英文资料
Suspension
Suspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. Suspension systems serve a dual purpose –contributing to the car's roadholding/handling and braking for good active safety and driving pleasure, and keeping vehicle occupants comfortable and reasonably well isolated from road noise, bumps, and vibrations,etc. These goals are generally at odds, so the tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the forces acting on the vehicle do so through the contact patches of the tires. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different.
Leaf springs have been around since the early Egyptians.
Ancient military engineers used leaf springs in the form of bows to power their siege engines, with little success at first. The use of leaf springs in catapults was later refined and made to work years later. Springs were not only made of metal, a sturdy tree branch could be used as a spring, such as with a bow.
Horse drawn vehicles
By the early 19th century most British horse carriages were equipped with springs; wooden springs in the case of light one-horse vehicles to avoid taxation, and steel springs in larger vehicles. These were made of low-carbon steel and usually took the form of multiple layer leaf springs.[1]
The British steel springs were not well suited for use on America's rough roads of the time, and could even cause coaches to collapse if cornered too fast. In the 1820s, the Abbot Downing Company of Concord, New Hampshire developed a system whereby the bodies of stagecoaches were supported on leather straps called "thoroughbraces", which gave a swinging motion instead of the jolting up and down of a spring suspension (the stagecoach itself was sometimes called a "thoroughbrace")
Automobiles
Automobiles were initially developed as self-propelled versions of horse drawn vehicles. However, horse drawn vehicles had been designed for relatively slow speeds and their suspension was not well suited to the higher speeds permitted by the internal combustion engine.
In 1903 Mors of Germany first fitted an automobile with shock absorbers. In 1920 Leyland used torsion bars in a suspension system. In 1922 independent front suspension was pioneered on the Lancia Lambda and became more common in mass market cars from 1932.[2]
Important properties
Spring rate
The spring rate (or suspension rate) is a component in setting the vehicle's ride height or its location in the suspension stroke. Vehicles which carry heavy loads will often have heavier springs to compensate for the additional weight that would otherwise collapse a vehicle to the bottom of its travel (stroke). Heavier springs are also used in performance applications where the loading conditions experienced are more extreme. Springs that are too hard or too soft cause the suspension to become ineffective because they fail to properly isolate the vehicle from the road. Vehicles that commonly experience suspension loads heavier than normal have heavy or hard springs with a spring rate close to the upper limit for that vehicle's weight. This allows the vehicle to perform properly under a heavy load when control is limited by the inertia of the load. Riding in an empty truck used for carrying loads can be uncomfortable for passengers because of its high spring rate relative to the weight of the vehicle. A race car would also be described as having heavy springs and would also be uncomfortably bumpy. However, even though we say they both have heavy springs, the actual spring rates for a 2000 lb race car and a 10,000 lb truck are very different. A luxury car, taxi, or passenger bus would be described as having soft springs. Vehicles with worn out or damaged springs ride lower to the ground which reduces the overall amount of compression available to the suspension and increases the amount of body lean. Performance vehicles can sometimes have spring rate requirements other than vehicle weight and load.
Mathematics of the spring rate
Spring rate is a ratio used to measure how resistant a spring is to being compressed or expanded during the spring's deflection. The magnitude of the spring force increases as deflection increases according to Hooke's Law. Briefly, this can be stated as
where
F is the force the spring exerts
k is the spring rate of the spring.
x is the displacement from equilibrium length i.e. the length at which the spring is neither compressed or stretched.
Spring rate is confined to a narrow interval by the weight of the vehicle,load the vehicle will carry, and to a lesser extent by suspension geometry and performance desires.
Spring rates typically have units of N/mm (or lbf/in). An example of a linear spring rate is 500 lbf/in. For every inch the spring is compressed, it exerts 500 lbf. A
non-linear spring rate is one for which the relation between the spring's compression and the force exerted cannot be fitted adequately to a linear model. For example, the first inch exerts 500 lbf force, the second inch exerts an additional 550 lbf (for a total of 1050 lbf), the third inch exerts another 600 lbf (for a total of 1650 lbf). In contrast a 500 lbf/in linear spring compressed to 3 inches will only exert 1500 lbf.
The spring rate of a coil spring may be calculated by a simple algebraic equation or it may be measured in a spring testing machine. The spring constant k can be calculated as follows:
where d is the wire diameter, G is the spring's shear modulus (e.g., about 12,000,000 lbf/in2 or 80 GPa for steel), and N is the number of wraps and D is the diameter of the coil.
Wheel rate
Wheel rate is the effective spring rate when measured at the wheel. This is as opposed to simply measuring the spring rate alone.
Wheel rate is usually equal to or considerably less than the spring rate. Commonly, springs are mounted on control arms, swing arms or some other pivoting suspension member. Consider the example above where the spring rate was calculated to be
500 lbs/inch, if you were to move the wheel 1 inch (without moving the car), the spring more than likely compresses a smaller amount. Lets assume the spring moved 0.75 inches, the lever arm ratio would be 0.75 to 1. The wheel rate is calculated by taking the square of the ratio (0.5625) times the spring rate. Squaring the ratio is because the ratio has two effects on the wheel rate. The ratio applies to both the force and distance traveled.
Wheel rate on independent suspension is fairly straight-forward. However, special consideration must be taken with some non-independent suspension designs. Take the case of the straight axle. When viewed from the front or rear, the wheel rate can be measured by the means above. Yet because the wheels are not independent, when viewed from the side under acceleration or braking the pivot point is at infinity (because both wheels have moved) and the spring is directly inline with the wheel contact patch. The result is often that the effective wheel rate under cornering is different from what it is under acceleration and braking. This variation in wheel rate may be minimized by locating the spring as close to the wheel as possible.
Roll couple percentage
Roll couple percentage is the effective wheel rates, in roll, of each axle of the vehicle just as a ratio of the vehicle's total roll rate. Roll Couple Percentage is critical in accurately balancing the handling of a vehicle. It is commonly adjusted through the use of anti-roll bars, but can also be changed through the use of different springs.
A vehicle with a roll couple percentage of 70% will transfer 70% of its sprung weight transfer at the front of the vehicle during cornering. This is also commonly known as "Total Lateral Load Transfer Distribution" or "TLLTD".
Weight transfer
Weight transfer during cornering, acceleration or braking is usually calculated per individual wheel and compared with the static weights for the same wheels.
The total amount of weight transfer is only affected by 4 factors: the distance between wheel centers (wheelbase in the case of braking, or track width in the case of cornering) the height of the center of gravity, the mass of the vehicle, and the amount of acceleration experienced.
The speed at which weight transfer occurs as well as through which components it transfers is complex and is determined by many factors including but not limited to roll center height, spring and damper rates, anti-roll bar stiffness and the kinematic design of the suspension links.
Unsprung weight transfer
Unsprung weight transfer is calculated based on the weight of the vehicle's components that are not supported by the springs. This includes tires, wheels, brakes, spindles, half the control arm's weight and other components. These components are then (for calculation purposes) assumed to be connected to a vehicle with zero sprung weight. They are then put through the same dynamic loads. The weight transfer for cornering in the front would be equal to the total unsprung front weight times the
G-Force times the front unsprung center of gravity height divided by the front track width. The same is true for the rear.
Suspension type
Dependent suspensions include:
?Satchell link
?Panhard rod
?Watt's linkage
?WOBLink
?Mumford linkage
?Live axle
?Twist beam
?Beam axle
?leaf springs used for location (transverse or longitudinal)
The variety of independent systems is greater and includes:
?Swing axle
?Sliding pillar
?MacPherson strut/Chapman strut
?Upper and lower A-arm (double wishbone)
?multi-link suspension
?semi-trailing arm suspension
?swinging arm
?leaf springs
Armoured fighting vehicle suspension
Military AFVs, including tanks, have specialized suspension requirements. They can weigh more than seventy tons and are required to move at high speed over very rough ground. Their suspension components must be protected from land mines and antitank weapons. Tracked AFVs can have as many as nine road wheels on each side. Many wheeled AFVs have six or eight wheels, to help them ride over rough and soft ground. The earliest tanks of the Great War had fixed suspensions—with no movement whatsoever. This unsatisfactory situation was improved with leaf spring suspensions adopted from agricultural machinery, but even these had very limited travel. Speeds increased due to more powerful engines, and the quality of ride had to be improved. In the 1930s, the Christie suspension was developed, which allowed the use of coil springs inside a vehicle's armoured hull, by redirecting the direction of travel using a bell crank. Horstmann suspension was a variation which used a combination of bell crank and exterior coil springs, in use from the 1930s to the 1990s.
By the Second World War the other common type was torsion-bar suspension, getting spring force from twisting bars inside the hull—this had less travel than the Christie type, but was significantly more compact, allowing the installation of larger turret rings and heavier main armament. The torsion-bar suspension, sometimes including shock absorbers, has been the dominant heavy armored vehicle suspension since the Second World War.
中文翻译
悬吊系统
(亦称悬挂系统或悬载系统)是描述一种由弹簧、减震筒和连杆所构成的车用系统，用于连接车辆与其车轮。悬吊系统扮演双重的角色－让车辆的操控和煞车合乎良好的动态安全与操驾乐趣，并保持车主的舒适性及隔绝适当的路面噪音、弹跳与震动。这些特性通常都是互相牵制的，因此悬吊的调整就必须找到两者兼顾的位置。悬吊系统同时也保护车辆本身、或车上的货物行李等，避免这些东西损坏或磨耗。一台车辆的前轮与后轮悬吊设计有可能会大不相同。
在古早的埃及，就已经出现过板式弹簧的踪迹。
古代的兵工学家使用板式弹簧，以弯曲的方式来加强他们的攻城武器，起初的效果还不错。后来在投石器上所使用的板式弹簧更为精密，而且可以使用好几年。弹簧不一定由金属制造，也可使用坚硬的树枝当作弹簧，就像制弓一样。
马车
在19世纪早期，大部分的英国四轮马车都有配备弹簧；木制弹簧用于轻型单马车辆来避税，而较大的马车弹簧则采用铁制。这些铁制的弹簧由低碳钢制成而且通常迭成多层成为板式弹簧。[1]
英国的铁制弹簧不适用于当时美国大陆上粗糙不平的路面，转弯过快甚至会导致马车解体。在 1820 年代，新罕布什尔州康科德市的Abbot Downing 公司开发出一种系统，藉此让驿马车的车体能够支撑在称作「thoroughbraces」的皮带上，这样车厢的动态可改善成摆荡的动作，而不是像弹簧悬吊那样剧烈的上下震动。（有时驿马车本身也被称作「thoroughbrace」。）
汽车
汽车在早期开发时，视为自身动力推进的马车。但是相对来讲，马车是设计用来低速行驶的，因此它们的悬吊并不适用于内燃机引擎所能产生的高速行驶。1903年，德国的Mors汽车公司首次将车辆安装了减震筒。1920年，Leyland汽车公司在悬吊系统中加入了扭杆装置。1922年，Lancia Lambda开创先例地使用独立前轮悬吊，在1932年以后的市售车辆上更为常见。[2]
重要属性
弹簧刚性
弹簧刚性（或称悬吊刚性）是悬吊伸缩时，用来设定车高或其定位的要素之一。车辆载重大的通常会搭配更硬的悬吊来抵销额外的重量负载，否则可能在途中（或弹跳时）压毁了车辆。较硬的弹簧通常也用于性能用途，因为这时候悬吊在弹跳时是经常性下压的，这时会导致可用的弹跳伸缩量变少，造成破坏性的下压力。
弹簧太硬或太软都会造成车辆失去悬吊性能。一般来说，比较经常性载重的车辆具备较重或较硬的弹簧，其弹簧刚性接近车重的上限值。这样让车辆可以在控制性受载重惯性的限制下，正常地载货并操驾行驶。驾驶一台空的载货用卡车可能会对乘客感到较不舒适，是因为与车重相关的高弹簧刚性。赛车可以说是具备较硬的弹簧，而且会呈现不舒适的颠簸。然而，虽然我们说它们两者均具备硬弹簧，
但实际上一台2000磅的赛车与一台10000磅的卡车，其两者的弹簧刚性则是全然不同的。高级房车、的士或客运巴士通常可以说是具备较软的弹簧。车辆的弹簧若是老化或损坏，行驶时容易贴近地面，悬吊的总压缩量会降低，车体也容易侧倾。性能跑车的弹簧刚性有时不只是为了车重或载重的需求。
弹簧刚性的数学应用
弹簧刚性是一个比值，用来测量一个弹簧在偏斜时被压缩或伸展时的阻抗。按照虎克定律，弹力强度随着偏斜增加而增加。简单来讲，这个现象可以由下列公式所述：
其中
F为弹簧的施力
k为弹簧的刚性
x为静力平衡时的位移量，其长度为弹簧压缩或延展时。
由于本身车重、车辆载重、悬吊系统的空间限制或性能需求等因素下，弹簧刚性会受限在一段狭小的分布区段。
弹簧刚性的单位通常由N/mm表示（或lbf/in）。例如一个线性的弹簧刚性表示为 500 lbf/in，其代表弹簧每压缩一英吋，它可以施压 500 磅力。而一个具有非线性的弹簧刚性，代表它的压缩力与施力的关系无法适当地对应于一个线性模型。例如，第一英吋会施压 500 磅力，第二英吋会施压额外的 550 磅力（因此总共是 1050 磅力），第三英吋则会施压另外 600 磅力（总共达 1650 磅力）。相较之下，一个 500 lbf/in 的线性弹簧压缩了三英吋之后的施压力则只有
1500 磅力。
线圈弹簧的弹簧刚性可由简单的代数方程来计算求得，或是由弹簧测试机来测量。弹簧常数k可由下列公式计算：
其中d为线材直径，E为弹簧的弹性系数（例如钢铁的系数大约为 30,000,000 lbf/in2或是 207 GPa），N为线圈的缠绕次数，而D为线圈直径。
悬架刚性
悬架刚性为针对车辆轮架所测量出有效的弹簧刚性，但不只是单独对弹簧刚性做测量而已。
悬架刚性通常等于或小于弹簧刚性。一般来说，弹簧会固定在控制臂、摇臂或某些其他种类的枢轴支承机构上。假设前述例子中的弹簧刚性计算出为每吋 500 磅力，如果你将车轮垂直移动一英吋（车辆是静止的），则弹簧可能仅压缩了一小部份的量。假设弹簧只移动了 0.75 英吋，杠杆臂比率可能为 0.75 到 1 ，则悬架刚性可由弹簧刚性比值的平方倍（0.5625）而求得。将比值做平方倍的目的在于它对于悬架刚性有两个作用存在，这个比值同时影响了施力大小与位移量。
[3]
独立悬吊系统下的悬架刚性就非常简单明了，但对于某些非独立悬吊系统的设计就必须考虑到一些特殊状况。以车轴的纵向角度来看，若由前方或后方来看，悬架刚性可以由前述的方式去测量得出。然而由于轮架并非独立的，在加速或减速时侧向来看，支点会位在无限远的位置（因为前后轮都移动了）。过弯与加减速
时的有效悬架刚性也往往有不一样的结果，将弹簧的定位尽可能地靠近车轮可以将悬架刚性的差异降到最小。
侧倾力耦百分比
在车辆摇晃时，侧倾力耦百分比为车身各轴在线发生的有效悬架刚性数值，为车辆总侧倾率的某个比值。侧倾力耦百分比在精确平衡车辆的操控上是非常关键的因素。
一台侧倾力耦百分比 70% 的车辆，在过弯时会将本身 70% 的悬吊载重转移到车辆前方。
重量转移
重量转移通常针对单一车轮在过弯、加速或煞车等状况下，相较于该轮净重时的情形。过弯的轮载重必须先得知静止时的轮载重，并依照每个轮架的簧上载重、簧下总重，或是顶举力的大小来增减。有些赛车业界会使用一些假名词，或是将顶举力和悬吊载重转移等因素统一用一个词组名词来称呼，例如「side bite」。通常会这样做的理由在于，他们可能没必要知道这么详细，或是刻意混淆对手而不让对方得知车辆的性能，因此使用一般人容易接受的「拟人」词汇。
非承载重量转移
非承载重量转移是由非悬吊支撑的车辆组件重量所计算求得，这些组件包含了轮胎、轮圈、煞车、轮轴、控制臂一半的重量，以及其他的组件。这些连接于车身的组件会假设成无重量（便于计算用途），然后放在同样的动态负载。过弯时，前轮的重量转移会等于：前轮非承载总重×重力×前轮非承载重心高度÷前轮车轴宽度。此算法同样适用于后轮。
悬吊系统类型
独立悬吊系统(亦称独立悬挂系统)包含了以下几种悬挂系统：Swing axle 摇轴式、 Sliding pillar 滑动支柱式、 MacPherson strut/Chapman strut 麦佛逊(麦花臣)支柱悬挂/查普曼支柱式悬吊(麦佛逊支柱悬吊系统由美国福特公司发明，避震性良好占空间小，查普曼支柱式悬吊由英国莲花汽车创办人查普曼改良麦佛逊支柱所发明，多用在后悬吊系统)、 Upper and lower A-arm 双A臂式(或称double wishbone、双A型控制臂、不等长控制臂，基本设计已兼具车辆行驶时的纵向与横向控制，跑车常用) 、 multi-link suspension 多连杆式、
semi-trailing arm suspension 半拖曳臂式、 swinging arm 摇臂式、leaf springs 叶片弹簧式。
非独立式悬吊系统包含Satchell link、 Panhard rod、 Watt's linkage(澳洲福特汽车所发明，可改善活轴或固定轴悬吊的操控性)、 WOBLink、 Mumford linkage、 Live axle(活轴悬吊，有传动功能的Beam axle)、 Twist beam(亦称Torsion beam axle扭力梁式悬吊，搭配拖曳臂，可算半独立式悬吊系统，中小型车后悬吊常使用)、 Beam axle(无传动功能称Solid axle，有传动功能称Live axle，通称Beam axle)、 leaf springs used for location (transverse or longitudinal) 。
装甲战车悬吊系统
早期战车底盘为固定悬吊，震动大机动性差，后来采用农耕机叶片弹簧悬吊，但改善有限。二十世纪30年代美国人John Walter Christie 发明坦克用全轮独立悬挂系统，但与美国军方因规格问题未达成协议，共产苏联发现美军未采用此技术后，迅速买去这技术专利，让苏联发展出行驶恶劣路面如履平地的优秀T34坦克，越野机动能力远胜纳粹坦克，成为击败纳粹主力军队改写历史的发明。英
国另有一种Horstmann坦克悬吊是Christie悬吊系统的变异版。另一种二战时至今的坦克悬吊系统为扭力棒(Torsion-bar)悬吊，避震行程不如Christie悬吊，但占空间比Christie悬吊系统小，可容纳大车轮与重装甲，也可装避震器(减震筒)，今日重装甲坦克常用。
外文出处： 《Exploiting Software How to Break Code》By Greg Hoglund, Gary McGraw Publisher : Addison Wesley Pub Date : February 17, 2004 ISBN : 0-201-78695-8 译文标题： JDBC接口技术 译文： JDBC是一种可用于执行SQL语句的JavaAPI（ApplicationProgrammingInterface应用程序设计接口）。它由一些Java语言编写的类和界面组成。JDBC为数据库应用开发人员、数据库前台工具开发人员提供了一种标准的应用程序设计接口，使开发人员可以用纯Java语言编写完整的数据库应用程序。 一、ODBC到JDBC的发展历程 说到JDBC，很容易让人联想到另一个十分熟悉的字眼“ODBC”。它们之间有没有联系呢？如果有，那么它们之间又是怎样的关系呢？ ODBC是OpenDatabaseConnectivity的英文简写。它是一种用来在相关或不相关的数据库管理系统（DBMS）中存取数据的，用C语言实现的，标准应用程序数据接口。通过ODBCAPI，应用程序可以存取保存在多种不同数据库管理系统（DBMS）中的数据，而不论每个DBMS使用了何种数据存储格式和编程接口。 1．ODBC的结构模型 ODBC的结构包括四个主要部分：应用程序接口、驱动器管理器、数据库驱动器和数据源。应用程序接口：屏蔽不同的ODBC数据库驱动器之间函数调用的差别，为用户提供统一的SQL编程接口。 驱动器管理器：为应用程序装载数据库驱动器。 数据库驱动器：实现ODBC的函数调用，提供对特定数据源的SQL请求。如果需要，数据库驱动器将修改应用程序的请求，使得请求符合相关的DBMS所支持的文法。 数据源：由用户想要存取的数据以及与它相关的操作系统、DBMS和用于访问DBMS的网络平台组成。 虽然ODBC驱动器管理器的主要目的是加载数据库驱动器，以便ODBC函数调用，但是数据库驱动器本身也执行ODBC函数调用，并与数据库相互配合。因此当应用系统发出调用与数据源进行连接时，数据库驱动器能管理通信协议。当建立起与数据源的连接时，数据库驱动器便能处理应用系统向DBMS发出的请求，对分析或发自数据源的设计进行必要的翻译，并将结果返回给应用系统。 2．JDBC的诞生 自从Java语言于1995年5月正式公布以来，Java风靡全球。出现大量的用java语言编写的程序，其中也包括数据库应用程序。由于没有一个Java语言的API，编程人员不得不在Java程序中加入C语言的ODBC函数调用。这就使很多Java的优秀特性无法充分发挥，比如平台无关性、面向对象特性等。随着越来越多的编程人员对Java语言的日益喜爱，越来越多的公司在Java程序开发上投入的精力日益增加，对java语言接口的访问数据库的API 的要求越来越强烈。也由于ODBC的有其不足之处，比如它并不容易使用，没有面向对象的特性等等，SUN公司决定开发一Java语言为接口的数据库应用程序开发接口。在JDK1．x 版本中，JDBC只是一个可选部件，到了JDK1．1公布时，SQL类包（也就是JDBCAPI）
On the vehicle sideslip angle estimation through neural networks: Numerical and experimental results. S. Melzi,E. Sabbioni Mechanical Systems and Signal Processing 25 (2011)：14~28 电脑估计车辆侧滑角的数值和实验结果 S.梅尔兹,E.赛博毕宁 机械系统和信号处理2011年第25期：14~28
摘要 将稳定控制系统应用于差动制动内/外轮胎是现在对客车车辆的标准（电子稳定系统ESP、直接偏航力矩控制DYC）。这些系统假设将两个偏航率(通常是衡量板)和侧滑角作为控制变量。不幸的是后者的具体数值只有通过非常昂贵却不适合用于普通车辆的设备才可以实现直接被测量,因此只能估计其数值。几个州的观察家最终将适应参数的参考车辆模型作为开发的目的。然而侧滑角的估计还是一个悬而未决的问题。为了避免有关参考模型参数识别/适应的问题,本文提出了分层神经网络方法估算侧滑角。横向加速度、偏航角速率、速度和引导角,都可以作为普通传感器的输入值。人脑中的神经网络的设计和定义的策略构成训练集通过数值模拟与七分布式光纤传感器的车辆模型都已经获得了。在各种路面上神经网络性能和稳定已经通过处理实验数据获得和相应的车辆和提到几个处理演习(一步引导、电源、双车道变化等)得以证实。结果通常显示估计和测量的侧滑角之间有良好的一致性。 1 介绍 稳定控制系统可以防止车辆的旋转和漂移。实际上，在轮胎和道路之间的物理极限的附着力下驾驶汽车是一个极其困难的任务。通常大部分司机不能处理这种情况和失去控制的车辆。最近,为了提高车辆安全，稳定控制系统(ESP[1,2]; DYC[3,4])介绍了通过将差动制动/驱动扭矩应用到内/外轮胎来试图控制偏航力矩的方法。 横摆力矩控制系统（DYC）是基于偏航角速率反馈进行控制的。在这种情况下,控制系统使车辆处于由司机转向输入和车辆速度控制的期望的偏航率[3,4]。然而为了确保稳定，防止特别是在低摩擦路面上的车辆侧滑角变得太大是必要的[1,2]。事实上由于非线性回旋力和轮胎滑移角之间的关系，转向角的变化几乎不改变偏航力矩。因此两个偏航率和侧滑角的实现需要一个有效的稳定控制系统[1,2]。不幸的是,能直接测量的侧滑角只能用特殊设备(光学传感器或GPS惯性传感器的组合)，现在这种设备非常昂贵,不适合在普通汽车上实现。因此, 必须在实时测量的基础上进行侧滑角估计，具体是测量横向/纵向加速度、角速度、引导角度和车轮角速度来估计车辆速度。 在主要是基于状态观测器/卡尔曼滤波器(5、6)的文学资料里, 提出了几个侧滑角估计策略。因为国家观察员都基于一个参考车辆模型,他们只有准确已知模型参数的情况下，才可以提供一个令人满意的估计。根据这种观点,轮胎特性尤其关键取决于附着条件、温度、磨损等特点。 轮胎转弯刚度的提出就是为了克服这些困难,适应观察员能够提供一个同步估计的侧滑角和附着条件[7,8]。这种方法的弊端是一个更复杂的布局的估计量导致需要很高的计算工作量。 另一种方法可由代表神经网络由于其承受能力模型非线性系统，这样不需要一个参
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
本科生毕业论文（设计）题目文献综述文献综述随着改革开放的深入，交通运输在生活中的作用越来越明显，高速公路的建设成为了国民建设中的一个重大问题。由于高速公路具有汽车专用，分隔行驶，全部立交，控制出入以及高标准，高要求，设备功能完善等功能，与一般公路相比具有很多优点，所以具有很强的实用性。目前，我国高等级公路建设正处在“质”与“量”并重的重要发展阶段。从大陆第一条高速公路——沪嘉高速开始，中国大陆高速公路建设进入了一个崭新的时期。高速公路在二十多年间展现出了巨大的优越性，在以建成的高速公路沿线及腹地迅速兴起了工业企业建设的热【1】潮，地价增值，地方税收增加，投资环境发生巨大变化。目前我国的高速公路主要分布在东南沿海，我国的沿海地带，大部分是淤泥质海岸。因此，沿海特别是大江大河河口附近多为河相、海相或泻湖相沉积层，在地质上属于第四纪全新纪Q4 土层，多属于【2】东南海岸土的类别多为淤泥，淤泥质亚黏饱和的正常压密黏土。土。这类地基的主要特点是：具有高含水量、大孔隙、低密度、低强度、高压缩性、低透水性、中等灵敏度等特点；具有一定的结构性。由于这类地基存在这些特点，在软粘土地基上建造建筑物普遍存在稳定及变形的问题。以高速为例，由于高速的路堤高度不大，所以稳定问题并不突出，但是变形问题很明显。目前高速桥头跳车以及高填方段、填挖结合部等位置因地基差异沉降对路面结构造成的不良影响已引起公路建设、设计、监理、施工等部门的日益重视。如何解决高等级公路桥头跳车问题已成为刻不容缓的大事。造成桥头跳车的原因【3】有很多：1、土质不良引起的地基沉陷：土质不良，由此产生沉陷是桥头跳车的主要原因。桥涵通常位于沟壑地方，地下水位较高，此类土天然含水量大于液限，天然孔隙比大，常含有机质，压缩性高，抗剪强度低，一旦受到扰动，天然结构易受破坏，强度便显著降低，桥头路基填筑高度较大，产生基底应力相对较大，在车辆荷载作用下，更容易引起地基沉陷，且变形稳定历时往往持续数年乃至更长的时间。既便是在一些稳定地基，在外荷作用下，也无可避免出现这个问题。2、台后填料的压缩沉降：台后填料一
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
Automobile Brake System The braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes. Two complete independent braking systems are used on the car. They are the service brake and the parking brake. The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set. The brake system is composed of the following basic c omponents: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and “pads” are pushed by cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car. The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).
I / 11 本科毕业设计外文翻译 <2018届） 论文题目基于WEB 的J2EE 的信息系统的方法研究 作者姓名[单击此处输入姓名] 指导教师[单击此处输入姓名] 学科(专业 > 所在学院计算机科学与技术学院 提交日期[时间 ]
基于WEB的J2EE的信息系统的方法研究 摘要：本文介绍基于工程的Java开发框架背后的概念，并介绍它如何用于IT 工程开发。因为有许多相同设计和开发工作在不同的方式下重复，而且并不总是符合最佳实践，所以许多开发框架建立了。我们已经定义了共同关注的问题和应用模式，代表有效解决办法的工具。开发框架提供：<1）从用户界面到数据集成的应用程序开发堆栈；<2）一个架构，基本环境及他们的相关技术，这些技术用来使用其他一些框架。架构定义了一个开发方法，其目的是协助客户开发工程。 关键词：J2EE 框架WEB开发 一、引言 软件工具包用来进行复杂的空间动态系统的非线性分析越来越多地使用基于Web的网络平台，以实现他们的用户界面，科学分析，分布仿真结果和科学家之间的信息交流。对于许多应用系统基于Web访问的非线性分析模拟软件成为一个重要组成部分。网络硬件和软件方面的密集技术变革[1]提供了比过去更多的自由选择机会[2]。因此，WEB平台的合理选择和发展对整个地区的非线性分析及其众多的应用程序具有越来越重要的意义。现阶段的WEB发展的特点是出现了大量的开源框架。框架将Web开发提到一个更高的水平，使基本功能的重复使用成为可能和从而提高了开发的生产力。 在某些情况下，开源框架没有提供常见问题的一个解决方案。出于这个原因，开发在开源框架的基础上建立自己的工程发展框架。本文旨在描述是一个基于Java的框架，该框架利用了开源框架并有助于开发基于Web的应用。通过分析现有的开源框架，本文提出了新的架构，基本环境及他们用来提高和利用其他一些框架的相关技术。架构定义了自己开发方法，其目的是协助客户开发和事例工程。 应用程序设计应该关注在工程中的重复利用。即使有独特的功能要求，也
毕业设计（论文） 外文翻译 题目西安市水源工程中的 水电站设计 专业水利水电工程 班级 学生 指导教师 2016年
研究钢弧形闸门的动态稳定性 牛志国 河海大学水利水电工程学院，中国南京，邮编210098 nzg_197901@https://www.doczj.com/doc/f416400768.html,，niuzhiguo@https://www.doczj.com/doc/f416400768.html, 李同春 河海大学水利水电工程学院，中国南京，邮编210098 ltchhu@https://www.doczj.com/doc/f416400768.html, 摘要 由于钢弧形闸门的结构特征和弹力，调查对参数共振的弧形闸门的臂一直是研究领域的热点话题弧形弧形闸门的动力稳定性。在这个论文中，简化空间框架作为分析模型，根据弹性体薄壁结构的扰动方程和梁单元模型和薄壁结构的梁单元模型，动态不稳定区域的弧形闸门可以通过有限元的方法，应用有限元的方法计算动态不稳定性的主要区域的弧形弧形闸门工作。此外，结合物理和数值模型，对识别新方法的参数共振钢弧形闸门提出了调查，本文不仅是重要的改进弧形闸门的参数振动的计算方法，但也为进一步研究弧形弧形闸门结构的动态稳定性打下了坚实的基础。 简介 低举升力，没有门槽，好流型，和操作方便等优点，使钢弧形闸门已经广泛应用于水工建筑物。弧形闸门的结构特点是液压完全作用于弧形闸门，通过门叶和主大梁，所以弧形闸门臂是主要的组件确保弧形闸门安全操作。如果周期性轴向载荷作用于手臂，手臂的不稳定是在一定条件下可能发生。调查指出:在弧形闸门的20次事故中，除了极特殊的破坏情况下，弧形闸门的破坏的原因是弧形闸门臂的不稳定;此外，明显的动态作用下发生破坏。例如:张山闸，位于中国的江苏省，包括36个弧形闸门。当一个弧形闸门打开放水时，门被破坏了，而其他弧形闸门则关闭，受到静态静水压力仍然是一样的，很明显，一个动态的加载是造成的弧形闸门破坏一个主要因素。因此弧形闸门臂的动态不稳定是造成弧形闸门(特别是低水头的弧形闸门)破坏的主要原是毫无疑问。
Automobile Brake System汽车制动系统 The braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes. Two complete independent braking systems are used on the car. They are the service brake and the parking brake. The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set. The brake system is composed of the following basic components: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the c ar. The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure). Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.
Section 3 Design philosophy, design method and earth pressures 3.1 Design philosophy 3.1.1 General The design of earth retaining structures requires consideration of the interaction between the ground and the structure. It requires the performance of two sets of calculations: 1）a set of equilibrium calculations to determine the overall proportions and the geometry of the structure necessary to achieve equilibrium under the relevant earth pressures and forces; 2）structural design calculations to determine the size and properties of thestructural sections necessary to resist the bending moments and shear forces determined from the equilibrium calculations. Both sets of calculations are carried out for specific design situations (see 3.2.2) in accordance with the principles of limit state design. The selected design situations should be sufficiently Severe and varied so as to encompass all reasonable conditions which can be foreseen during the period of construction and the life of the retaining wall. 3.1.2 Limit state design This code of practice adopts the philosophy of limit state design. This philosophy does not impose upon the designer any special requirements as to the manner in which the safety and stability of the retaining wall may be achieved, whether by overall factors of safety, or partial factors of safety, or by other measures. Limit states (see 1.3.13) are classified into: a) ultimate limit states (see 3.1.3); b) serviceability limit states (see 3.1.4). Typical ultimate limit states are depicted in figure 3. Rupture states which are reached before collapse occurs are, for simplicity, also classified and
毕业设计（论文） 外文文献翻译 题目：A new constructing auxiliary function method for global optimization 学院： 专业名称： 学号： 学生姓名： 指导教师： 2014年2月14日
一个新的辅助函数的构造方法的全局优化 Jiang-She Zhang，Yong-Jun Wang https://www.doczj.com/doc/f416400768.html,/10.1016/j.mcm.2007.08.007 非线性函数优化问题中具有许多局部极小，在他们的搜索空间中的应用，如工程设计，分子生物学是广泛的，和神经网络训练．虽然现有的传统的方法，如最速下降方法，牛顿法，拟牛顿方法，信赖域方法，共轭梯度法，收敛迅速，可以找到解决方案，为高精度的连续可微函数，这在很大程度上依赖于初始点和最终的全局解的质量很难保证．在全局优化中存在的困难阻碍了许多学科的进一步发展．因此，全局优化通常成为一个具有挑战性的计算任务的研究． 一般来说，设计一个全局优化算法是由两个原因造成的困难：一是如何确定所得到的最小是全球性的（当时全球最小的是事先不知道），和其他的是，如何从中获得一个更好的最小跳．对第一个问题，一个停止规则称为贝叶斯终止条件已被报道．许多最近提出的算法的目标是在处理第二个问题．一般来说，这些方法可以被类?主要分两大类，即：（一）确定的方法，及（ii）的随机方法．随机的方法是基于生物或统计物理学，它跳到当地的最低使用基于概率的方法．这些方法包括遗传算法（GA），模拟退火法（SA）和粒子群优化算法（PSO）．虽然这些方法有其用途，它们往往收敛速度慢和寻找更高精度的解决方案是耗费时间．他们更容易实现和解决组合优化问题．然而，确定性方法如填充函数法，盾构法，等，收敛迅速，具有较高的精度，通常可以找到一个解决方案．这些方法往往依赖于修改目标函数的函数“少”或“低”局部极小，比原来的目标函数，并设计算法来减少该?ED功能逃离局部极小更好的发现． 引用确定性算法中，扩散方程法，有效能量的方法，和积分变换方法近似的原始目标函数的粗结构由一组平滑函数的极小的“少”．这些方法通过修改目标函数的原始目标函数的积分．这样的集成是实现太贵，和辅助功能的最终解决必须追溯到
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
CLUTCH The engine produces the power to drive the vehicle. The drive line or drive train transfers the power of the engine to the wheels. The drive train consists of the parts from the back of the flywh eel to the wheels. These parts include the clutch, th e transmission, the drive shaft, and the final drive assembly (Figure 8-1). The clutch which includes the flywheel, clutch disc, pressure plate, springs, pressure plate cover and the linkage necessary to operate the clutch is a rotating mechanism between t he engine and the transmission (Figure 8-2). It operates through friction which comes from contact between the parts. That is the reason why the clutch is called a friction mechanism. After engagement, the clutch must continue to transmit all the engine torque to the transmission depending on the friction without slippage. The clutch is also used to disengage the engine from the drive train whenever the gears in the transmission are being shifted from one gear ratio to another. To start the engine or shift the gears, the driver has to depress the clutch pedal with the purpose of disengagement the transmission from the engine. At that time, the driven members connected to the transmission input shaft are either stationary or rotating at a speed that is slower or faster than the driving members connected to the engine crankshaft. There is no spring pressure on the clutch assembly parts. So there is no friction between the driving members and driven members. As the driver lets loose the clutch pedal, spring pre ssure increases on the clutch parts. Friction between the parts also increases. The pressure exerted by the springs on the driven members is controlled by the driver through the clutch pedal and linkage. The positive engagement of the driving and driven members is made possible by the friction between the surfaces of the members. When full spring pressure is applied, the speed of the driving and driven members should be the same. At the