Cem Ertürk-030070245-6th week answers

BSFC ( Term About Fuel Consumption on The Car)


Brake specific fuel consumption (bsfc) is a measure
of the effectiveness of an engine’s ability to
convert the chemical energy in the fuel into useful
work. Brake specific fuel consumption is calculated
as shown, for example
bsfc = (mass of fuel consumed per hour)/(brake power)
(Allan Bonnick, Automotive Science and Mathematics, pg. 166)


BSFC (better and new)



Fuel economy is dependent on ongine operating poim and lotal road load given by. Fuel economy is calculated from knowledge of the engine power at on crankshaft, its resultant brake specific fuel consumption. BSI,. and specific gravity of. fuel at ale prevailing conditions. In general. the filet specific gravity is assumed constant for the drive cycle. Engine power is determined by extrapolating operating 

points on an onion plot of engine power output versus speed for constant BSFC contours. Contours of constant BSFC are determined empirically by laboratory characterisation of given engine at various torque-speed points. Engine power given crankshaft torque (Nm) and speed in either rad/s or rpm iswhere vehicle speed, V, is in mks units of m/s, specific fuel consumption BSFC is given as g/kWh, specific gravity in g/cm^3, and engine power in kW.

 (Miller J. M. Propulsion Systems for Hybrid Vehicles, page:34)

( I think my definition is better than old one. Because It is include to much detail and explain totally)

Ultrasonic Spot Welding ( Manufacturing Technique)


Ultrasonic spot welding joins two thermoplastic parts at localized points without a preformed hole or energy director. It produces a strong structural weld and is especially suitable for large parts with complicated geometry or hard to reach joining surfaces. Spot welding lends itself to sheets of extruded or cast thermoplastic and is often used on vacuum-formed parts, such as blister (clamshell) packaging.


(Plastics Design Library, Handbook of Plastics Joining: A Practical Guide, p.61)

Ultrasonic Spot Welding ( New and beter)




Ultrasonic spot welding is a technique commonly used to weld relatively thick thermoplastik sheets (+ 4 mm). As the name implies, the resulting weld is located at a single spot. Because of this. the final seal is not continues and iiiit hermetic However, in many applica-tions. this type of mint is sufficient for the final application design. Spot welding has the advantage that often the equipment can be relatively simple: hand-held welding qstems can be used in many of these application, In addition, the applications do not require any Joint design. allowing welds to be made at any location between two sheets.


 The final joint configuration is defined by the spot welding tip. The tip design is usually based on the thickness of the top sheet to he welded. Figure 8.26 sleeve tyqwpical cross-sections of tip designs and the general dimensions based on lop shod thickness (T)


 It is important to note that the final weld is limited to an area near the center of the spot weld. That is to say. very little adhesion is obtained away 1mm the spot welding up. This can beacon in Fig. 8.27, which illustrates a typical cross-section of spot weld. It is also important to note that there is no adhesion at the center of the spot weld. where the tip actually protrudes through the entire thickness of the top sheet.

( Benatar A. Plastics and composites welding handbook, 10. cilt page:168)


( Clearly seen that my definition is best. I give example about term and explained every detail about this manufacturing technique)

Induction Welding (Manufacturing Technique)


Induction welding uses induction heating from high radio frequency alternating current to magnetically excite ferromagnetic particles embedded in a bonding agent (with a thermoplastic or matrix) placed at the joint interface of the two parts being welded. The heat released is used to melt and fuse thermoplastics, to heat hotmelt adhesives, or to provide rapid adhesive cures for thermosets. It is a reliable and rapid technique, ranging from fractions of a second for small parts to 30-60 seconds for parts with long (400 cm; 157 in.) bond lines, and results in structural, hermetic, or high- pressure welds.


(Plastics Design Library, Handbook of Plastics Joining: A Practical Guide, p.67)


Induction Welding( New and Better)


In induction welding coalescence is produced by the heat obtained from the resistance of the weldment to the flow of an induced electrical current. Pressure is frequently used to complete the weld. The inductor coil is not in contact with the weldment ; the current is induced into theconductive material. Resistance of the material to this current flow results in the rapid generation of heat. In operation a high current is induced into both edges of the work close to where the weld is to be made. Heating to welding temperature ft extremely rapid and the joint in completed by pressure rolls or contorts. 
          Vacume tube oscillators arc the source of power for most high frequency welding.
- Induction welding can be used for most metals and has been succesfully employed for some dissimilar metals.


Applications:


- Butt and seam welding of pipe, sealing containers;
-Welding expanded metal;
-Fabricating various structural shapes.

(Rajput R. K.  A textbook of manufacturing technology: (manufacturing processes)  page:324)


(My definitions is the best. Because old one is mentioned about how is doing mostly. But mine is talking about what is it and this technique used what type of material)

Vibration Welding (Manufacturing Technique)


vibration welding is a well-established process that can join large,sealed, and mechanically strong weld seams with cycle times of only a few seconds.It is mainly used when short cycle times are demanded and the part is too large for the use of ultrasonic welding.However, because the process reqires relatively flat (planner) joining surfaces, some applications are not suited for vibration welding.A slight incline in the jint 10 degree can be tolerated in the linear vibration welding components, although it is not recommended.in some cases the vibration welding process can be used to solve warpage issues of glass-fiber-filled polyamide parts, because it is possible to clamp the parts,so that they are forced in the correct geometry.vibration welding can also used as an alternative to adhering or mechanically joining different materials such as wood fiber reinforced matherials to thermoplastic.
ın vibration welding, the two parts to be joined are clamped together under a relatively high force.At a preset force, one part is vibrated relative to the seconf, usually with a displacement between 0.5 and 1.5 mm (0.020 and 0.060 in.). The motion results in the joining surface melting and fusing together.
(Avraham Benatar, Welding, p.36)

Vibration Welding( New )

Vibration welding uses heat generated by fliction m the interface of two materials lo produce melting in the interfacial area. The molten materials flow together under pressure. forming a weld upon cooling. Vibration welding can be accomplish,. in a short time (1-10 .conds cycle time) and is applicable to a vaiicly of thcr-inopla,tic pans with planar or slightly curved surface,. The two main types of vibration welding are: ear. in which friction is generated by a linear. recipro-cating motion (Fig. 3.1 ). and orbital, in which the upper part to be joined is vibrated in a circular motion. Linear vibration welding is most commonly used, but orbital vibration welding makes the welding of irregularly shaped plastic parts possible.


 Process parameters arc the amplitude and frequency of vibration, weld pressure. and weId time, all of which affect the strength of the resulting weld. 

(Troughton M.J.  Handbook of Plastics Joining: A Practical Guide, page:37 )

(Honestly said that two of definition had same value if i would gave a score. These definitions are like praphrasing to other one.)

Plastic Alloy ( Material Type )


The principle o alloying plastics is similar to that of alloying metals- to achive in one material the advantages possessed by several others. The recent increased interest and activity in the field of polymer alloys has occured as a result of several new factors. One is the development of more sophisticated techniques for combining plastics which were previously considered to be incompatible. Another is the keen competition for a share of new market areas such as automobile bumpers, body panels etc. These applications call for combinations of properties not previously available in a single plastic and it has been found that it is less expensive to combine existing plastics than to develop a new monomer on which to base the new plastic. Typical plastic alloys : PVC/Acrylic, PVC/ABS, Polycarbonate /ABS, ABS/ Polysulphone, Nylon/elastomer. (Plastic Engineering - R.J. Crawford- page 11 )


Plastic Alloy ( New and Better)



TM development of new polymer alloys h. caused a lot of excitement in recent years but in fact Mc concept has been around for a long time. Weed one of the major commercial successes of today, ABS. is in fact m alloy of acrylonitrile, butadiene and styrene. The principle of alloying plastics is similar to that of alloying metals - to achieve in one material the advantages possessed by several others. Tbe resent increased interest and activity in the field of polymer alloys h. occurred as a result of several new factors. One is the development of more sophirticated tecbniques for combining plastics which were previously considered to be incompatible. Another is the keen competition for a share of new market areas such as automobile bumpers, body panels etc. These applications call for combinations of properties not previously available in a single plastic and it has been found that it is less expensive combine existing plastics than to develop a new monomer on which to base the new plastic.


In designing an alloy, polymer chemists choose candidate resins according to the properties, cos, and/or processing characteristics required in Me end product. Next, compatibility of the constituents is studied. tem.. and eiMer optimised or accommodated.

Certain polymers have come to be considered standard Minding blocks of Me polyblends. For example. impact firength may be improved by using polycarbonate. ABS and polyurethanes. Heat resistance is improved by using polyMenylene oxide, polysulphone, INC, polyester (PET and PM) and acrylic. Barrier properties are improved by using plastics such as eMyMne vinyl alchol (EVA). Some modem plastic alloys and their main charterisctics are given in Table 1.2. 

(Crawford R.J.  Plastic Engineering, Page:11)

(My definition is best. Because older one axplain the definiton with example way.It can be true but it is not enough to understand what it is and can't imagine what is it like. Explanition of definition need to be example in life. So my definition has a table about plastic alloy and showed us what is used for and what kind of advantages give to using them)