附录一英文科技文献翻译
英文原文：
Experimental investigation of laser surface textured parallel thrust bearings
Performance enhancements by laser surface texturing (LST) of parallel-thrust bearings is experimentally investigated. Test
results are compared with a theoretical model and good correlation is found over the relevant operating conditions. A compari-
son of the performance of unidirectional and bi-directional partial-LST bearings with that of a baseline, untextured bearing is
presented showing the bene?ts of LST in terms of increased clearance and reduced friction.
KEY WORDS: ?uid ?lm bearings, slider bearings, surface texturing
1. Introduction
The classical theory of hydrodynamic lubrication yields linear (Couette) velocity distribution with zero pressure gradients between smooth parallel surfaces under steady-state sliding. This results in an unstable hydrodynamic ?lm that would collapse under any external force acting normal to the surfaces. However, experience shows that stable lubricating ?lms can develop between parallel sliding surfaces, generally because of some mechanism that relaxes one or more of the assumptions of the classical theory.
A stable ?uid ?lm with su?cient load-carrying capacity in parallel sliding surfaces can be obtained, for example, with macro or micro surface structure of di?erent types. These include waviness [1] and protruding microasperities [2–4]. A good literature review on the subject can be found in Ref. [5]. More recently, laser surface texturing (LST) [6–8], as well as inlet roughening by longitudinal or transverse grooves [9] were suggested to provide load capacity in parallel sliding. The inlet roughness concept of Tonder [9] is based on ??e?ective clearance‘‘ reduction in the sliding
direction and in this respect it is identical to the par- tial-LST concept described in ref.
[10] for generating hydrostatic e?ect in high-pressure mechanical seals.
Very recently Wang et al. [11] demonstrated experimentally a doubling of the load-carrying capacity for the surface- texture design by reactive ion etching of SiC parallel-thrust bearings sliding in water. These simple parallel thrust bearings are usually found in seal-less pumps where the pumped ?uid is used as the lubricant for the bearings. Due to the parallel sliding their performance is poorer than more sophisticated tapered or stepped bearings. Brizmer et al. [12] demon-strated the potential of laser surface texturing in the form of regular micro-dimples for providing load-carrying capacity with parallel-thrust bearings. A model of a textured parallel slider was developed and the e?ect of surface texturing on load-carrying capacity
was analyzed. The optimum parameters of the dimples were found in order to obtain maximum load-carrying capacity. A micro-dimple ??collective e?ect‘‘ was identi-
?ed that is capable of generating substantial load-carrying capacity, approaching that of optimumconventional thrust bearings. The purpose of the present paper is to investigate experimentally the validity of the model described in Ref. [12] by testing practical thrust bearings and comparing the performance of LST bearings with that of the theoretical predictions and with the performance of standard non-textured
bearings
2. Background
A cross section of the basic model that was analyzed in Ref. [12] is shown in figure
1. A slider having a width B is partially textured over a portion Bp =αB of its width. The
textured surface consists of multiple dimples with a diameter，depth and area density Sp. As a result of the hydrodynamic pressure generated by the dimples the sliding surfaces will be separated by a clearance depending on the sliding velocity U, the ?uid
viscosity l and the external load It was found in Ref. [12] that an optimum ratio exists
for the parameter that provides maximum dimensionless load-carrying capacity where L is
the bearing length, and this optimum value is hp=1.25. It was further found in Ref. [12] that an optimum value exists for the textured portion a depending onthe bearing aspect ratio L/B. This behavior is shown in ?gure 2 for a bearing with L/B = 0.75 at various values of the area density Sp. As can be seen in the range of Sp values from 0.18 to 0.72 the optimum a value varies from 0.7 to 0.55, respectively. It can also be seen from ?gure 2 that for a < 0.85 no optimum value exists for Sp and the maximum load W increases with increasing Sp. Hence, the largest area density that can be practically obtained with the laser texturing is desired. It is also interesting to note from ?gure 2 the advantage of partial-LST (a < 1) over the full LST (a = 1) for bearing applications. At Sp= 0.5, for example, the load W at a = 0.6 is about three times higher than its value at a = 1. A full account of this behavior is given in Ref. [12].
3. Experimental
The tested bearings consist of sintered SiC disks 10 mm thick, having 85 mm outer diameter and 40 mm inner diameter. Each bearing (see ?gure 3) comprises a ?at rotor (a) and a six-pad stator (b). The bearings were provided with an original surface ?nish
by lapping to a roughness average Ra= 0.03 lm. Each pad has an aspect ratio of 0.75 when its width is measured along the mean diameter of the stator. The photographs of two partial-LST stators are shown in ?gure 4 where the textured areas appear as brighter matt surfaces. The ?rst stator indicated (a) is a unidirectional bearing with the partial-LST adjacent to the leading edge of each pad, similar to the model shown in ?gure 1. The second stator (b) is a bi-directional version of a partial-LST bearing having two equal textured portions, a/2, on each of the pad ends. The laser texturing parameters were the following; dimple depth, dimple diameter
and dimple area density Sp= 0.60.03. These dimple dimensions were obtained with 4 pulses of 30 ns duration and 4 mJ each using a 5 kHz pulsating Nd:YAG laser. The textured portion of the unidirectional bearing was a= 0.73 and that of the bi-directional bearing was a= 0.63. As can be seen from ?gure 2 both these a values should produce load-carrying capacity vary close to the maximum theoretical value.The test rig is shown schematically in ?gure 5. An
electrical motor turns a spindle to which an upper holder of the rotor is attached. A second lower holder of the stator is ?xed to a housing, which rests on a journal bearing and an axial loading mechanism that can freely move in the axial direction
. An arm that presses against a load cell and thereby permits friction torque measurements prevents the free rotation of this housing. Axial loading is provided by means of dead weights on a lever and is measured with a second load cell. A proximity probe that is attached to the lower holder of the stator allows on-line measurements of the clearance change between rotor and stator as the hydrodynamic e?ects cause axial movement of the housing to which the stator holder is ?xed. Tap water is supplied by gravity from a large tank to the center of the bearing and the leakage from the bearing is collected and re-circulated. A thermocouple adjacent to
the outer diameter of the bearing allows monitoring of the water temperature as the water exit the bearing. A PC is used to collect and process data on-line. Hence,the instantaneous clearance, friction coe?cient, bearing speed and exit water temperature can be monitored constantly.
The test protocol includes identifying a reference ―zero‖point for the clearance measurements by ?rst loading and then unloading a stationary bearing over the full load range. Then the lowest axial load is applied, the water supply valve is opened and the motor turned on. Axial loading is increased by steps of 40 N and each load step is maintained for 5 min following the stabilization of the friction coe?cient at
a steady-state value. The bearing speed and water temperature are monitored throughout the test for any irregularities. The test ends when a maximum axial load of 460 N is reached or if the friction coe?cient exceeds a value of 0.35. At the end of the last load step the motor and water supply are turned o?and the reference for the clearance measurements is rechecked. Tests are performed at two speeds of 1500
and 3000 rpm corresponding to average sliding velocities of 4.9 and 9.8 m/s, respectively and each test is repeated at least three times.
4. Results and discussion
As a ?rst step the validity of the theoretical model in Ref. [12] was examined by comparing the theoretical and experimental results of bearing clearance versus bearing load for a unidirectional partial-LST bearing. The results are shown in ?gure 6 for the two speeds of 1500 and 3000 rpm where the solid and dashed lines correspond to the model and experiment, respectively. As can be seen, the agreement between the model and the experiment is good, with di?erences of less than 10%, as long as the load is above 150 N. At lower loads the measured experimental clearances are much larger than the model predictions, particularly at the higher speed of 3000 rpm where at 120 N the measured clearance is 20 lm, which is about 60% higher than the predicted value. It turns out that the combination of such large clearances and relatively low viscosity of the water may result in turbulent ?uid ?lm. Hence, the assumption of laminar ?ow on which the solution of the Reynolds equation in Ref. [12] is based may be violated making the model invalid especially at the higher speed and lowest load. In order to be consistent with the model of Ref. [12] it was decided to limit further comparisons to loads above 150 N.
It should be noted here that the ?rst attempts to test the baseline untextured bearing with the original surface ?nish of Ra= 0.03 lm on both the stator and rotor failed due to extremely high friction even at the lower loads. On the other hand the partial-LST bearing ran smoothly throughout the load range. It was found that the post-LST lapping to completely remove about 2 lm height bulges, which are formed during texturing around the rims of the dimples, resulted in a slightly rougher surface with Ra= 0.04 lm. Hence, the baseline untextured stator was also lapped to the same rough-
ness of the partial-LST stator and all subsequent tests were performed with the same Ra value of 0.04 lm for all the tested stators. The rotor surface roughness
remained, the original one namely, 0.03 lm. Figure 7 presents the experimental results for the clearance as a function of the load for a partial-LST unidirectional bearing (see stator in ?gure 4(a))and a baseline untextured bearing. The comparison is made at the two speeds of 1500 and 3000 rpm. The area density of the dimples in the partial-LST bearing is Sp= 0.6 and the textured portion is a ? 0:734. The load range extends from 160 to 460 N. The upper load was determined by the test-rig limitation that did not permit higher loading. It is clear from ?gure 7 that the partial-LST bearing operates at substantially larger clearances than the untextured bearing. At the maximum load of 460 N and speed of 1500 rpm the partial-LST bearing has a clearance of 6 lm while the untextured bearing clearance is only 1.7 lm. At 3000 rpm the clearances are 6.6
and 2.2 lm for the LST and untextured bearings, respectively. As can be seen from ?gure 7 this ratio of about 3 in favor of the partial-LST bearing is maintained over the entire load range.
Figure 8 presents the results for the bi-directionalbearing (see stator in ?gure 4(b)). In this case the LST parameters are Sp ?0:614 and a ?0:633. The clearances of the bi-directional partial-LST bearing are lower compared to these of the unidirectional bearing at the same load. At 460 N load the clearance for the 1500 rpm is 4.1 lm and for
the 3000 rpm it is 6 lm. These values represent a reduction of clearance between
33 and 10% compared to the unidirectional case. However, as can be seen from ?gure 8 the performance of the partial-LST bi-directional bearing is still substantially better than that of the untextured bearing.
The friction coe?cient of partial-LST unidirectional and bi-directional bearings was compared with that of the untextured bearing in ?gures 9 and 10 for the two speeds of 1500 and 3000 rpm, respectively. As can be seen the friction coe?cient of the two partial-LST bearings is very similar with slightly lower values in the case of the more e?cient unidirectional bearing. The friction coe?cient of the untextured bearing is much larger compared to that of the LST bearings. At 1500 rpm (?gure 9) and the highest load of 460 N the friction coe?cient of the untextured bearing is about 0.025 compared to about 0.01 for the LST bearings.
At the lowest load of 160 N the values are about 0.06 for the untextured bearing and around 0.02 for the LST bearings. Hence, the friction values of the untextured bearing are between 2.5 and 3 times higher than the corresponding values for the partial-LST bearings over the entire load range. Similar results were obtained at the velocity of 3000 rpm (?gure 10) but the level of the friction coe?cients is somewhat higher
due to the higher speed. The much higher friction of the untextured bearing is due to the much smaller clearances of this bearing (see ?gures 7 and 8) that result in higher viscous shear.
Bearings fail for a number of reasons，but the most common are misapplication，contamination，improper lubricant，shipping or handling damage，and misalignment. The problem is often not difficult to diagnose because a failed bearing usually leaves telltale
signs about what went wrong．
However，while a postmortem yields good information，it is better to avoid the process altogether by specifying the bearing correctly in The first place．To do this，it is useful to review the manufacturers sizing guidelines and operating characteristics for the selected bearing.
Equally critical is a study of requirements for noise, torque, and runout, as well as possible exposure to contaminants, hostile liquids, and temperature extremes. This can provide further clues as to whether a bearing is right for a job.
1 Why bearings fail
About 40% of ball bearing failures are caused by contamination from dust, dirt, shavings, and corrosion. Contamination also causes torque and noise problems, and is often the result of improper handling or the application environment．Fortunately, a bearing failure caused by environment or handling contamination is preventable，and a simple visual examination can easily identify the cause．
Conducting a postmortem il1ustrates what to look for on a failed or fa iling bearing．Then，understanding the mechanism behind the failure, such as brinelling or fatigue, helps eliminate the source of the problem.
Brinelling is one type of bearing failure easily avoided by proper handing and assembly. It is characterized by indentations in the bearing raceway caused by shock loading－such as when a bearing is dropped-or incorrect assembly. Brinelling usually occurs when loads exceed the material yield point(350,000 psi in SAE 52100 chrome steel)．It may also be caused by improper assembly, Which places a load across the races．Raceway dents also produce noise，vibration，and increased torque.
A similar defect is a pattern of elliptical dents caused by balls vibrating between raceways while the bearing is not turning．This problem is called false brinelling. It occurs on equipment in transit or that vibrates when not in operation. In addition, debris created by false brinelling acts like an abrasive, further contaminating the bearing. Unlike brinelling, false binelling is often indicated by a reddish color from fretting corrosion in the lubricant.
False brinelling is prevented by eliminating vibration sources and keeping the bearing well lubricated. Isolation pads on the equipment or a separate foundation may be required to reduce environmental vibration. Also a light preload on the bearing helps
keep the balls and raceway in tight contact. Preloading also helps prevent false brinelling during transit.
Seizures can be caused by a lack of internal clearance, improper lubrication, or excessive loading. Before seizing, excessive, friction and heat softens the bearing steel. Overheated bearings often change color，usually to blue-black or straw colored．Friction also causes stress in the retainer，which can break and hasten bearing failure．Premature material fatigue is caused by a high load or excessive preload．When these conditions are unavoidable，bearing life should be carefully calculated so that a maintenance scheme can be worked out．
Another solution for fighting premature fatigue is changing material．When standard bearing materials，such as 440C or SAE 52100，do not guarantee sufficient life，specialty materials can be recommended. In addition，when the problem is traced back to excessive loading，a higher capacity bearing or different configuration may be used．Creep is less common than premature fatigue．In bearings．it is caused by excessive clearance between bore and shaft that allows the bore to rotate on the shaft．Creep can be expensive because it causes damage to other components in addition to the bearing．0ther more likely creep indicators are scratches，scuff marks，or discoloration to shaft and bore．To prevent creep damage，the bearing housing and shaft fittings should be visually checked．
Misalignment is related to creep in that it is mounting related．If races are misaligned or cocked．The balls track in a noncircumferencial path．The problem is incorrect mounting or tolerancing，or insufficient squareness of the bearing mounting site．Misalignment of more than 1/4·can cause an early failure．
Contaminated lubricant is often more difficult to detect than misalignment or creep．Contamination shows as premature wear．Solid contaminants become an abrasive in the lubricant．In addition。insufficient lubrication between ball and retainer wears and weakens the retainer．In this situation，lubrication is critical if the retainer is a fully machined type．Ribbon or crown retainers，in contrast，allow lubricants to more easily reach all surfaces．
Rust is a form of moisture contamination and often indicates the wrong material for the application．If the material checks out for the job，the easiest way to prevent rust is to keep bearings in their packaging，until just before installation．
2 Avoiding failures
The best way to handle bearing failures is to avoid them．This can be done in the selection process by recognizing critical performance characteristics．These include noise，starting and running torque，stiffness，nonrepetitive runout，and radial and axial play．In some applications, these items are so critical that specifying an ABEC level alone is not sufficient．
Torque requirements are determined by the lubricant，retainer，raceway quality(roundness cross curvature and surface finish)，and whether seals or shields are used．Lubricant viscosity must be selected carefully because inappropriate lubricant，especially in miniature bearings，causes excessive torque．Also，different lubricants have varying noise characteristics that should be matched to the application. For example，greases produce more noise than oil．
Nonrepetitive runout(NRR)occurs during rotation as a random eccentricity between the inner and outer races，much like a cam action．NRR can be caused by retainer tolerance or eccentricities of the raceways and balls．Unlike repetitive runout, no compensation can be made for NRR.
NRR is reflected in the cost of the bearing．It is common in the industry to provide different bearing types and grades for specific applications．For example，a bearing with an NRR of less than 0.3um is used when minimal runout is needed，such as in disk—drive spindle motors．Similarly，machine—tool spindles tolerate only minimal deflections to maintain precision cuts．Consequently, bearings are manufactured with low NRR just for machine-tool applications．
Contamination is unavoidable in many industrial products，and shields and seals are commonly used to protect bearings from dust and dirt．However，a perfect bearing seal is not possible because of the movement between inner and outer races．Consequently，lubrication migration and contamination are always problems．
Once a bearing is contaminated, its lubricant deteriorates and operation becomes noisier．If it overheats，the bearing can seize．At the very least，contamination causes wear as it works between balls and the raceway，becoming imbedded in the races and acting as an abrasive between metal surfaces．Fending off dirt with seals and shields illustrates some methods for controlling contamination．
Noise is as an indicator of bearing quality．Various noise grades have been
developed to classify bearing performance capabilities．
Noise analysis is done with an Anderonmeter, which is used for quality control in bearing production and also when failed bearings are returned for analysis. A transducer is attached to the outer ring and the inner race is turned at 1,800rpm on an air spindle. Noise is measured in andirons, which represent ball displacement in μm/rad.
With experience, inspectors can identify the smallest flaw from their sound. Dust, for example, makes an irregular crackling. Ball scratches make a consistent popping and are the most difficult to identify. Inner-race damage is normally a constant high-pitched noise, while a damaged outer race makes an intermittent sound as it rotates.
Bearing defects are further identified by their frequencies. Generally, defects are separated into low, medium, and high wavelengths. Defects are also referenced to the number of irregularities per revolution.
Low-band noise is the effect of long-wavelength irregularities that occur about 1.6 to 10 times per revolution. These are caused by a variety of inconsistencies, such as pockets in the race. Detectable pockets are manufacturing flaws and result when the race is mounted too tightly in multiplejaw chucks.
Medium-hand noise is characterized by irregularities that occur 10 to 60 times per revolution. It is caused by vibration in the grinding operation that produces balls and raceways. High-hand irregularities occur at 60 to 300 times per revolution and indicate closely spaced chatter marks or widely spaced, rough irregularities.
Classifying bearings by their noise characteristics allows users to specify a noise grade in addition to the ABEC standards used by most manufacturers. ABEC defines physical tolerances such as bore, outer diameter, and runout. As the ABEC class number increase (from 3 to 9), tolerances are tightened. ABEC class, however, does not specify other bearing characteristics such as raceway quality, finish, or noise. Hence, a noise classification helps improve on the industry standard.
5. Conclusion
The idea of partial-LST to enhance performance of the parallel thrust bearing was evaluated experimentally. Good correlation was found with a theoretical model as
long as the basic assumption of laminar ?ow in the ?uid ?lm is valid. At low loads with relatively large clearances, where turbulence may occur, the experimental
clearance is larger than the prediction of the model.The performance of both
unidirectional and bidirectional partial-LST bearings in terms of clearance
and friction coe?cient was compared with that of a baseline untextured bearing over a load range in which the theoretical model is valid. A dramatic increase, of
about three times, in the clearance of the partial-LST bearings compared to that of the untextured bearing was obtained over the entire load range. Consequently the friction coe?cient of the partial-LST bearings is much lower, representing more than 50% reduction in friction compared to the untextured bearing.
The larger clearance and lower friction make the partial-LST simple parallel thrust bearing concept much more reliable and e?cient especially in seal-less pumps and similar applications where the process ?uid, which is o ften a poor lubricant, is the only available lubricant for the bearings.
Acknowledgments
The authors would like to thank Mr. J. Boylan of Morgan AM&T for providing the bearing specimens and Mr. N. Barazani of Surface Technologies Ltd. For providing the laser surface texturing.
实验研究激光加工表面微观造型平行的推力轴承实验是研究激光处理的表面微观造型平行的推力轴承增强的某些性能。测试结果与理论模型进行了比较,，发现在有关的运行条件之外有着别的关系。突出表现在，单向和双向定向部分反演轴承与一个基线的关系，激光表面微观造型与无微观造型轴承的比较显示好处在于，增加了清理和减少摩擦。
关键词：油膜轴承，滑块，轴承，表面微观造型
绪论
经典理论的流体动力润滑产生线性（couette ）的速度分布与零压力梯度之间的顺利进行平行表面下的稳定状态滑动。这个结果在不稳定的润滑膜在任何外部力在表面起作用的情况下会破裂。不过，经验表明，稳定的润滑膜可以扩大他们之间的平行滑动面，一般由于某些机制，放宽一种或一种以上的对经典理论的假设。
在平行滑动面可以得到一个稳定的，有足够的承载能力的油膜，例如，宏观或微观表面结构就是不同类型。这些措施包括波纹形[ 1 ]和凸起微粗糙面[ 2-4 ]。一个好的工艺系统就是一个标准[ 5 ] 。最近，激光表面纹理[ 6-8 ] ，就是开口粗糙的纵向或横向的凹槽[ 9 ]在平行滑动提供承载能力。开口粗糙度的概念既[ 9 ]是基于有效地清除，减少在滑动方向和在这方面是相同的部分激光表面微造型概念所描述的标准。[ 10 ]产生静压力对高压力的机械密封影响。最近，王等人。[ 11 ]实验表明，增加一倍的承载能力为表面纹理设计的反应离子刻蚀碳化硅平行推力轴承滑动在水中。这些简单的平行推力轴承，通常发现，在密封泵少的地方抽液是用来作为润滑
剂的轴承。由于平行滑动他们的表现较差，比更先进的锥形或加强轴承。brizmer等人。[ 12 ]表现出的潜力，激光表面纹理在的形式，定期微量波纹提供承载能力与平行推力轴承。模型的纹理平行滑块是发达国家和作用的表面纹理对承载能力进行了分析。最佳参数的微波被发现，以取得最大的承载能力。微蜂窝集体效应被鉴定是能产生可观的承载能力，接近的最佳的传统推力轴承。该本文件的目的是调查实验模型的有效性所描述的档号。[ 12 ]通过测试的实际推力轴承且与没有表面微观造型的轴承比较，表现反演轴承与该理论预测与性能标准的差异。
第二章背景
基本模型的横截面用标准分析了[ 12 ]是表现在图1。滑块有一个宽度B是部分微
观造型BP = αB的宽度。该纹理的表面组成众多波纹同一的直径为深度为分布密度为自身属性。人们发现，有着微观表面造型的滑动面的油压被分开是与滑动速度U、液体粘度1和外部负载W有关[ 12 ]认为，有一个最佳的比例参数
存在能使微观表面造型提供最大的无量纲负载
。其中L是轴承的长度，且最浩的动力是HP=1.25.
这是进一步发现，[ 12 ]认为，部分的表面微观造型存在一个最佳值为轴承长宽比L/B这种行为是如图2所示为轴承b = 0.75在不同的价值观该地区的密度藻可以看出，在从0.18至0.72范围内发现SP值的最佳值不同，分别从0.7至0.55 。它也可以从图2 ，对于一个0.85<密度是没有最优值的SP存在且最高负荷瓦特与SP同步增加，因此，最大的面积密度，可以得到几乎与激光毛化是理想的。这亦是有趣地注意到，从图2，我们看到用软件仿真的部分表面微观造型的优势。举例说明，在SP=0.5比例α=0.6时是α=1时的三倍的的承载能力。
第三章实验
测试轴承组成烧结碳化硅磁盘10毫米厚，有八十五毫米外径和40毫米内径。每个轴承（见图3 ）组成一个单位，转子（a ）和6垫定子（b ）款。轴承提供了一个原始的表面光洁度
由研磨到平均粗糙度在Ra = 0.03的LM 。每个垫有一个长宽比0.75时，其宽度是衡量沿线平均直径定子。照片2部分第1定子是如图4所示的地方纹理地区出现更加美好的亚光表面。第一定子表示，（ a ）是单向轴承与局部反演毗邻的领先地位，每个垫，类似的模型如图1所示。第二定子（二）是一个双向定向版本的部分反演轴承
有两个平等的纹理部分1/2，对每一项垫结束。该激光毛化参数以下;压痕深度
，压痕直径和压痕面积密度sp = 0.6 0.03 。这些压痕的尺寸，获得了与4脉冲30的NS的时间长短和4兆焦耳每使用1 5千赫的脉动Nd ：YAG激光。该纹理部分单向轴承是一个= 0.73和该双向定向轴承是一个= 0.63 。可以看出，从图2这两种价值观应产生承载能力不同，接近最高的理论value.the试验台是显示schematically在图5 。电机轮流主轴，以其中一上持有转子重视。第二个较低的持有人的定子是固定的房屋，在于对滑动轴承和一个轴向加载机制，在轴线方向可以自由走动。
一个单臂反应压力与负载单元相互作用，从而许可证的摩擦力矩测量阻止自由旋转这个机架。轴向载荷是所提供的手段，对绝对的权重杠杆作用，是衡量一个第二负荷单元。感应探头是附加到较低的持有人的定子，让上线的测量清拆变化之间的转子和定子由于水动力影响的原因轴向运动的房屋，其中定子持有人，这是一个固定的。自来水供应的重心从一个大罐的中心轴承和渗漏从轴承是收集和重新分发。1热电偶毗邻
外径轴承允许监测水温，作为水出口轴承。电脑是用来收集和处理数据上线。因此，瞬时关，摩擦系数，轴承的速度和开槽的温度可不断监测。
测试草案包括确定一个参考―零‖点为清除测量第一有负载和无负载，然后固定轴承超过满负荷的范围。然后最低的轴向载荷应用，供水阀打开及汽车开启。轴向负荷增加的步骤40 N和每个负载的步骤是维持5分钟之后，稳定的摩擦系数在一稳定状态的价值。轴承的速度和水温监测整个测试的任何违规行为。试验结束时，最大轴向负荷460 N是达到或如果摩擦系数超过了价值0.35 。在年底的最后一步负荷电机及食水供应关掉，并参考有关清拆测量是复查。测试是在两种速度的1500 和3000 RPM的相应的平均滑动速度4.9和9.8米/秒，分别和每个测试重复至少3次
第四章成果与讨论
作为第一步的有效性的理论模型。[ 12 ]研究并比较，理论和实验结果的轴承
间隙银两轴承载荷为单向局部反演轴承。结果表明，在图6为两种速度的1500和3000 rpm的情况下固体和虚线对应到模型和实验，分别。可以看出，双方间的协议模型和实验是好的，与不同的不到10 ％，只要负荷是150以上的12月31日在较低载荷测量的实验清拆要远远大于模型预测，尤其是在较高的速度，3000 rpm的情况下，在120 n实测关是20的LM ，这是约60 ％，高于预测值。结果表明，该组合，如此庞大的间隙和相对低粘度的水可能会导致湍流流体膜。因此，假设油膜上，解决这一雷诺方程的标准形式。[ 12 ]是基于可能违反决策模型无效特别是在较高的速度和最低的负荷。[ 12 ]这是决定进一步限制比较负荷以上150 N
它这里应该指出，第一，企图测试基线无微观造型轴承与原来的表面光洁度的RA = 0.03的LM上都定子和转子失败，由于极高的摩擦，甚至在较低的负荷。在另一方面部分-第1轴承，整个负荷范围顺利。结果发现，后反演研磨完全移除约2的LM高度凸出部分，这是中形成的纹理周围的轮辋的波纹，导致在一个稍微粗糙的表面粗糙度= 0.04的LM 。因此，基线与无造型的定子重叠，以同一粗糙性的部分-第1定子和其后所有测试的表现与定子同在Ra值为0.04的LM的所有测试。转子表面粗糙度仍然存在，原因，即0.03的LM 。图7给出了实验结果为清除作为一个功能负荷为局部反演单向轴承（见定子在图4 （ a ））和基线无微观造型轴承。比较是在两种速度的1500和3000 RPM的。面密度的波纹在部分-第1轴承是sp = 0.6和纹理部分是一个6.3 0:734 。该负荷范围扩大，从160至460 12月31日上负载检测试验台的限制，不容许较高的负荷。很显然，从图7部分-第1轴承运转大幅清拆比无微观造型轴承。在最高负荷460 N和速度1500 RPM的部分-第1轴承已清拆6的LM ，而无微观造型轴承间隙是只有1.7的LM 。在3000 RPM的清拆是6.6 和2.2的LM为第1和无微观造型轴承，分别。可以看出，从图7 ，这个比例约三倍，赞成部分-第1轴承是保持在整个负荷范围。
图8给出的结果为双向轴承（见定子在图4 （ b ）款）。在这种情况下，反演参数sp=6.3 α=0.614和0.633 6.3 。清拆的双向定向部分反演轴承相比，降低这些的
单向轴承在同一负荷。在460 n负载清拆为1500 rpm的是4.1 LM和为3000 rpm的，这是6月的LM 。这些价值观所代表的减少之间的关
33和10 ％相比，单向的情况。不过，可以看出，从图8的表现，部分-第1双向定向轴承仍是大大优于该无微观造型轴承。
图10为两种速度分别是1500和3000 rpm。可以看出，摩擦系数的两个部分反演轴承是非常类似的与略低的价值观，在部件较有高效率的单向轴承。无微观造型的的摩擦系数大得多比他们大的多，即第1轴承。在1500 RPM的（图9 ）和最高负荷460 n 摩擦系数的untextured轴承是约0.025相比，约为第1轴承0.01。
在最低负荷160 n值约0.06为无微观造型轴承的为第1轴承的0.02左右。因此，无微观造型轴承摩擦值，高于相应值为局部反演轴承在整个负荷范围的2.5和3倍。，在速度上获得了类似的结果，3000每分钟转速（图10 ），但水平的摩擦系数是有点高，由于较高的速度。无微观造型轴承的摩擦高得多，是因为无小槽清理磨砂（见图7和图8），导致较高的粘性剪切。
导致轴承失效的原因很多，但常见的是不正确的使用、污染、润滑剂使用不当、装卸或搬运时的损伤及安装误差等。诊断失效的原因并不困难，因为根据轴承上留下的痕迹可以确定轴承失效的原因。
然而，当事后的调查分析提供出宝贵的信息时，最好首先通过正确地选定轴承
AT89C51的概况 The General Situation of AT89C51 Chapter 1 The application of AT89C51 Microcontrollers are used in a multitude of commercial applications such as modems, motor-control systems, air conditioner control systems, automotive engine and among others. The domains also require that these microcontrollers are be ensured by a robust testing process and a proper tools environment for the validation of these microcontrollers both at the component and at the system level. Intel Plaform Engineering department developed an object-oriented multi-threaded test environment for the validation of its AT89C51 automotive microcontrollers. The goals of thisenvironment was not only to provide a robust testing environment for the AT89C51 automotive microcontrollers, but to develop an environment which can be easily extended and reused for the validation of several other future microcontrollers. The environment was developed in conjunction with Microsoft Foundation Classes (AT89C51). The paper describes the design and mechanism of this test environment, its interactions with various The 8-bit AT89C51 CHMOS microcontrollers are designed to engine-control systems, airbags, suspension systems, and antilock braking systems (ABS). The AT89C51 is especially well suited to applications that benefit from its processing speed and enhanced
外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华
外文资料名称： Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处：Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件： 1.外文资料翻译译文 2.外文原文
应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金，洪城铱昌，宰瑾李， 刘链柱译 摘要：旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率，压降，并切成尺寸被粒度对应于分级收集的50％的效率进行了研究。颗粒切成大小降低入口面积，体直径，减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法，用于收集在家庭中产生的粉尘。 摘要及关键词：吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子，工作场所，或其他建筑，因此，室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物，毒物，食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤，预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中，吸入压力下降说唱空转成比例地清洗的时间，以及纸过滤器也应定期更换，由于压力下降，气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形，在粗颗粒（>2.0微米）模式为主要的外部来源，如风吹尘，海盐喷雾，火山，从工厂直接排放和车辆废气排放，以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式，典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克，可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。
毕业设计（论文）外文文献翻译 文献、资料中文题目：软件开发概念和设计方法文献、资料英文题目： 文献、资料来源： 文献、资料发表（出版）日期： 院（部）： 专业： 班级： 姓名： 学号： 指导教师： 翻译日期： 2017.02.14
外文资料原文 Software Development Concepts and Design Methodologies During the 1960s, ma inframes and higher level programming languages were applied to man y problems including human resource s yste ms,reservation s yste ms, and manufacturing s yste ms. Computers and software were seen as the cure all for man y bu siness issues were some times applied blindly. S yste ms sometimes failed to solve the problem for which the y were designed for man y reasons including: ?Inability to sufficiently understand complex problems ?Not sufficiently taking into account end-u ser needs, the organizational environ ment, and performance tradeoffs ?Inability to accurately estimate development time and operational costs ?Lack of framework for consistent and regular customer communications At this time, the concept of structured programming, top-down design, stepwise refinement，and modularity e merged. Structured programming is still the most dominant approach to software engineering and is still evo lving. These failures led to the concept of "software engineering" based upon the idea that an engineering-like discipl ine could be applied to software design and develop ment. Software design is a process where the software designer applies techniques and principles to produce a conceptual model that de scribes and defines a solution to a problem. In the beginning, this des ign process has not been well structured and the model does not alwa ys accurately represent the problem of software development. However,design methodologies have been evolving to accommo date changes in technolog y coupled with our increased understanding of development processes. Whereas early desig n methods addressed specific aspects of the
使用高级分析法的钢框架创新设计 1．导言 在美国，钢结构设计方法包括允许应力设计法(ASD)，塑性设计法(PD)和荷载阻力系数设计法(LRFD)。在允许应力设计中，应力计算基于一阶弹性分析，而几何非线性影响则隐含在细部设计方程中。在塑性设计中，结构分析中使用的是一阶塑性铰分析。塑性设计使整个结构体系的弹性力重新分配。尽管几何非线性和逐步高产效应并不在塑性设计之中，但它们近似细部设计方程。在荷载和阻力系数设计中，含放大系数的一阶弹性分析或单纯的二阶弹性分析被用于几何非线性分析，而梁柱的极限强度隐藏在互动设计方程。所有三个设计方法需要独立进行检查，包括系数K计算。在下面，对荷载抗力系数设计法的特点进行了简要介绍。 结构系统内的内力及稳定性和它的构件是相关的，但目前美国钢结构协会（AISC）的荷载抗力系数规范把这种分开来处理的。在目前的实际应用中，结构体系和它构件的相互影响反映在有效长度这一因素上。这一点在社会科学研究技术备忘录第五录摘录中有描述。 尽管结构最大内力和构件最大内力是相互依存的（但不一定共存），应当承认，严格考虑这种相互依存关系，很多结构是不实际的。与此同时，众所周知当遇到复杂框架设计中试图在柱设计时自动弥补整个结构的不稳定（例如通过调整柱的有效长度）是很困难的。因此，社会科学研究委员会建议在实际设计中，这两方面应单独考虑单独构件的稳定性和结构的基础及结构整体稳定性。图28.1就是这种方法的间接分析和设计方法。
在目前的美国钢结构协会荷载抗力系数规范中，分析结构体系的方法是一阶弹性分析或二阶弹性分析。在使用一阶弹性分析时，考虑到二阶效果，一阶力矩都是由B1,B2系数放大。在规范中，所有细部都是从结构体系中独立出来，他们通过细部内力曲线和规范给出的那些隐含二阶效应，非弹性，残余应力和挠度的相互作用设计的。理论解答和实验性数据的拟合曲线得到了柱曲线和梁曲线，同时Kanchanalai发现的所谓“精确”塑性区解决方案的拟合曲线确定了梁柱相互作用方程。 为了证明单个细部内力对整个结构体系的影响，使用了有效长度系数，如图28.2所示。有效长度方法为框架结构提供了一个良好的设计。然而，有效长度方法的
1. Introduction America is one of the countries that speak English. Because of the special North American culture, developing history and the social environment, American English has formed its certain unique forms and the meaning. Then it turned into American English that has the special features of the United States. American English which sometimes also called United English or U.S English is the form of the English language that used widely in the United States .As the rapid development of American economy, and its steady position and strong power in the world, American English has become more and more widely used. As in 2005, more than two-thirds of English native speakers use various forms of American English. The philologists of the United States had divided the English of the United States into four major types: “America n creating”; “Old words given the new meaning”; “Words that eliminated by English”;“The phonetic foreign phrases and the languages that are not from the English immigrates”[1]. Compared to the other languages, American English is much simple on word spelling, usage and grammar, and it is one of the reasons that American English is so popular in the world. The thesis analyzes the differences between American English and British English. With the main part, it deals with the development of American English, its peculiarities compared to that of British English, its causes and tendency. 2. Analyses the Differences As we English learners, when we learning English in our junior or senior school, we already came across some words that have different spellings, different pronunciations or different expressions, which can be represented by following contrasted words: spellings in "color" vs. "colour"; pronunciations in "sec-re-ta-ry" vs. "sec-re-try";
Advantages of Managed Code Microsoft intermediate language shares with Java byte code the idea that it is a low-level language witha simple syntax , which can be very quickly translated intonative machine code. Having this well-defined universal syntax for code has significant advantages. Platform independence First, it means that the same file containing byte code instructions can be placed on any platform; atruntime the final stage of compilation can then be easily accomplished so that the code will run on thatparticular platform. In other words, by compiling to IL we obtain platform independence for .NET, inmuch the same way as compiling to Java byte code gives Java platform independence. Performance improvement IL is actually a bit more ambitious than Java bytecode. IL is always Just-In-Time compiled (known as JIT), whereas Java byte code was ofteninterpreted. One of the disadvantages of Java was that, on execution, the process of translating from Javabyte code to native executable resulted in a loss of performance. Instead of compiling the entire application in one go (which could lead to a slow start-up time), the JITcompiler simply compiles each portion of code as it is called (just-in-time). When code has been compiled.once, the resultant native executable is stored until the application exits, so that it does not need to berecompiled the next time that portion of code is run. Microsoft argues that this process is more efficientthan compiling the entire application code at the start, because of the likelihood that large portions of anyapplication code will not actually be executed in any given run. Using the JIT compiler, such code willnever be compiled.
南京理工大学 毕业设计(论文)外文资料翻译 教学点：南京信息职业技术学院 专业：电子信息工程 姓名：陈洁 学号： 014910253034 外文出处：《 Pci System Architecture 》 (用外文写) 附件： 1.外文资料翻译译文；2.外文原文。 指导教师评语： 该生外文翻译没有基本的语法错误，用词准确，没 有重要误译，忠实原文；译文通顺，条理清楚，数量与 质量上达到了本科水平。 签名： 年月日 注：请将该封面与附件装订成册。
附件1：外文资料翻译译文 64位PCI扩展 1.64位数据传送和64位寻址：独立的能力 PCI规范给出了允许64位总线主设备与64位目标实现64位数据传送的机理。在传送的开始，如果回应目标是一个64位或32位设备，64位总线设备会自动识别。如果它是64位设备，达到8个字节（一个4字）可以在每个数据段中传送。假定是一串0等待状态数据段。在33MHz总线速率上可以每秒264兆字节获取（8字节／传送＊33百万传送字／秒），在66MHz总线上可以528M字节／秒获取。如果回应目标是32位设备，总线主设备会自动识别并且在下部4位数据通道上（AD[31::00]）引导，所以数据指向或来自目标。 规范也定义了64位存储器寻址功能。此功能只用于寻址驻留在4GB地址边界以上的存储器目标。32位和64位总线主设备都可以实现64位寻址。此外，对64位寻址反映的存储器目标（驻留在4GB地址边界上）可以看作32位或64位目标来实现。 注意64位寻址和64位数据传送功能是两种特性，各自独立并且严格区分开来是非常重要的。一个设备可以支持一种、另一种、都支持或都不支持。 2.64位扩展信号 为了支持64位数据传送功能，PCI总线另有39个引脚。 ●REQ64#被64位总线主设备有效表明它想执行64位数据传送操作。REQ64#与FRAME#信号具有相同的时序和间隔。REQ64#信号必须由系统主板上的上拉电阻来支持。当32位总线主设备进行传送时，REQ64#不能又漂移。 ●ACK64#被目标有效以回应被主设备有效的REQ64#（如果目标支持64位数据传送），ACK64#与DEVSEL#具有相同的时序和间隔（但是直到REQ64#被主设备有效，ACK64#才可被有效）。像REQ64#一样，ACK64#信号线也必须由系统主板上的上拉电阻来支持。当32位设备是传送目标时，ACK64#不能漂移。 ●AD[64::32]包含上部4位地址／数据通道。 ●C/BE#[7::4]包含高4位命令/字节使能信号。 ●PAR64是为上部4个AD通道和上部4位C/BE信号线提供偶校验的奇偶校验位。 以下是几小结详细讨论64位数据传送和寻址功能。 3.在32位插入式连接器上的64位卡
理工学院毕业设计(论文)外文资料翻译 专业：热能与动力工程 姓名：赵海潮 学号：09L0504133 外文出处：Applied Acoustics, 2010(71):701~707 附件： 1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文 基于一维CFD模型下汽车排气消声器的实验研究与预测Takeshi Yasuda, Chaoqun Wua, Noritoshi Nakagawa, Kazuteru Nagamura 摘要目前，利用实验和数值分析法对商用汽车消声器在宽开口喉部加速状态下的排气噪声进行了研究。在加热工况下发动机转速从1000转/分钟加速到6000转/分钟需要30秒。假定其排气消声器的瞬时声学特性符合一维计算流体力学模型。为了验证模拟仿真的结果，我们在符合日本工业标准（JIS D 1616）的消声室内测量了排气消声器的瞬态声学特性，结果发现在二阶发动机转速频率下仿真结果和实验结果非常吻合。但在发动机高阶转速下（从5000到6000转每分钟的四阶转速，从4200到6000转每分钟的六阶转速这样的高转速范围内），计算结果和实验结果出现了较大差异。根据结果分析，差异的产生是由于在模拟仿真中忽略了流动噪声的影响。为了满足市场需求，研究者在一维计算流体力学模型的基础上提出了一个具有可靠准确度的简化模型，相对标准化模型而言该模型能节省超过90％的执行时间。 关键字消声器排气噪声优化设计瞬态声学性能 1 引言 汽车排气消声器广泛用于减小汽车发动机及汽车其他主要部位产生的噪声。一般而言，消声器的设计应该满足以下两个条件：（1）能够衰减高频噪声，这是消声器的最基本要求。排气消声器应该有特定的消声频率范围，尤其是低频率范围，因为我们都知道大部分的噪声被限制在发动机的转动频率和它的前几阶范围内。（2）最小背压，背压代表施加在发动机排气消声器上额外的静压力。最小背压应该保持在最低限度内，因为大的背压会降低容积效率和提高耗油量。对消声器而言，这两个重要的设计要求往往是互相冲突的。对于给定的消声器，利用实验的方法，根据距离尾管500毫米且与尾管轴向成45°处声压等级相近的排气噪声来评估其噪声衰减性能，利用压力传感器可以很容易地检测背压。 近几十年来，在预测排气噪声方面广泛应用的方法有：传递矩阵法、有限元法、边界元法和计算流体力学法。其中最常用的方法是传递矩阵法（也叫四端网络法）。该方
（ 本科毕业设计外文文献翻译 学校代码： 10128 学 号： 题 目：Shear wall structural design of high-level framework 学生姓名： 学 院：土木工程学院 系 别：建筑工程系 专 业：土木工程专业（建筑工程方向） 班 级：土木08-（5）班 指导教师： (副教授)
Shear wall structural design of high-level framework Wu Jicheng Abstract: In this paper the basic concepts of manpower from the frame shear wall structure, analysis of the structural design of the content of the frame shear wall, including the seismic wall shear span ratio design, and a concrete structure in the most commonly used frame shear wall structure the design of points to note. Keywords: concrete; frame shear wall structure; high-rise buildings The wall is a modern high-rise buildings is an important building content, the size of the frame shear wall must comply with building regulations. The principle is that the larger size but the thickness must be smaller geometric features should be presented to the plate, the force is close to cylindrical. The wall shear wall structure is a flat component. Its exposure to the force along the plane level of the role of shear and moment, must also take into account the vertical pressure. Operate under the combined action of bending moments and axial force and shear force by the cantilever deep beam under the action of the force level to look into the bottom mounted on the basis of. Shear wall is divided into a whole wall and the associated shear wall in the actual project, a whole wall for example, such as general housing construction in the gable or fish bone structure film walls and small openings wall. Coupled Shear walls are connected by the coupling beam shear wall. But because the
故障概率模型的数控车床 摘要：领域的失效分析被计算机数字化控制（CNC）车床描述。现场收集了为期两年的约80台数控车床的故障数据。编码系统代码失效数据是制定和失效分析数据库成立的数控车床。失败的位置和子系统，失效模式及原因进行了分析，以显示薄弱子系统的数控车床。另外，故障的概率模型，分析了数控车床的模糊多准则综合评价。 作者关键词：数控车床；场失败；概率模型；模糊信息 文章概述 1.介绍 2. CNC车床的概述 3.收集和整理数据 3.1. 收集数据 3.2. 领域失效数据的有效性 3.3. 数据核对和数据库 4. 失效分析 4.1. 对失败位置和子系统的频率分析 4.2. 对失败形式的频率分析 5.失败机率模型 5.1. 方法学 5.2. 分布倍之间连续的失败 5.3. 修理时间的发行 6.结论 1.介绍 在过去十年中，计算机数字化控制（CNC）车床已经越来越多地被引入到机械加工过程中。由于其固有的灵活性很大，稳定的加工精度和高生产率，数控车床是能给用户巨大的利益。然而，作为一个单一的数控车床故障也许会导致整个生产车间被停止，而且维修更加困难和昂贵，当故障发生时[1]，数控车床能够给用户带来很多的麻烦。 与此同时，制造商还需要持续改进数控车床的可靠性来提高市场的竞争力。因此，数控车床的可靠性能使生产商和用户增加显著性和至关重要的意义。 需要改进数控车床的可靠性，使用户和制造商收集和分析领域的故障数据和采取措施减少停机时间。本文论述了研究失效模式及原因，失效的位置和薄弱的子系统，故障概率模型的数控车床。
图1 系统框图的数控车床 机械系统包括主轴及其传动链（固定在主轴箱），两根滑动轴（命名X、Z或者U，W在轮），车床拖板箱，转动架或刀架，尾座，床身等。主轴持续或加强连续变速，驱动交流或直流主轴电机直接或通过主传动，并有一个光电编码器的主轴车削螺纹。X和Z 两根轴的驱动交流或直流伺服车削螺纹和控制同时进行。该转动架或刀架可自动交换工
长江大学工程技术学院 毕业设计（论文）外文翻译 外 文 题 目 Matlab Based Interactive Simulation Program for 2D Multisegment Mechanical Systems 译 文 题 目 二维多段机械系统基于Matlab 的 交互式仿真程序 系 部 化学工程系 专 业 班 级 化工60801 学 生 姓 名 李泽辉 指 导 教 师 张 铭 辅 导 教 师 张 铭 完 成 日 期 2012.4.15 顶层配置在管路等，要求设备，所有设要求，对调整使案，编是指机确保机组中资料试
外文翻译 二维多段机械系统基于Matlab 的交互式仿真程序 Henryk Josiński, Adam ?witoński, Karol J?drasiak 著；李泽辉 译 摘要：本文介绍了多段机械系统设计原则，代表的是一个模型的一部分的设计系统，然后扩展 形成的几个部分和模型算法的分类与整合的过程，以及简化步骤的过程叫多段系统。本文还介绍了设计过程的二维多段机械系统的数字模型，和使用Matlab 的软件包来实现仿真。本文还讨论测试运行了一个实验，以及几种算法的计算，实现了每个单一步骤的整合。 1 简介 科学家创造了物理模型和数学模型来表示人类在运动中的各种形式。数学模型 使创建数字模型和进行计算机仿真成为可能。模型试验，可以使人们不必真正的实 验就可以虚拟的进行力和力矩的分解。 本文研究的目的是建立一个简单的多段运动模型，以增加模型的连续性和如何 避免不连续为原则。这是创建一个人类运动模型系统的冰山一角。其使用matlab 程 序包创建的数字模型，可以仿真人类运动。 文献中关于这一主题的内容很广泛。运动的模式和力矩的分解在这些文献中都 有涉猎。动态的平面人体运动模型，提出了解决了迭代矩阵的方法。还值得一提的 是这类项目的参考书目，布鲁贝克等人提出了一个模型——人腿模型，这个以人的 物理运动为基础的平面模型仿真了人腿——一个单一的扭簧和冲击碰撞模型。人腿 模型虽然简单，但是它展示人类的步态在水平地面上的运动特征。布鲁贝克等人还 介绍，在人腿模型的双足行走的基础上，从生物力学的角度而言，符合人体步行的 特征。这个模型具有一个躯干，双腿膝盖和脚踝。它能够合理的表现出人多样的步 态风格。一个仿真人类运动的数学模型反应出了人的部分运动状态。 图1. 力的分解 2 力的分解
Highway Subgrade Construction in Expansive Soil Areas Jian-Long Zheng1 Rui Zhang2 and He-Ping Yang3 1 Professor and President, ChangSha Univ. of Science and Technology, Chiling Road 45, Changsha, Hunan 410076, China. E-mail: zjl_csust@https://www.doczj.com/doc/4a1728014.html, 2 Ph.D. Candidate and Lecturer, School of Highway Engineering, ChangSha Univ. of Science and Technology, Chiling Road 45, Changsha, Hunan 410076, China. E-mail: zr_csust@https://www.doczj.com/doc/4a1728014.html, 3Professor, School of Highway Engineering, ChangSha Univ. of Science and Technology, Chiling Road 45, Changsha, Hunan 410076, China. E-mail: cscuyang@https://www.doczj.com/doc/4a1728014.html, (Accepted 22 May 2007) Introduction Expansive soil is predominantly clay soil that undergoes appreciable volume and strength changes following a change in moisture content. These volume changes can cause extensive damage to the geotechnical infrastructure, and the damage is often repeatable and latent in the long term (Liao 19848). China is one of the countries with a wide distribution of expansive soils. They are found in more than 20 provinces and regions, nearly 600,000?km2in extent. It has been estimated that the planned highways totaling 3,300?km in length pass through expansive soils areas (Zheng and Yang 200422). Improper highway construction in such areas could well lead to great losses and damage to the environment. In 2002, the Chinese Ministry of Communications (CMOC) sponsored a research project, “A Complete Package for Highway Construction in Expansive Soil Areas,” whose primary objective was to solve expansive soil problems in highway engineering. A research group with personnel from Changsha University of Science and Technology (CUST) was set up. Comprehensive laboratory tests, field investigations, and analyses were carried out, aimed at solving highway engineering problems in several different expansive soil areas. A complete presentation of the results of this research is beyond the scope of this paper, but the research on subgrade
青岛大学 毕业论文(设计)科技文献翻译 院系：自动化工程学院控制工程系 专业：自动化 班级：2009级4班 姓名：史发涛 指导教师：于金鹏 2013年4月10日
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