关键词:动态断裂、陶瓷、随机性质,数值模拟;Micro-cracking机制;Mesh-dependency。 Rate-hardening
Keywords(关键词): Dynamic fracture(动态断裂); Ceramics(陶瓷); Stochastic property(随机性能); Numerical simulation(数字模拟); Micro-cracking mechanism(微观裂纹机制); Mesh-dependency(依赖于网格的某种方法);Rate-hardening(硬化速度)
毕业论文是Graduation thesis 若要在论文里指论文就可以直接说thesis或者paper
Thesis For Graduation毕业论文Thesis For Academic Degree学位论文Thesis表示比较严肃的文章,是带有一定目的的,研究性的文章。学位论文,研究报告。
正在做这个项目,不过没有英文。
Thesis For Graduation毕业论文Thesis For Academic Degree学位论文Thesis表示比较严肃的文章,是带有一定目的的,研究性的文章。学位论文,研究报告。
Car partsEngine The engine is a power plant, which provides power to drive the automobile. In most automobile engines,the explosive power of the mixture of air and gasoline drives the pistons.The pistons turn a crankshaft to which they are attached The rotating force of the crankshaft makes the automobile’s wheels turn.Some automobiles are powered by another kind of engine,known as the rotary valve,rotating combustion engine or Wankel engine The rotary valve engine also draws in a mixture of air and fuel, which is then compressed and burnt.A motor revolving in an elliptical chamber is connected to a shaft,Which finally drives the rear wheels.In most automobiles.the engine is mounted at the front end of the car,with the clutch and gearbox immediately behind it;the engine, clutch and gearbox are assembled into a single unit A number of systems are necessary to make an engine work . A lubrication system is neededto reduce friction and prevent engine wear. A cooling system is required to keep the engine’s temperature within safe limits .The engine must be provided with the correct amount of air and fuel by a fuel system. The mixture of air and fuel must be ignited inside the cylinder at just the right time by an ignition system.Finally, an electrical system is required to operate the cranking motor that starts the engine and to provide electrical energy to power engine accessoriesLubrication System An engine has many moving parts which eventually develop wear,as they move against each other.The engine circulates oil between these moving parts to prevent the metal-to-metal contact that results in wear. Parts that are oiled can move more easily with less friction and hence power loss due to friction is minimized.The secondary function of lubricant is to act as a coolant and also as a sealing medium to prevent leakages.Finally,a film of lubricant on the cylinder walls helps the tings in sealing and thus improves the engine’s compressions.Cooling System Due to the combustion of fuel with air inside the cylinder,the temperature of the engine parts increases.This increase of temperature directly affects the engine performance and the life of the engine parts.The cooling system keeps the engine operating at the efficient temperature.Whatever the driving conditions, the system is designed to prevent both overheating and overcooling.Fuel System The main function of the fuel supply system is to provide fuel to the carburetor or injection system at a rate and pressure sufficient to meet engine demands under all conditions of load,speed and gradients encountered by the vehicle.The fuel system must also have enough reserve fuel for several miles of vehicle operation.Ignition System The purpose of the ignition system is to provide assistance for the combustion of fuel either by a high voltage spark or self-ignition in each of the engine’s cylinder at the right time so that the air-fuel mixture can burn completely. The fuel supplied to the combustion chamber must be ignited to deliver power.In a spark—ignition engine an electric spark is used for this purpose.The compression—ignition engine does not require a separate ignition system because the ignition is affected by compression of the mixture to a high pressure. Electrical System The engine’s electrical system provides energy to operate a starting motor and to power all the accessories.The main components of the electrical system are a battery,an alternator, a starting motor, ignition coil and heater.Frame The frame provides a foundation for the engine and the body of the vehicle . The flame is constructed from square or box-shaped steel members strong enough to support the weight of the body and other components. The automobile frame is usually made up of a number of members welded or riveted together to give the final shape.The engine is mounted on the frame with rubber pads which absorb vibrations and also provide damping of these vibrations.Absorption and damping of vibrations protects passengers from discomfort caused by shocks. The frame is supported on wheel axles by means of springs.This whole assembly is calledthe chassis. Suspension System The function of the suspension system is to absorb vibrations due to the up and down motion of wheels.caused by the irregularities in the road surface . The springs, connecting linkages.and shock absorber comprise the suspension system of a vehicle.The suspension system is of two types: (1)Rigid system(2)Independent systemIn the rigid system, the road springs are attached to a rigid beam axle. It is mostly used in the front axle of commercial vehicles and in the car axle of all types of independent system does not have a rigid axle. Each wheel is free to move vertically without any reaction on its mating wheel. The independent system is mostly used in small cars Power TrainThe power train carries the power that the engine produces to the car wheels. It consists of the clutch (on cars with a manual transmission), transmission (a system of gears that increases the turning effort of the engine to move the automobile ),drive shaft, differential and rear clutch is required with the manual transmission system to temporarily disconnect the engine from wheels. Such disengagement of the power train from the engine is essential while changing the gear ratio or while stopping the main function of the transmission is to provide the necessary variation to the torque applied by the engine to the wheels. This is achieved by changing the gearing ratio between the engine output shaft and the drive ShaftThe drive shaft or propeller connects the gearbox and the differential unit. The drive shaft has universal joints at its ends.DifferentialThe function of the differential is to split the power received from the propeller shaft to the rear axle shaft. It allows the rear wheels to be driven at different speeds when the vehicle takes a bend or falls into a ditch. AxlesAxles are the shafts on which road wheels are mounted. The road wheels are provided with the required drive through these axles.WheelThe automobile wheels take the load of the vehicle and also produce tractive force to move the vehicle. The wheels are also used for retardation and for stopping the SystemThe steering system is used for changing the direction of the vehicle .The major requirements in any steering mechanism are that it should be precise and easy to handle, and that the front wheels should have a tendency to return to the straight-ahead position after a turn. A gear mechanism, which is known as steering gear, is used in this system to increase the steering effort provided by the driver. This system makes the vehicle steering very easy as the driver does not have to put in much effort.Vehicle steering is not only required on a curved road but also while maneuvering on the busy traffic roads.The steering system allows the vehicle to be guided i.e.to be turned left or right. Braking SystemBrakes are required for slowing down or stopping a moving vehicle.The braking system may be operated mechanically or hydraulically. 95 percent of the braking systems in use today are of the hydraulic brake consist of two members.one rotating and the other stationary.There are various means by which the two member call be brought in contact,thus reducing the speed of the major components of the braking system are:brake pedal, master cylinder, wheel Cylinder, brake pipe,brake shoes.brake packing plant and linkages.As the load on the vehicle and the vehicle speed has increased according to recent trends.in modem days, the importance of the braking system has also increased and power brakes are now being preferred.Power brakes utilize vacuum and air pressure to provide most of the brake————applying effort.汽车部件发动机发动机是一种动力机械设备.它为汽车提供动力。在大部分汽车发动机中.空气和汽油的混合气体产生的爆炸性能量驱动活动活塞运动。活塞使它们所连接的曲轴转动。曲轴的转动力量使汽车的车轮转动。一些汽车是由另外一种发动机提供动力的,这种发动机被认为是旋转气门、旋转燃烧或汪克尔发动机。转子发动机也是吸入空气和燃料的混合气,混合气被压缩和燃烧•在一个椭圆形的室内旋转的发动机连接着一个轴,这个轴将最终驱动后面的车轮。大部分汽车中,发动机是架在汽车的前面末端的,离台器和变速箱在它后面,发动帆、离台器和变速箱被装配成一个整体。发动机工作时有很多系统都是必要的。润滑系统可以减少摩擦并减轻发动机磨损。冷却系统被用来保持发动机的温度在安全范围内。发动机必须有燃油系统保证适当数量的空气和燃料供给。空气和燃油混合物必须由点火系统在适当的时间在气缸内被点燃。最后,电子系统被用来控制启动发动机用的电动机和为发动机附件提供电能。润滑系统发动机有许多最终会被磨损的运动部件,因为它们是相对运动的。发动机使润滑油在这些运动的部件间循环,以避免因金属与金属之间的接触而导致磨损。被润滑过的部件能够因为摩擦减少而容易运动,因摩擦导致的能量损失是最小的。润滑油的第二个功能是作为冷却液和防止泄露。最后,气缸壁上的润滑油薄膜有助于活塞环密封并因此提高发动机的压缩性。冷却系统 由于燃料与空气在气缸内燃烧,从而使发动机部件温度升高。温度升高直接影响发动机的性能和发动机部件的寿命。冷却系统使发动机工作保持在有效的温度。不管驾驶条件如何,发动机系统被设计成既能防止过热又能防止过冷。燃料供给系统燃料供给系统的主要功能是以一定的比例和压力给化油器或喷射系统提供燃料,并在汽车遇到的所有情况下,满足发动机对负载、速度和坡度的需要。燃料系统也必须为汽车行驶几英里保留足够的燃料。点火系统点火系统的作用是在适当的时间使燃料燃烧,不管是高压电火花还是在每个发动机气缸中的自燃,以便于气体混合物的完全燃烧。提供给燃料室的燃料必须被点燃以提供能量。在一个火花点火发动机中,电火花就是用于这个目的。压缩点火发动机不需要一个独立的点火系统,因为点火会受混合气压缩压力的影响。电气系统发动机的电气系统提供能量给起动电动机并给所有附件提供电能。电气系统的主要构件是蓄电池、交流发电机、起动电动机、点火线圈和加热器。车架车架为汽车发动机和车身提供了一个安装框架。车架用方刚或盒形钢铁制造,有足够的强度支撑车身和其他构件的重量。汽车车架通常由一些焊接或铆接在一起的零件构成,从而形成最后的形状。发动机和橡胶垫被圈定在车架上。橡胶垫可以吸收振动,也可以提供这些振动的阻尼减轻乘客由于振动产生的不适。悬架系统悬架系统的功能是吸收由于路面不平使车轮上下运动所产生的振动。弹性元件、连接装置和减振器组成了汽车的悬架系统。悬架系统有两种类型:(1)刚性悬架系统(2)独立悬架系统在刚性悬架系统中,弹簧被系在刚性横梁上,这种系统主要被用在商用车辆的前轴和所有类型车辆的车轴上。独立悬架系统没有一根坚硬的轴。每个车架可以自由做垂直运动而相对应的另一侧车轮没有任何反应。独立悬架系统主要用在小汽车上。传动系统传动系把发动机产生的能量传递给车轮。它包括离台器(汽车上用手动变速器)、传动系(一系列的齿轮,把由发动机产生的转矩增强.推动汽车)、驱动轴、差速器和后挢。离合器离合器用于手动变速的传动系统。用它暂时把发动机和车轮之间的动力传递分开。当换档或停车时,把传动系和发动机的连接断开是很必要的。变速籍变速箱的主要功能是通过发动机把各种必需的扭矩提供给车轮,这是通过改变发动机输出轴和驱动轴两者之阃的传动比来实现的。驱动轴驱动轴或叫推动轴与齿轮箱和差动器相连。驱动轴通常在末端具有万向节。差速器差速器的功能是把来自传动轴的能量分给后轿。当汽车转弯或掉沟时,它允许后轮以不同的逮度驱动。车轿车桥是指用来安装车轮的轴,通过这些车桥向车轮提供必需的驱动力。 车轮车轮支承着整辆车.并产生牵引力来驱动汽车。车轮也用于减速和停车。转向系统转向系统是用来改变汽车方向的,在任何转向机构中最主要的就是转向精确且容易控制,同时前轮在转向后又能自动回正。一个齿轮机构,通常认为是转向齿轮,在这个系统内用来增强由驾驶员提供的转向力,这个系统使得汽车转向非常容易,驾驶员不用费报大的力。不仅仅是在弯曲的公路上需要汽车转向,在交通拥挤的路上也需要巧妙地控制。转向系统使得汽车可以被控制向左或者向右转向。制动系统制动用来使车辆放慢速度或者停车。制动系统可以是机械制动或者液压制动。现在用的制动系统95%都是液压型的。所有的制动系统都包含两种元件,一种是旋转零件,另一种是固定零件,有各种各样方法使得这两个元件相接触而使车辆减速。制动系统的主要组成部分:制动踏扳、主制动缸、车轮制动、制动鼓、制动管路、制动蹄、制动装备和联动装置。随着汽车负载和车速的增大,目前制动系统的重要性也在增大,并且现在人们更喜欢助力制动。助力制动利用真空和空气压力来提供更好的制动力。
Car partsEngine The engine is a power plant, which provides power to drive the automobile. In most automobile engines,the explosive power of the mixture of air and gasoline drives the pistons.The pistons turn a crankshaft to which they are attached The rotating force of the crankshaft makes the automobile’s wheels turn.Some automobiles are powered by another kind of engine,known as the rotary valve,rotating combustion engine or Wankel engine The rotary valve engine also draws in a mixture of air and fuel, which is then compressed and burnt.A motor revolving in an elliptical chamber is connected to a shaft,Which finally drives the rear wheels.In most automobiles.the engine is mounted at the front end of the car,with the clutch and gearbox immediately behind it;the engine, clutch and gearbox are assembled into a single unit Suspension System The function of the suspension system is to absorb vibrations due to the up and down motion of wheels.caused by the irregularities in the road surface . The springs, connecting linkages.and shock absorber comprise the suspension system of a vehicle.The suspension system is of two types: (1)Rigid system(2)Independent systemIn the rigid system, the road springs are attached to a rigid beam axle. It is mostly used in the front axle of commercial vehicles and in the car axle of all types of independent system does not have a rigid axle. Each wheel is free to move vertically without any reaction on its mating wheel. The independent system is mostly used in small cars Power TrainThe power train carries the power that the engine produces to the car wheels. It consists of the clutch (on cars with a manual transmission), transmission (a system of gears that increases the turning effort of the engine to move the automobile ),drive shaft, differential and rear clutch is required with the manual transmission system to temporarily disconnect the engine from wheels. Such disengagement of the power train from the engine is essential while changing the gear ratio or while stopping the main function of the transmission is to provide the necessary variation to the torque applied by the engine to the wheels. This is achieved by changing the gearing ratio between the engine output shaft and the drive ShaftThe drive shaft or propeller connects the gearbox and the differential unit. The drive shaft has universal joints at its ends.DifferentialThe function of the differential is to split the power received from the propeller shaft to the rear axle shaft. It allows the rear wheels to be driven at different speeds when the vehicle takes a bend or falls into a ditch. AxlesAxles are the shafts on which road wheels are mounted. The road wheels are provided with the required drive through these axles.WheelThe automobile wheels take the load of the vehicle and also produce tractive force to move the vehicle. The wheels are also used for retardation and for stopping the SystemThe steering system is used for changing the direction of the vehicle .The major requirements in any steering mechanism are that it should be precise and easy to handle, and that the front wheels should have a tendency to return to the straight-ahead position after a turn. A gear mechanism, which is known as steering gear, is used in this system to increase the steering effort provided by the driver. This system makes the vehicle steering very easy as the driver does not have to put in much effort.Vehicle steering is not only required on a curved road but also while maneuvering on the busy traffic roads.The steering system allows the vehicle to be guided i.e.to be turned left or right. Braking SystemBrakes are required for slowing down or stopping a moving vehicle.The braking system may be operated mechanically or hydraulically. 95 percent of the braking systems in use today are of the hydraulic brake consist of two members.one rotating and the other stationary.There are various means by which the two member call be brought in contact,thus reducing the speed of the major components of the braking system are:brake pedal, master cylinder, wheel Cylinder, brake pipe,brake shoes.brake packing plant and linkages.As the load on the vehicle and the vehicle speed has increased according to recent trends.in modem days, the importance of the braking system has also increased and power brakes are now being preferred.Power brakes utilize vacuum and air pressure to provide most of the brake————applying effort.汽车部件发动机发动机是一种动力机械设备.它为汽车提供动力。在大部分汽车发动机中.空气和汽油的混合气体产生的爆炸性能量驱动活动活塞运动。活塞使它们所连接的曲轴转动。曲轴的转动力量使汽车的车轮转动。一些汽车是由另外一种发动机提供动力的,这种发动机被认为是旋转气门、旋转燃烧或汪克尔发动机。转子发动机也是吸入空气和燃料的混合气,混合气被压缩和燃烧•在一个椭圆形的室内旋转的发动机连接着一个轴,这个轴将最终驱动后面的车轮。大部分汽车中,发动机是架在汽车的前面末端的,离台器和变速箱在它后面,发动帆、离台器和变速箱被装配成一个整体。发动机工作时有很多系统都是必要的。润滑系统可以减少摩擦并减轻发动机磨损。冷却系统被用来保持发动机的温度在安全范围内。发动机必须有燃油系统保证适当数量的空气和燃料供给。空气和燃油混合物必须由点火系统在适当的时间在气缸内被点燃。最后,电子系统被用来控制启动发动机用的电动机和为发动机附件提供电能。润滑系统发动机有许多最终会被磨损的运动部件,因为它们是相对运动的。发动机使润滑油在这些运动的部件间循环,以避免因金属与金属之间的接触而导致磨损。被润滑过的部件能够因为摩擦减少而容易运动,因摩擦导致的能量损失是最小的。润滑油的第二个功能是作为冷却液和防止泄露。最后,气缸壁上的润滑油薄膜有助于活塞环密封并因此提高发动机的压缩性。冷却系统 由于燃料与空气在气缸内燃烧,从而使发动机部件温度升高。温度升高直接影响发动机的性能和发动机部件的寿命。冷却系统使发动机工作保持在有效的温度。不管驾驶条件如何,发动机系统被设计成既能防止过热又能防止过冷。燃料供给系统燃料供给系统的主要功能是以一定的比例和压力给化油器或喷射系统提供燃料,并在汽车遇到的所有情况下,满足发动机对负载、速度和坡度的需要。燃料系统也必须为汽车行驶几英里保留足够的燃料。身提供了一个安装框架。车架用方刚或盒形钢铁制造,有足够的强度支撑车身和其他构件的重量。汽车车架通常由一些焊接或铆接在一起的零件构成,从而形成最后的形状。发动机和橡胶垫被圈定在车架上。橡胶垫可以吸收振动,也可以提供这些振动的阻尼减轻乘客由于振动产生的不适。悬架系统悬架系统的功能是吸收由于路面不平使车轮上下运动所产生的振动。弹性元件、连接装置和减振器组成了汽车的悬架系统。悬架系统有两种类型:(1)刚性悬架系统(2)独立悬架系统在刚性悬架系统中,弹簧被系在刚性横梁上,这种系统主要被用在商用车辆的前轴和所有类型车辆的车轴上。独立悬架系统没有一根坚硬的轴。每个车架可以自由做垂直运动而相对应的另一侧车轮没有任何反应。独立悬架系统主要用在小汽车上。传动系统传动系把发动机产生的能量传递给车轮。它包括离台器(汽车上用手动变速器)、传动系(一系列的齿轮,把由发动机产生的转矩增强.推动汽车)、驱动轴、差速器和后挢。离合器离合器用于手动变速的传动系统。用它暂时把发动机和车轮之间的动力传递分开。当换档或停车时,把传动系和发动机的连接断开是很必要的。变速籍变速箱的主要功能是通过发动机把各种必需的扭矩提供给车轮,这是通过改变发动机输出轴和驱动轴两者之阃的传动比来实现的。驱动轴驱动轴或叫推动轴与齿轮箱和差动器相连。驱动轴通常在末端具有万向节。差速器差速器的功能是把来自传动轴的能量分给后轿。当汽车转弯或掉沟时,它允许后轮以不同的逮度驱动。车轿车桥是指用来安装车轮的轴,通过这些车桥向车轮提供必需的驱动力。 车轮车轮支承着整辆车.并产生牵引力来驱动汽车。车轮也用于减速和停车。转向系统转向系统是用来改变汽车方向的,在任何转向机构中最主要的就是转向精确且容易控制,同时前轮在转向后又能自动回正。一个齿轮机构,通常认为是转向齿轮,在这个系统内用来增强由驾驶员提供的转向力,这个系统使得汽车转向非常容易,驾驶员不用费报大的力。不仅仅是在弯曲的公路上需要汽车转向,在交通拥挤的路上也需要巧妙地控制。转向系统使得汽车可以被控制向左或者向右转向。制动系统制动用来使车辆放慢速度或者停车。制动系统可以是机械制动或者液压制动。现在用的制动系统95%都是液压型的。所有的制动系统都包含两种元件,一种是旋转零件,另一种是固定零件,有各种各样方法使得这两个元件相接触而使车辆减速。制动系统的主要组成部分:制动踏扳、主制动缸、车轮制动、制动鼓、制动管路、制动蹄、制动装备和联动装置。随着汽车负载和车速的增大,目前制动系统的重要性也在增大,并且现在人们更喜欢助力制动。助力制动利用真空和空气压力来提供更好的制动力。
摘要- Cobots是一类机器人的使用不断 无级变速发展高保真可编程 约束的表面。 Cobots消耗很少的电力 即使在提供高输出部队,其传输效率高众多的 传动比。 Cobotic变速箱也有能力 采取行动作为一个制动器或将成为完全免费。设计 和性能Cobotic手控制器,最近 发达国家六自由度触觉显示器,是审查。 这个装置表明,高动态范围和低功耗 消费实现的cobots 。彻底的比较 电源效率cobotic系统与传统的 机电系统提供。 三个关键要求机器人技术用于 假肢和康复是低体重,低功耗 消费和安全性。我们建议cobotic技术作为 传输架构,可以处理这些问题。 Cobots是机器人利用非完整约束 的指导车轮的相对速度有关的 机制的联系。阿cobotic传播是一个不断 无级变速器(无级变速器)之间的积极和消极 比率,可以涉及两个平移速度,两个 旋转速度,或旋转速度为平移 速度[ 1 ] 。我们最近推出了Cobotic手 控制器(图1 ) ,六自由度动力 合作机器人,并阐述其能力作为触觉界面[ 2 , 3 ] 。通过本论文中,我们表明, 机械结构和传输中使用 Cobotic手控制器处理所有三个以上 上述要求的假肢和机器人 康复。
Abstract— Cobots是连续地使用机器人的类 开发高保真度可编程序的variable传输 constraint表面。 Cobots消耗很少电能 ,既使当提供高产力量和他们的传输横跨各种各样是非常有效率的transmission比率。 Cobotic传输也有能力 to作为闸或变得完全地自由。 设计 Cobotic手控制器的and表现,最近a developed六程度自由触觉显示,被回顾。 This设备说明高力学范围和低功率 consumption可达成由cobots。 彻底的比较 the一个cobotic系统的出力效率对常规 提供electro-mechanical系统。机器人技术的Three关键要求使用为 prosthetics和修复是低重量,低功率 consumption和安全。 我们提出cobotic技术作为a 可能论及所有这些问题的transmission建筑学。 Cobots是运用nonholonomic限制的机器人 of 操纵 轮子 关连 相对 速度 mechanism链接。 cobotic传输连续地是a variable传输(CVT)在正面和阴性之间 ratios, 并且 能 关连 二 平移 速度, 二 rotational速度或者对平移的旋转的速度 velocity [1]。 我们最近介绍了Cobotic手 Controller (图 1), a 供给动力的六程度自由 cobot和描述它的能力作为一个触觉接口[2, 3]。 通过本文路线,我们显示出, mechanical 建筑学 并且 传输 使用 在 Cobotic手控制器地址全部三在上面 机器人学的mentioned要求的弭补科和 rehabilitation.
IntroductionMachining aims to generate the shape of work-piece form a solid body,or to improve the tolerances and surface finish of a previously formed work-piece,by removing excess materials in the form of chips. Machining is capable of creating geometric configurations,tolerances, and surface finishes often unobtainable by any other , machining removes materials, which has already been paid for, in the form of relatively small particles that are more difficult to recycle and are in greater danger of becoming mixed. Therefore,developments often aim at reducing or-if at all possible-eliminating machining, especially in mass these reasons, machining has lost some important markets, yet, at the same time, it has also been developing and especially having captured new markets with the application of numerical feel for the important of machining may be gained from the observation that in 1983 there were about 2 million metal-cutting machine tools in the unite states ( of which some 5% were numerically controlled ) and that labor and overhead costs amounted to $125 billion, or 3% of the GNP.
基于UG的模块化机械设计方法研究摘 要]本文采用模块化设计思想和UG二次开发技术,解决了用UG软件进行机械设计时,许多常用件需要多次重新设计的问题。常用件模块以菜单的方式结合在UG软件中,这具有良好的可扩充性和可移植性。[关键词]模块化设计 机械设计 UG二次开发Unigraphics(简称UG)是美国EDS公司推出的CAD/CAM/CAE一体化软件。它的内容涉及到平面工程制图、三维造型、装配、制造加工、逆向工程、工业造型设计、注塑模具设计、钣金设计、机构运动分析、数控模拟、渲染和动化仿真、工业标准交互传输、有限元分析等十几个模块。近年来UG发展迅速,已广泛应用于多个领域,更是进行机械设计的常用软件。虽然UG功能非常强大,但在进行机械产品设计的时候经常会遇到一些标准件以外的常用件,若每次对它们均从头开始设计,则要做大量的重复性工作。为了提高劳动生产率,降低设计成本,将已经广泛应用于电子、计算机、建筑等领域的模块化设计思想引用到机械设计中,形成基于UG的模块化机械设计。1模块化机械设计模块及模块化的概念模块是一组具有同一功能和结合要素(指联接部位的形状、尺寸、连接件间的配合或啮合等),但性能、规格或结构不同却能互换的单元。模块化则是指在对产品进行市场预测、功能分析的基础上划分并设计出一系列通用的功能模块,然后根据用户的要求,对模块进行选择和组合,以构成不同功能或功能相同但性能不同、规格不同的产品。模块化机械设计相关性模块化设计所依赖的是模块的组合,即结合面,又称为接口。为了保证不同功能模块的组合和相同功能模块的互换,模块应具有可组合性和可互换性两个特征。这两个特征主要体现在接口上,必须提高模块标准化、通用化、规格化的程度。对于模块化机械设计,可见其关键是怎样划分模块,这里主要通过综合考虑零部件在功能、几何、物理上存在的相关性来划分模块。(1)功能相关性零部件之间的功能相关性是指在模块划分时,将那些为实现同一功能的零部件聚在一起构成模块,这有助于提高模块的功能独立性。(2)几何相关性零部件之间的几何相关性是指零部件之间的空间、几何关系上的物理联接、紧固、尺寸、垂直度、平等度和同轴度等几何关系。(3)物理相关性零部件之间的物理相关性是指零部件之间存在着能量流、信息流或物料流的传递物理关系。模块化机械设计的优点模块化机械设计在技术上和经济上都具有明显的优点,经理论分析和实践证明,其优越性主要体现在下述几方面:(1)可使现在机械工业得到振兴,并向高科技产业发展;(2)减轻机械产品设计、制造及装配专业技术人员的劳动强度;(3)模块化机械产品质量高、成本低,并且妥善解决了多品种小批量加工所带来的制造方面的问题;(4)有利于企业根据市场变化,采用先进技术改造产品、开发新产品;(5)缩短机械产品的设计、制造和供货期限,以赢得用户;(6)模块化机械产品互换性强,便于维修。2模块化机械设计在UG中的实现总体构思在用UG进行机械设计时,为了将常用件模块化,首先要把常用件的三维模型表达出来。对于系列产品,可按照成组技术的原理进行分类,一组相似的常用件建立一个三维模型,即所谓的三维模型样板。根据UG参数化设计思想,一个三维模型样板可认为是一组尺寸不同、结构相似的系列化零部件的基本模型。把众多的三维模型样板按类分开,每一类放在一个集合里,这样每类都形成了一个三维模型样板的模块库。为了使模块库与UG的集成环境有机地结合在一起,把每个模块库都以图标的方式放在用户菜单上,以方便调用。为了实现这一总体构思,综合运用了UG/Open MenuScript、UG/Open Ulstyler、UG/OpenAPI、Visual C++等UG二次开发技术,其程序流程图如图模块库菜单设计为了与UG菜单交互界面风格保持一致,模块库采用了分级式下拉菜单,下拉菜单通过UG/Open MenuScript模块开发实现。即利用MenuScript提供的UG菜单脚本语言,编写成扩展名为“.men”的文本文件,将其放在用户目录下的/startup目录内,通过设定UG的环境变量,UG在启动时会自动加载用户菜单文件。为了方便用户调用时快速检索到所要的常用件三维模型样板,将下拉菜单的最大深度设计为3级,且每一条下拉菜单最多不超过15个按钮。末级菜单上每一个按钮对应一个常用件三维模型样板名称,点击末级菜单按钮即调出创建相应产品的三维模型样板对话框。三维模型样板对话框设计利用UG/Open Ulstyle制作UG风格的对话框,按照模型样板的参数生成包含数据输入框、文本框、按钮、图片等控件的对话框。在对话框上部显示零配件图片,在对话框左上角显示对话框标题,在UG系统窗口左下角显示操作提示信息,这样可以使用户很方便地设计或选用常用件三维模型,三维模型样板对话框设计完成后,生成扩展名为“.dlg”文件。所有对话框都有6种基本同调函数,分别是Apply按钮的回调函数,Back按钮的回调函数、Cancel按钮的回调函数、OK按钮的回调函数、对话框构造函数和对话框析构函数。其中对话框构造函数在UG构建对话框完成之后、用户应用程序执行之前调用,将常用件三维模型的常用规格及技术要求显示到信息窗口,供用户创建产品时作参考。对话框析构函数在UG用户对话框关闭时调用,程序编写时利用它进行关闭、清除信息窗口以及释放申请的内存空间等操作。应用程序动态链接库(*.dll)创建UG/Open API应用程序是用C/C++语言编写的,它除了能够在UG的环境下对UG进行功能调用外,还能在程序中实现软件的文件管理、流程控制、数据传输、窗口调用、数值计算等C/C++语言支持的全部功能,使用非常灵活。UG/Open API应用程序牵涉到UG提供的头文件(*.h)、库文件(*.dll)及以C/C++语言编程环境,需要对Visual C++编译环境进行设置,下面给出了Visual C++编译环境设置方法及动态链接库的创建过程:(1)建立一个空的动态链接库工程。(2)配置程序头文件(*.h)、库文件(*.dll)的目录路径。其中头文件包括UG头文件,Visual C++库文件。(3)将对话框生成的C语言源文件模板文件*.添加到Project中。(4)编制应用程序。进入对话框回调函数内部进行程序编制,定义变量及UG对象,运用C/C++语言和UG/Open API函数进行参数化建模设计。(5)生成动态链接库(*.dll)文件。UG启动时会自动加载动态链接库文件,供用户菜单调用。3结束语随着装备制造业的飞速发展,产品种类急剧增多且结构日趋复杂,只有产品设计周期不断缩短,才能够满足企业激烈竞争的需要。用UG软件进行模块化机械设计符合机械产品快速设计的理念,符合装备制造业的发展需要,是机械设计的发展方向之一,具有较高的实用价值和经济价值。参考文献[1]袁峰UG机械设计工程范例教程[M]北京机械工业出版社2006[2]王志张进生于丰业王鹏任秀华基于模块化的机械产品快速设计[J]机械设计2004,21,8[3]滕晓艳张家泰产品模块化设计方法的研究[J]应用科技2006,33,2[4]董正卫田立中付宜利UG/Open API编程基础[M]北京清华大学出版社,2002 你自己用有道翻译吧!
IntroductionMachining aims to generate the shape of work-piece form a solid body,or to improve the tolerances and surface finish of a previously formed work-piece,by removing excess materials in the form of chips. Machining is capable of creating geometric configurations,tolerances, and surface finishes often unobtainable by any other , machining removes materials, which has already been paid for, in the form of relatively small particles that are more difficult to recycle and are in greater danger of becoming mixed. Therefore,developments often aim at reducing or-if at all possible-eliminating machining, especially in mass these reasons, machining has lost some important markets, yet, at the same time, it has also been developing and especially having captured new markets with the application of numerical feel for the important of machining may be gained from the observation that in 1983 there were about 2 million metal-cutting machine tools in the unite states ( of which some 5% were numerically controlled ) and that labor and overhead costs amounted to $125 billion, or 3% of the GNP.
Abstract— Cobots是连续地使用机器人的类 开发高保真度可编程序的variable传输 constraint表面。 Cobots消耗很少电能 ,既使当提供高产力量和他们的传输横跨各种各样是非常有效率的transmission比率。 Cobotic传输也有能力 to作为闸或变得完全地自由。 设计 Cobotic手控制器的and表现,最近a developed六程度自由触觉显示,被回顾。 This设备说明高力学范围和低功率 consumption可达成由cobots。 彻底的比较 the一个cobotic系统的出力效率对常规 提供electro-mechanical系统。机器人技术的Three关键要求使用为 prosthetics和修复是低重量,低功率 consumption和安全。 我们提出cobotic技术作为a 可能论及所有这些问题的transmission建筑学。 Cobots是运用nonholonomic限制的机器人 of 操纵 轮子 关连 相对 速度 mechanism链接。 cobotic传输连续地是a variable传输(CVT)在正面和阴性之间 ratios, 并且 能 关连 二 平移 速度, 二 rotational速度或者对平移的旋转的速度 velocity [1]。 我们最近介绍了Cobotic手 Controller (图 1), a 供给动力的六程度自由 cobot和描述它的能力作为一个触觉接口[2, 3]。 通过本文路线,我们显示出, mechanical 建筑学 并且 传输 使用 在 Cobotic手控制器地址全部三在上面 机器人学的mentioned要求的弭补科和 rehabilitation.
摘要- Cobots是一类机器人的使用不断 无级变速发展高保真可编程 约束的表面。 Cobots消耗很少的电力 即使在提供高输出部队,其传输效率高众多的 传动比。 Cobotic变速箱也有能力 采取行动作为一个制动器或将成为完全免费。设计 和性能Cobotic手控制器,最近 发达国家六自由度触觉显示器,是审查。 这个装置表明,高动态范围和低功耗 消费实现的cobots 。彻底的比较 电源效率cobotic系统与传统的 机电系统提供。 三个关键要求机器人技术用于 假肢和康复是低体重,低功耗 消费和安全性。我们建议cobotic技术作为 传输架构,可以处理这些问题。 Cobots是机器人利用非完整约束 的指导车轮的相对速度有关的 机制的联系。阿cobotic传播是一个不断 无级变速器(无级变速器)之间的积极和消极 比率,可以涉及两个平移速度,两个 旋转速度,或旋转速度为平移 速度[ 1 ] 。我们最近推出了Cobotic手 控制器(图1 ) ,六自由度动力 合作机器人,并阐述其能力作为触觉界面[ 2 , 3 ] 。通过本论文中,我们表明, 机械结构和传输中使用 Cobotic手控制器处理所有三个以上 上述要求的假肢和机器人 康复。
英文部分 Rotary pumps These are built in many different designs and are extremely popular in modern fluid-power system. The most common rotary-pump designs used today are spur-gear, generated-rotary , sliding-vane ,and screw pump ,each type has advantages that make it the most suitable for a given application .Spur-gear pumps. these pumps have two mating gears are turned in a closely fitted casing. Rotation of one gear ,the driver causes the second ,or follower gear, to turn . the driving shaft is usually connected to the upper gear of the pump .When the pump is first started ,rotation of gears forces air out the casing and into the discharge pipe. this removal of air from the pump casing produces a partial vacuum on the pump inlet ,here the fluid is trapped between the teeth of the upper and lower gears and the pump casing .continued rotation of the gears forces the fluid out of the pump discharge .Pressure rise in a spur-gear pump is produced by the squeezing action on the fluid ad it is expelled from between the meshing gear teeth and casing ,.a vacuum is formed in the cavity between the teeth ad unmesh, causing more fluid to be drawn into the pump ,a spur-gear pump is a constant-displacement unit ,its discharge is constant at a given shaft speed. the only way the quantity of fluid discharge by a spur-gear pump of type in figure can be regulated is by varying the shaft speed .modern gear pumps used in fluid-power systems develop pressures up to about shows the typical characteristic curves of a spur-gear rotary pump. These curves show the capacity and power input for a spur-gear pump at various speeds. At any given speed the capacity characteristic is nearly a flat line the slight decrease in capacity with rise in discharge pressure is caused by increased leakage across the gears from the discharge to the suction side of the pump. leakage in gear pumps is sometimes termed slip. Slip also increase with arise pump discharge pressure .the curve showing the relation between pump discharge pressure and pump capacity is often termed the head-capacity or HQ curve .the relation between power input and pump capacity is the power-capacity or PQ curve .Power input to a squr-gear pump increases with both the operating speed and discharge pressure .as the speed of a gear pump is increased. Its discharge rate in gallons per minute also rise . thus the horsepower input at a discharge pressure of 120psi is 5hp at 200rpm and about 13hp at corresponding capacities at these speed and pressure are 40 and 95gpm respectively, read on the 120psi ordinate where it crosses the 200-and 600-rpm HQ curves .Figure is based on spur-gear handing a fluid of constant viscosity , as the viscosity of the fluid handle increases (. ,the fluid becomes thicker and has more resistance to flow ),the capacity of a gear pump decreases , thick ,viscous fluids may limit pump capacity t higher speeds because the fluid cannot into the casing rapidly enough fill it completely .figure shows the effect lf increased fluid biscosity on the performance of rotary pump in fluid-power system .at 80-psi discharge pressure the pp has a capacity lf 220gpm when handling fluid of 100SSU viscosity lf 500SSU . the power input to the pump also rises ,as shown by the power lf rotary pump is often expressed in gallons per revolution of the gear or other internal element .if the outlet of a positive-displacement rotary pump is completely closed, the discharge pressure will increase to the point where the pump driving motor stalls or some part of the pump casing or discharge pipe ruptures .because this danger of rupture exists systems are filled with a pressure –relief valve. This relief valve may be built as of the pump or it may be mounted in the discharge PumpsThese pumps have a number of vanes which are free to slide into or out of slots in the pup rotor . when the rotor is turned by the pump driver , centrifugal force , springs , or pressurized fluid causes the vanes to move outward in their slots and bear against the inner bore of the pump casing or against a cam ring . as the rotor revolves , fluid flows in between the vanes when they pass the suction port. This fluid is carried around the pump casing until the discharge port is reached. Here the fluid is forced out of the casing and into the discharge the sliding-vane pump in Figure the vanes in an oval-shaped bore. Centrifugal force starts the vanes out of their slots when the rotor begins turning. The vanes are held out by pressure which is bled into the cavities behind the vanes from a distributing ring at the end of the vane slots. Suction is through two ports A and AI, placed diametrically opposite each other. Two discharge ports are similarly placed. This arrangement of ports keeps the rotor in hydraulic balance, reliving the bearing of heavy loads. When the rotor turns counterclockwise, fluid from the suction pipe comes into ports A and AI is trapped between the vanes, and is carried around and discharged through ports B and BI. Pumps of this design are built for pressures up to 2500 psi. earlier models required staging to attain pressures approximating those currently available in one stage. Valving , uses to equalize flow and pressure loads as rotor sets are operated in series to attain high pressures. Speed of rotation is usually limited to less than 2500rpm because of centrifugal forces and subsequent wear at the contact point of vanes against the cam-ring surface.. Two vanes may be used in each slot to control the force against the interior of the casing or the cam ring. Dual vanes also provide a tighter seal , reducing the leakage from the discharge side to the suction side of the pump . the opposed inlet and discharge port in this design provide hydraulic balance in the same way as the pump, both these pumps are constant-displacement delivery or capacity of a vane-type pump in gallons per minute cannot be changed without changing the speed of rotation unless a special design is used. Figure shows a variable-capacity sliding-vane pump. It dose not use dual suction and discharge ports. The rotor rums in the pressure-chamber ring, which can be adjusted so that it is off-center to the rotor. As the degree of off-center or eccentricity is changed, a variable volume of fluid is discharged. Figure shows that the vanes create a vacuum so that oil enters through 180 of shaft rotation. Discharge also takes place through 180 of rotation. There is a slight overlapping of the beginning of the fluid intake function and the beginning of the fluid shows how maximum flow is available at minimum working pressure. As the pressure rises, flow diminishes in a predetermined pattern. As the flow decreases to a minimum valve, the pressure increases to the maximum. The pump delivers only that fluid needed to replace clearance floes resulting from the usual slide fit in circuit relief valve is not essential with a variable-displacement-type pump of this design to protect pumping mechanism. Other conditions within the circuit may dictate the use of a safety or relief valve to prevent localized pressure buildup beyond the usual working automatic control of the discharge , an adjustable spring-loaded governor is used . this governor is arranged so that the pump discharge acts on a piston or inner surface of the ring whose movement is opposed by the spring . if the pump discharge pressure rises above that for which the by governor spring is set , the spring is compressed. This allows the pressure-chamber ring to move and take a position that is less off center with respect to the rotor. The pump theb delivers less fluid, and the pressure is established at the desired level. The discharge pressure for units of this design varies between 100 and characteristics of a variable-displacement-pump compensator are shown in figure. Horsepower input values also shown so that the power input requirements can be accurately computed. Variable-volume vane pumps are capacity of multiple-pressure levels in a predetermined pattern. Two-pressure pump controls can provide an efficient method of unloading a circuit and still hold sufficient pressure available for pilot black area of the graph of figure shows a variable-volume pump maintaining a pressure of 100psi against a closed circuit. Wasted power is the result of pumping oil at 100psi through an unloading or relief valve to maintain a source of positive pilot pressure. Two-pressure –type controls include hydraulic, pilot-operated types and solenoid-controlled, pilot-operated types. The pilot oil obtained from the pump discharge cannot assist the governor spring. Minimum pressure will result. The plus figure shows the solenoid energized so that pilot oil assists compensator spring. The amount of assistance is determined by the small ball and spring, acting as a simple relief valve. This provides the predetermined maximum operating type of two-pressure system employs what is termed a differential unloading governor. It is applied in a high-low or two-pump circuit. The governor automatically, Through pressure sensing, unloads the large volume pump to a minimum deadhead pressure setting. Deadhead pressure refers to a specific pressure level established as resulting action of the variable-displacement-pump control mechanism. The pumping action and the resulting flow at deadhead condition are equal to the leakage in the system and pilot-control flow requirements. No major power movement occurs at this time, even though the hydraulic system may be providing a clamping or holding action while the pump is in deadhead position The governor is basically a hydraulically operated, two-pressure control with a differential piston that allows complete unloading when sufficient external pilot pressure is applied to pilot unload minimum deadhead pressure setting is controlled by the main governor spring A. the maximum pressure is controlled by the relief-valve adjustment B. the operating pressure for the governor is generated by the large-volume pump and enters through orifice C. To use this device let us assume that the circuit require a maximum pressure of 1000psi, which will be supplied by a 5-gpm pump. It also needs a large flow (40gpm) at pressure up to 500psi; it continues to 1000pso at the reduced flow rate. A two-pump system with an unloading governor on the 40-gpm pump at 500psi to a minimum pressure setting of 200psi (or another desired value) , which the 5-gpm pump takes the circuit up to1000psi or in figure that two sources of pilot pressure are required. One ,the 40-gpm pump, provides pressure within the housing so that maximum pressure setting can be obtained. The setting of the spring, plus the pressure within the governor housing, determines the maximum pressure capacity of the 40-gpm pump. The second pilot source is the circuit proper, which will go to 1000psi. this pilot line enters the governor through orifice D and acts on the unloading piston E . the area of piston E is 15 percent greater than the effective area of the relief poppet F. the governor will unload at 500psi and be activated at 15percent below 500psi, or 425psi. By unloading, we mean zero flow output of the 40-gpm pressure in the circuit increases from zero to 500psi, the pressure within the governor housing also increases until the relief-valve setting is reached, at which time the relief valve cracks open, allowing flow to the pressure drop in the hosing is a maximum additive value, allowing the pump to deadhead. Meanwhile, the system pressure continues to rise above 700psi, resulting in a greater force on the bottom of piston E than on the top. The piston then completely unseats poppet F, which results in a further pressure drop within the governor horsing to zero pressure because of the full-open position of the relief poppet F. flow entering the housing through orifice is directed to the tank pass the relief poppet without increasing the pressure in housing. The deadhead pressure of the 40-gpm pump then decreases to the lower set value. Thus , at the flow rate to the unloading governor ,the 40gpm pump goes to deadhead. The flow rate to the circuit decreases to 5gpm as the pressure to 1000psi, the 5-gpm pump is also at its deadhead setting, thus only holding system 4-gpm pump unloads its volume at 500psi. It requires a system pressure of 600psi to unload the 40-gpm pump to its minimum pressure of 200psi. the 600-psi pilot supply enters through orifice D and acts on the differential piston E. The pumps volume is reduced to zero circuit-flow output at 500psi. The additional 100-psi pilot pressure is required to open poppet F completely and allow the pressure within the housing to decrease to circuit pressure decreases ,both pumps come back into service in a similar pattern.
毕业论文的英文翻译是thesis,音标是英[ˈθi:sɪs] 美[ˈθisɪs] 。thesisn.论文,毕业论文;论点,论题;命题扩展例句1、There is no empirical evidence to support his thesis. 他的论文缺乏实验证据的支持。2、How well does this thesis stand up to close examination? 这个命题经得起推敲吗?3、He has finished his thesis. 他的论文完成了。4、She's finished writing her thesis. 她那篇论文写出来了。5、Please write an abstract of this article 〔 thesis 〕. 请写一份这本书〔这篇论文〕的摘要。The article has a clear-cut thesis and arguments, but lacks reasoning.文章论点、论据鲜明,但缺乏论证。
He was awarded his PhD for a thesis on industrial robots.
他凭一篇研究工业机器人的论文获得博士学位。
Please write an abstract of this article 〔 thesis 〕.
请写一份这本书〔这篇论文〕的`摘要。
Your thesis wouldn't get across if you used too many technical terms in it.
如果你用了过多的专门术语,你的论文就不会被人理解。
He is writing his doctoral thesis in electrical engineering.
他在写关于电气工程学的博士论文。
Thesis For Graduation毕业论文Thesis For Academic Degree学位论文Thesis表示比较严肃的文章,是带有一定目的的,研究性的文章。学位论文,研究报告。
A Thesis Submitted as a Partial Fulfillment of the Requirement for the Degree of B. A./B. S. in ***这是标准的学士学位毕业论文的说法,.代表文学学士,.代表理学学士,***处填上专业。