Computer Aided Process Planning (mechanical seminar topics)

SUMMARY/INTRODUCTION

Technological advances are reshaping the face of manufacturing, creating paperless manufacturing environments in which computer automated process planning (CAPP) will play a preeminent role. The two reasons for this effect are: Costs are declining, which encourages partnerships between CAD and CAPP developers and access to manufacturing data is becoming easier to accomplish in multivendor environments. This is primarily due to increasing use of LANs; IGES and the like are facilitating transfer of data from one point to another on the network; and relational databases (RDBs) and associated structured query language (SQL) allow distributed data processing and data access.
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With the introduction of computers in design and manufacturing, the process planning part needed to be automated. The shop trained people who were familiar with the details of machining and other processes were gradually retiring and these people would be unavailable in the future to do process planning. An alternative way of accomplishing this function was needed and Computer Aided Process Planning (CAPP) was the alternative. Computer aided process planning was usually considered to be a part of computer aided manufacturing. However computer aided manufacturing was a stand alone system. Infact a synergy results when CAM is combined with CAD to create a CAD/CAM. In such a system CAPP becomes the direct connection between design and manufacturing.

Moreover, the reliable knowledge based computer-aided process planning application MetCAPP software looks for the least costly plan capable of producing the design and continuously generates and evaluates the plans until it is evident that non of the remaining plans will be any better than the best one seen so far. The goal is to find a useful reliable solution to a real manufacturing problem in a safer environment. If alternate plans exist, rating including safer conditions is used to select the best plans

WHAT IS CAD?

A product must be defined before it can be manufactured. Computer Aided Design involves any type of design activity that makes use of the computer to develop, analyze or modify an engineering design. There are a number of fundamental reasons for implementing a computer aided design system.
a. Increase the productivity of the designer: This is accomplished by helping the designer to visualize the product and its component subassemblies and parts; and by reducing the time required in synthesizing, analyzing, and documenting the design. This productivity improvement translates not only into lower design cost but also into shorter project completion times.
b. To improve the quality of the design: A CAD system permits a more thorough engineering analysis and a larger number of design alternatives can be investigated. Design errors are also reduced through the greater accuracy provided by the system. These factors lead to a better design.
c. To improve communications: Use of a CAD system provides better engineering drawings, more standardization in the drawings, better documentation of the design, fewer drawing error, and greater legibility.
d. To create a database for manufacturing: In the process of creating a the documentation for the product design (geometries and dimensions of the product and its components, material specification for components, bill of materials etc), much of the required data base to manufacture the product is also created.

Design usually involves both creative and repetitive tasks. The repetitive tasks within design are very appropriate for computerization.

Mine Detection Using Radar Bullets(Mechanical seminar topic)

SUMMARY

Now a day in places like Afghanistan and Iraq we know that land mines are causing serious threat to the lives of civilians. The mines that are implanted during the wartime may remain undetected for several decades and may suddenly be activated after that. Also during wartime mines implanted by our enemy countries are to be detected and diffused properly in order to save the lives of our soldiers. So we should say that detecting landmines is important for every country today.

AFFECTION

The countries known to have severe landmine problems are Afghanistan, Bosnia, Cambodia, Ethiopia, Vietnam, Iraq, Kuwait, Laos, Egypt, Eritrea, Chevalier, China. Unfortunately India, Pakistan, Srilanka, Myanmar are in the list of less mine affected countries besides other 100 countries.

LAND MINE>>>>>>>

The purpose of a landmine is to disable, immobilize or kill. It is an explosive device activated either by a person or vehicle or by command detonated by electric wire or radio signals. Most land mines are laid on just below the surface of ground and are activated by pressure or trip-wire. Usually most of the land mines will contain many metallic parts, which can be made use of in their detection.

Anti-personal mines claims 70 new victims every day. This weapon is particularly cruel on children whose bodies being smaller and closer to the blast are more likely to sustain serious injury. The severe disabilities and psychological traumas that follow the blast- means these children will have to be looked after for many years.

A child injured at the age of 10 will need about 25 critical limbs during there life time. This cost in 3000 Dollars a huge sum to pay in countries where people earn as little as 10 dollar a month. . Between 1979 of 1996 the red crores fitted over 70,000 amputees with critical limbs and the land mine problem in still growing. There for considering these factors the discovery of radar bullet is really a big boost to our world as we launches to 21st century.

RADAR BULLET

The radar bullet is a special type of bullet. The main use of radar bullet is to find landmines without setting foot on the ground. This consists of firing a special bullet in to the ground from a helicopter, which could pin point buried land mines.

The bullet units a radar pulse as it grounds to a halt. This pulse strikes the mine and its image gets available on the computer in the helicopter, offering a safe and efficient way of finding land mines

Apache Helicopter(mechanical seminar topics)

summary
The Apache Helicopter is a revolutionary development in the history of war. It is essentially a flying tank- a helicopter designed to survive heavy attack and inflict massive damage. It can zero in on specific targets, day or night, even in terrible weather. As you might expect, it is a terrifying machine to ground forces.

In this topic, we look at the Apache's amazing flight systems, engines, weapon systems, sensor systems and armour systems. Individually these components are remarkable pieces of technology. Combined together they make up an unbelievable fighting machine - the most lethal helicopter ever created.

HISTORY

The first series of Apaches, developed by Hughes Helicopters in the 1970s, went into active service in 1985. The U.S military is gradually replacing this original design, known as the AH-64A Apache, with the more advanced AH-64D Apache Longbow. In 1984, Mc Donnell Douglas purchased Hughes Helicopters, and in 1997, Boeing manufactures Apache helicopters, and the UK-based GKN Westland helicopters manufacturers the English versions of the Apache, the WAH-64.

DRAG: Drag is an aerodynamic force that resists the motion of an object moving through a fluid. The amount of drag depends on a few factors, such as the size of the object, the speed of the car and the density of the air.

THRUST: Thrust is an aerodynamic force that must be created by an airplane in order to overcome the drag. Airplanes create thrust using propellers, jet engines or rockets.

WEIGHT: This is the force acting downwards or the gravitational force.

LIFT: Lift is the aerodynamic force that holds an airplane in the air, and is probably the important of the four aerodynamic forces. Lift is created by the wings of the airplane.

Lift is a force on a wing immersed in a moving fluid, and it acts perpendicular to the flow of the fluid but drag is the same thing, but acts parallel to the direction of the fluid flow.

1. Air approaching the top surface of the wing is compressed into the air above it as it moves upward. Then, as the top surface curves downward and away from the air stream, a low pressure area is developed and the air above is pulled downward toward the back of the wing.
2. Air approaching the bottom surface of the wing is slowed, compressed and redirected in a downward path. As the air nears the rear of the wing, its sped and pressure gradually match that of the air coming over the top. The overall pressure effects encountered on the bottom of the wing are generally less pronounced than those on the top of the wing.

3.1 FOR STRAIGHT AND LEVEL FLIGHT

The following relationships must be true:
THRUST = DRAG
WEIGHT = LIFT

If for any reason, the amount of drag becomes larger then the amount of thrust, the plane will slow down. If the thrust is increased so that it is greater than drag, the plane will speed up.

If the amount of lift drops below the weight of the airplane, the plane will descend. By increasing the lift, the pilot can make the airplane climb