试验

To break through the limit of continuous medium theory, a uniaxial compression test of HMA was simulated with discrete element method, and then the simulation was compared with the lab test.

为突破常规数值方法基于连续性的理想假设，进行了某级配的沥青混合料单轴压缩试验的离散元模拟，并将模拟试验与室内试验进行了比较。

Firstly, this paper investigated roundly the basic theory of the ambient vibration method, analyzed systematically the main methods of ambient vibration identification, and discussed their advantages and disadvantages. Then we established the finite element model of structural dynamics and test model and analyzed their mutual relation, improved MUSIC method and correlation function method in the harmonic identification, and gave the subspace method and correlation function method based on continuous model, which is multi-harmonic retrieve technique. And then, this paper also puts forward least-squares method to estimate directly structural physical and modal parameters; this approach replaced the derivative operator in the continuous time model with an equivalent approximation, and estimated the physical parameters of structures by the least-squares method. And then, we discussed the approximation methods of derivative and their convergence. Finally, this paper researched the modal parameters of a frame structure by the simulation and test. The results demonstrated that subspace method, correlation function method and the least-squares method are effective and stable respectively.

全面地研究环境振动识别方法的基本理论，系统地分析环境振动识别方法的主要方法，讨论它们的优点和不足；建立结(来源：6666AB44C论文网www.abclunwen.com)构动力学的有限元模型和试验模型，分析有限元模型与试验模型之间的相互关系；改进谐波识别中的MUSIC识别方法和相关函数识别方法，给出大型结构模态识别的连续型的子空间分解识别方法和相关函数识别方法，这个方法是多元谐波识别方法；提出直接识别结构的物理参数和模态参数的最小二乘方法，这个方法利用导数的近似值代替导数值，并运用最小二乘方法识别结构的物理参数，讨论导数近似值的选择方法，分析算法的收敛性；通过仿真计算和模型实验，研究高层框架结构的模态参数识别，验证子空间分解识别方法、相关函数识别方法和最小二乘识别方法的有效性，算法的稳定性；从理论和试验两个方面分析和研究噪声对识别精度的影响，影响识别精度的因素，以及部分模态成分的模态参数不能够被识别的原因。

Secondly, pollution emission nudging technique is introduced and used to correct urban average SO_2 and NO_X emission, error factor and convergence condition of emission nudging technique is studied and hourly SO_2 and CO emission of Peking is also experimented.

提出污染源"Nudging"修正模型，进行城市SO_2、NO_x排放强度的"Nudging"修正试验，讨论了"Nudging"试验的收敛条件和误差因子，并进行了北京SO_2和CO逐小时排放的"Nudging"修正试验。

Test results show that there are evident differences among creepage distance utilization coefficients of different types of insulators.

对华东电网常用的几种绝缘子的积污特性、爬电距离有效利用系数进行了分析和计算，同时，在污秽试验的基础上，对几种常见的绝缘子试品进行了长串耐压试验，试验结果表明，不同类型绝缘子的爬电距离有效利用系数存在较大差异。

The useful and important tests of sensibility are: testing the vibratory sensation with tuning fork, vibrometer testing for vibratory thresholds, von Frey testing (determined by Semmes－ Weinstein nylon monofilaments or Pressure－ Specifying Discriminator) for cutaneous pressure thresholds, measurement of static and moving two－ point discrimination with the Disk－ Criminator, Moberg's ninhydrin test, O'Rain skin wrinkling test, Picking－ up test, Tinel's sign and electrodiagnostic test.

此文对临床上重要且实用的皮肤感觉功能测定方法如音叉皮肤振动觉定性检查、振动觉阈的振动器定量测定、Semmes－Weinstein尼龙单丝或Pressure－SpecifyingDiscri minator行皮肤压觉阈的测定、用Disk－Criminator进行静止和运动的两点辨别觉测定、茚三酮试验、O'Rain指腹皮肤皱缩试验、捡物试验、Tinel's征电生理检查以及这些检查方法在神经断裂、神经卡压及神经损伤或修复后的恢复等情况中的应用和评价作一讨论。

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。

This paper discusses the problems met in static test as the setting of datum line beam and reference stake,compaction of main beam by jack,loading side test,and quick and slow loading method,in order to ensure scientificity and accuracy of static test data,and to improve the quality of pile foundation detection and the reliability of detection evaluation result.

对基准梁与基准桩的设置、主梁压实千斤顶、边堆载边试验、慢速与快速加荷法等静载试验中遇到的问题进行了探讨，以保证静载试验数据的科学性和准确性，从而提高了桩基检测工作的质量和检测评定结果的可靠性。

Studies the behaviour of ascorbic acid by carrying out deaeration tests, corrosion experiments and electrochemical tests.

通过除氧试验、腐蚀试验和电化学试验，研究了抗坏血酸在亚硫酸盐防腐蚀中的作用。

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 split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。