供试验数据基础。

The effect of tribology factors on bearing vibration is studied experimentally. AR model and WPT are used to processing the normal arid abnormal signals. The results are as follows:1. The vibration of ball bearings is caused by the tribology action of contact pairs of ball and ring races and has the essential of tribo-dynamics. Any factors affecting the tribology characteristics of contact pairs will affect vibration and noise of bearings consequently.2. Vibration characteristics of bearing keep almostly unchanged with the increasing of axial load expecting the increasing of nature frequencies. When radial load increasing with axial load unchanged, nature frequencies keep unchanged but some new vibration peaks appears in the spectrum.3. Vibration amplitudes are damped and nature frequency are enhanced with sufficient lubrication. Vibration and noise of bearings increase obviously and roar can happen and the contact surfaces scratch slightly under insufficient and unclean lubrication state. Bearing will be disabled in a few minutes without any lubrication.4. Bearing vibration is unstable under low speed. With the speed increasing, the vibration become stable and natural frequencies increase slightly but the amplitudes increase apparently.5. Bearing vibration can be excited only by some harmonics ofwaviness without lubrication and by all harmonics with lubrication based on the theoretical analysis.6. The nature frequencies of ball bearings decrease with the increasing sizes. When international clearance increasing, nature frequencies decrease in radial and increase in axial and angular and the amplitudes increase in radial and decrease in axial and angular. When the number of balls increasing, nature frequencies increase and amplitudes decrease. When the pitch diameter increasing, axial nature frequency increase and others nearly keep no change. When outer race groove curvature radius increasing, nature frequencies increase in radial and decrease in axial and angular and amplitudes keep no change in radial and increase in axial and angular. When inner race groove curvature radius increasing, nature frequencies decrease and amplitudes increase.7. The distortion in amplitude and frequency components of bearing vibration signals picked up by the present probe measurement method is founded and right conclusions cannot be achieved by the signals. When accelerometer is rigidly screwed with steel stud onto a flat outer surface of a ball bearing, vibration signal can be got without distortion and the reliability of research on bearing vibration is assured.8. AR model is suitable for large samples of bearing vibration signals, square root of length of samples can be used as the upper limitation of order determination and the FPE order selection criterion is effective. Many advantages of AR spectrum are founded over the classical based on FFT.9. Time-Frequency analysis is necessary for abnormal noise of ball bearings. WPT overcomes the principle shortcomings of STFT and proved to be a best tool to process the abnormal signals.

理论分析和试验研究表明： 1球轴承振动是钢球—滚道接触副中的各种摩擦学作用引起的，具有摩擦动力学的本质，任何对接触副的摩擦学特性有影响的因素都将对球轴承的振动和噪声特性产生影响； 2中心轴向载荷作用下，载荷增大使球轴承的固有振动频率升高，载荷越大同样的载荷增幅引起的频率升幅减小，足够大的中心轴向载荷作用下载荷的变化对球轴承振动的频率特性不会产生明显的影响； 3轴向和径向联合载荷作用下，径向载荷不大时球轴承振动的固有频率基本不变，但是可能引起变刚度激励的非线性振动，出现新的频峰，过大的径向载荷将使部分钢球脱离接触，使球轴承的振动和噪声呈现不稳定状态； 4润滑对球轴承的振动和噪声特性有重要的影响，良好的润滑对振动有明显的抑制作用，润滑不充分时，振动和噪声的水平会有明显增高，一定条件下还会激发接触副中的谐振，发出啸声，造成接触表面的伤害，无润滑干接触时，短时的运转就会损伤接触副表面，使振动和噪声迅速增大，并随时可能引发严重的磨损和卡滞失效；接触副润滑良好时，油膜的"刚化效应"使球轴承振动的固有频率有所提高，润滑剂中含有弥散性污浊时，振动的幅度总体升高，但弥散性污浊不会改变球轴承振动的频率特性；浙江大学博士学位论文：球轴承振动的研究 5低速时，球轴承振动的基本特征呈现不稳定状态，随着转速的提高，球轴承振动的频率特性趋于稳定，固有频率频峰升高； 6理论分析表明，干接触时钢球和滚道表面波纹度的某些谐波分量能激励球轴承的振动，振动的幅值与谐波幅值成正比，实际球轴承中钢球的分布不可能完全均匀，波纹度的激励作用会随时发生；润滑接触的分析表明，波纹度的任意谐波分量均能激励球轴承的振动； 7球轴承的几何和结构参数分析表明，球轴承尺寸越大，径向、轴向和角振动的固有频率越低；钢球中心圆直径增大，球轴承的径向和轴向振动的固有频率基本不变，角振动的固有频率有所上升，振动的幅频特性基本不变；径向游隙加大使球轴承的径向振动固有频率降低，轴向和角振动的固有频率有所升高，径向振动幅频特性的幅值升高，而轴向和角向降低；钢球的数量增多使球轴承振动的固有频率上升，幅频特性的幅值下降，径向振动的幅值下降最为明显；外圈沟曲率半径系数增大使球轴承径向振动的固有频率升高，轴向和角振动的固有频率降低，径向幅频特性基本不变，轴向和角向幅频特性幅值升高；内圈沟曲率半径系数增大使径向、轴向和角振动固有频率均下降，振动幅频特性的幅值均有升高； 8试验对比表明，传感器采用探针式安装时，由于探针接触副接触特性的影响，钡(量得到的球轴承振动信号有失真，采用专门设计和制作的试验球轴承，以固定式安装加速度计，首次测量得到了球轴承振动的真实信号，通过对振动信号的分析，验证了球轴承振动的理论模型； 9)基于时间序列分析的AR模型适用于大样本球轴承振动信号的分析，以样本长度的均方根值作定阶上界，FPE做判阶准则，给出的AR谱光滑，频率分辨率高，是球轴承振动分析的简便而可靠的手段； 10以时频域分析的小波包变换分析球轴承异音信号能够比较好地定位和聚焦异音发生的时间，时间间隔，频率范围，同样是球轴承振动分析的可靠的手段，可用作球轴承故障诊断技术。

To accelerate the widespread of Synchronous Chip Seal and improve the operation quality of Synchronous Chipsealer, key techniques which influence the operation quality is studied detailedly, including the control of distributing quality, the dynamics characteristics of hydraulic system and the spray characteristics of asphalt nozzle of Synchronous Chipsealer.1 The factors which influence Synchronous Chip Seal quality are studied. Fiducial probability of simultaneous distribution density is advised to be used in evaluating the distribution bias and standard deviation of asphalt and aggregates simultaneously, which is more advanced than the single index evaluation method used before.2 The volume efficiency formula of asphalt pump is revised after analyzing the data of volume efficiency with mathematical statistics, which is helpful to match the asphalt spray system and control the flow out of asphalt pump accurately. With equation deduction and experiment, dynamic of hydraulic system used in Synchronous Chipsealer is studied, which lay the theory foundation on improving the stability and efficiency from design and controlling.4 Simulation on hydraulic system used in Synchronous Chipsealer is done with AMESim; the results indicate that multi-circle parallel connected hydraulic system with constant pressure power is better than that with load-sensing pressure power at present, because the latter will oscillate when the multi circles work at the same time. This conclusion has been proved during the debug of Synchronous Chipsealer.5 Asphalt nozzle characteristics, such as flat jet shape, flow distribution, are studied with experiment, the results indicate that cross quality of asphalt distributing is not increased linearly follow the increase of fan overlap level, the best point usually exists between two whole overlap level, asphalt distributing quality is better than±4% at the 2.5 overlap level, meets the superior specified in standard; The distribution quality of Synchronous Chipsealer can be increased by spray asphalt of different flow rang with nozzle of different diameter

为了加快同步碎石封层技术的推广，提高同步碎石封层设备的作业质量，本文对同步碎石封层设备作业质量的影响因素与控制方法、液压系统的动力学特性和沥青喷嘴的喷洒特性等关键技术进行了深入细致的研究：1研究了影响同步碎石封层作业质量的因素，提出了采用联合密度分布置信概率对同步碎石封层中沥青洒布量和碎石撒布量的系统偏差和标准差指标进行综合评价的方法，克服了传统评价方法只能对单一指标进行评价的缺陷；2采用数理统计的方法，研究了沥青泵的容积效率特性，修正了沥青泵容积效率公式，为沥青喷洒系统的匹配和沥青泵出口流量的精确控制提供了依据；采用数理方程推导与试验相结合的方法，研究了同步碎石封层设备液压系统的动力学特性，为从设计和控制的角度提高同步碎石封层设备液压系统的稳定性和效率奠定了理论基础；3运用AMESim软件对采用负载敏感控制和恒压控制的两种同步碎石封层设备液压系统进行仿真，结果表明：负载敏感控制的并联液压系统在多回路同时工作时，由于液压泵排量控制参考压力不稳定，容易引发液压系统振荡，恒压控制的并联液压系统是目前技术条件下比较理想的同步碎石封层设备工作装置驱动方案；该结论亦通过同步碎石封层设备装机试验得到了验证。4采用试验的方法对沥青喷嘴的喷洒特性进行了研究，结果表明：沥青洒布的横向精度并不是随着喷洒扇面重叠度的增加线性增加，其最高点通常出现在二个重叠度之间的"半重叠位置"，"2.5重叠"洒布时，沥青的横向洒布精度≤±4%，可以达到国家相关标准中的优级标准；同步碎石封层设备还可以根据不同洒布量情况下的流量需求，采用不同通径的喷嘴进行喷洒，提高沥青洒布精度。

The changes of superoxide dismutase, malonic dialdehyde and glutathione peroxidase were compared before and after the trial.

结果：受试者依从性好，除1人因试验期间发现肿瘤而退出试验，42名志愿者按设计要求完成试验。

Based on the especial character of eolian sand,we redesigh the way and equpment of experiment.

根据风积砂的特殊性质重新设计了试验设备和试验方案完成室内力学试验。

The modal tests of PCB and PCB assembly (free boundary condition and fixed boundary condition) were carried out. The equivalent elastic modulus and damping parameters of PCB can be gained, and the fixed boundary condition of finite element model was also determined. These will help to the following work.Second, drop impact tests of three different heights were carried out. Strains and acceleration responses of PCB were measured. Failed BGA packages of different test conditions were dyeing, and cross section analysis of failed solder joints was conducted.

针对JEDEC标准试件的局限性，提出了设计便于统计学研究焊点可靠性的试验试件的构想，利用有限元模态分析方法确定并验证了用圆形PCB组件替代JEDEC标准试件的可行性；通过一系列模态试验和有限元模态分析，确定了圆形PCB组件的相关试验参数，这不仅为跌落碰撞下PCB组件有限元模拟确定了较为合理准确的有限元模型，而且为正确地评价跌落碰撞下PCB组件的可靠性问题奠定了基础。2。

The modal tests of PCB and PCB assembly (free boundary condition and fixed boundary condition) were carried out. The equivalent elastic modulus and damping parameters of PCB can be gained, and the fixed boundary condition of finite element model was also determined. These will help to the following work. Second, drop impact tests of three different heights were carried out. Strains and acceleration responses of PCB were measured. Failed BGA packages of different test conditions were dyeing, and cross section analysis of failed solder joints was conducted. It was found in our drop tests that the root cause of lead-free solder joints under drop impact was the combined effect of mechanical shock and PCB bending vibration.

针对JEDEC标准试件的局限性，提出了设计便于统计学研究焊点可靠性的试验试件的构想，利用有限元模态分析方法确定并验证了用圆形PCB组件替代JEDEC标准试件的可行性；通过一系列模态试验和有限元模态分析，确定了圆形PCB组件的相关试验参数，这不仅为跌落碰撞下PCB组件有限元模拟确定了较为合理准确的有限元模型，而且为正确地评价跌落碰撞下PCB组件的可靠性问题奠定了基础。

The hailstone impacting test system is constructed basing on the theory of air gun which energy is offered by compressed air.

冰雹撞击试验系统是以压缩空气为动力的空气炮原理构建的，在设计时系统参数选择决定了试验的成功与否，同样在试验阶段时也需要根据技术要求选择各参数。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。