Hand lay-up: 14.04.2011 10.40
Hand lay-up is the oldest open mold method for FRP laminates, dating to the 1940s when it was first used to fabricate boat hulls. It is also the most labor-intensive method. As the name suggests, hand lay-up is a shaping method in which successive layers of resin and reinforcement are manually applied to an open mold to build the laminated FRP composite structure. The basic procedure consists of five steps, illustrated in Figure 15.4. Tire finished molding must usually be trimmed with a power saw to size the outside edges. In general, these same five steps are required for all of the open mold processes; the differences between methods occur in steps 3 and 4, as we shall see.
In step 3, each layer of fiber reinforcement is dry when placed onto the mold. The liquid (uncured) resin is then applied by pouring, brushing, or spraying. Impregnation of resin into the fiber mat or fabric is accomplished by hand rolling. This approach is referred to as wet lay-up. An alternative approach is to use prepregs, in which the impregnated layers of fiber reinforcement are first prepared outside the moid and then laid onto the mold surface. Advantages cited for the prepregs include closer control over fiber-resin mixture and more efficient methods of adding the laminations.
(Mikell P. Groover,Fundamentals of Modern Manufacturing,4th Edition,pg.324)
Multiple-Cutting-Edge Tools 15.04.2011 20.40
Most multiple-cutting-edge tools are used in machining operations in which the tool is rotated. Primary examples are drilling and milling. On the other hand, broaching and some sawing operations (hacksawing and bandsawing) use muitiple-cutiing-edge tools that operate with a linear motion. Other sawing operations (circular sawing) use rotating saw blades.
(Mikell P. Groover,Fundamentals of Modern Manufacturing,4th Edition,pg.562)
Electrohydraulic Forming 15.04.2011 20.55
Electrohydraulic forming is a HERF process in which a shock wave to deform the work into a die cavity is generated by the discharge of electrical energy between two electrodes submerged in a transmission fluid (water). Owing to its principle of operation, this process is also called electric discharge forming. The setup for the process is illustrated in Figure 20.46. Electrical energy is accumulated in large capacitors and then released to the electrodes. Electrohydraulic forming is similar to explosive forming. The difference is in the method of generating the energy and the smaller amounts of energy that are released. This limits electrohydraulic forming to much smaller part sizes.
(Mikell P. Groover,Fundamentals of Modern Manufacturing,4th Edition,pg.473-474)
Tube Spinning 15.04.2011 21.04
Tube spinning is used to reduce the wall thickness and increase the length of a tube by means of a roller applied to the work over a cylindrical mandrel, as in Figure 20.44. Tube spinning is similar to shear spinning except that the starting workpiece is a tube rather than a flat disk. The operation can be performed by applying the roller against the work externally (using a cylindrical mandrel on the inside of the tube) or internally (using a die to surround the tube), it is also possible to form profiles in the walls of the cylinder, as in Figure 20.44(c), by controlling the path of the roller as it moves tangentially along the wall.
(Mikell P. Groover,Fundamentals of Modern Manufacturing,4th Edition,pg.472)
for multiple-cutting-edge tools:
ReplyDeleteYou explained only utilization area of multiple-cutting-edge tools.
If you take full point, you have to explain some properties of multiple-cutting-edge tools.
clue: you should use this book. Notice that edition number
(Mikell P. Groover,Fundamentals of Modern Manufacturing,3th Edition, page 485)
tube spinning ve electrohydraulic forming terimlerinde figure diye atıfta bulunduğun figürleri göremiyorum. Ya o cümleleri kaldır yada figürleri ekle. Ayrıca bu terimlerin ikisi de başka kişiler tarafından da cevaplanmış, dolayısıyla şu an için hiçbirinize puan veremeyeceğim.
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