Reading and comprehension exercises. Exercise 1. First read the following text about the metal joints quickly to get the main ideaExercise 1. First read the following text about the metal joints quickly to get the main idea. The words missing from each passage are the names of the joint types. Can you identify the metal joints described?
1. _________s are one of the most common elements in construction and machine design. They consist of fasteners that capture and join other parts, and are secured with the mating of screw threads. There are two main types of _________ designs. In one method the bolt is tightened to a calculated clamp load, usually by applying a measured torque load. The joint will be designed such that the clamp load is never overcome by the forces acting on the joint (and therefore the joined parts see no relative motion). The other type of _________ does not have a designed clamp load but relies on the shear strength of the bolt shaft. This may include clevis linkages, joints that can move, and joints that rely on a locking mechanism (like lock washers, thread adhesives, and lock nuts). 2. _________s are ridges or teeth on a drive shaft that mesh with grooves in a mating piece and transfer torque to it, maintaining the angular correspondence between them. For instance, a gear mounted on a shaft might use a male _________ on the shaft that matches the female _________ on the gear. The _________s on the drive shaft match with the female _________s in the center of the clutch plate, while the smooth tip of the axle is supported in the pilot bearing in the flywheel. An alternative to _________s is a keyway and key, though _________s provide a longer fatigue life. 3. A _________ or _________ is a fastening mechanism consisting of a male side with one or more pins, and a female receptor with matching L slots and spring(s) to keep the two parts locked together. To couple the two parts, the pin(s) on the male are aligned with the slot(s) on the female and the two pushed together. Once the pins reach the bottom of the slot, the two parts are turned in opposite directions to guide the pin across the bottom of the L shaped slot. The spring then holds the pin in position to prevent it from backing out. To disconnect, the two parts are pushed together to overcome the spring whilst twisting slightly to reverse the locking turn. The strength of the joint relies on the shear strength of the pins and the strength of the L slots which hold the pins in place when locked. A practiced user can connect them quickly and they are not subject to cross-threading. Exercise 2. Here are the names of metal joint types missing from the text. Which passage refers to
Exercise 3. Answer the following questions about the text.
1. What are bolted joints? 2. What do bolted joints consist of? What are they secured with? 3. What are the two main types of bolted joint designs? 4. What do we usually apply to tight the bolt to the calculated clamp load? 5. What does the other type of bolted joint rely on? 6. What are splines? 7. Where is the smooth tip of the axle supported? 8. What is a bayonet connector? What does it consist of? 9. How does a bayonet mount connect the two parts? 10. What do you do to disconnect the two parts? Exercise 4. Complete the sentences with the information from the text.
1. Bolted joints consist of... that capture and join other parts, and are secured with the mating of …. 2. There are … main types of bolted joint designs. 3. In one method the bolt is tightened to …, usually by applying a measured torque load. 4. The other type of bolted joint does not have a designed clamp load but relies on …. 5. Splines are … or … on a drive shaft that mesh with grooves in a mating piece and transfer … to it, maintaining … between them. 6. An alternative to splines is a …, though splines provide a longer …. 7. A bayonet mount or bayonet connector is a … consisting of a male side with one or more …, and a female receptor with matching … and … to keep the two parts locked together. 8. To couple the two parts of …, the … on the male are aligned with the … on the female and the two pushed together. 9. The strength of the joint relies on … of the pins and … of the L slots which hold the pins in place when locked. Exercise 5. Re-read the text and determine if the following statements are: – true – false – of no information in the text.
1. Bolted joints are rarely used in construction and machine design. 2. In one design of bolted joints the bolt is tightened to a calculated clamp load, in the other it relies on the shear strength of the bolt shaft. 3. The bolted joint will be designed such that the clamp load is overcome by the forces acting on the joint. 4. Splines are ridges or teeth on a drive shaft that mesh with grooves in a mating piece and transfer torque to it. 5. Drive shafts on vehicles and power take-offs use splines to transmit torque and rotation and allow for changes in length. 6. A bayonet mount is a fastening mechanism consisting of a female side with one or more pins, and a male receptor with matching L slots and spring(s) to keep the two parts locked together. 7. The strength of the joint relies on the shear strength of the pins and the strength of the L slots which hold the pins in place when locked. Exercise 6. What class of joint do the joints described in the text above belong to? What other types of joints of this kind do you know? Can you list other possible classes of metal joints?
Exercise 7. Read the following text. What class of joint do the joints described in it belong to? Welding is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, with pressure sometimes used in conjunction with heat, or by itself, to produce the weld. Until the end of the 19th century, the only welding process was forge welding, which blacksmiths had used for centuries to join iron and steel by heating and hammering. Arc welding and oxyfuel welding were among the first processes to develop late in the century, and electric resistance welding followed soon after. Welding technology advanced quickly during the early 20th century as World War I and World War II drove the demand for reliable and inexpensive joining methods. Following the wars, several modern welding techniques were developed, including manual methods like shielded metal arc welding, now one of the most popular welding methods, as well as semi-automatic and automatic processes such as gas metal arc welding, submerged arc welding, flux-cored arc welding and electroslag welding. Developments continued with the invention of laser beam welding, electron beam welding, electromagnetic pulse welding and friction stir welding in the latter half of the century. Today, the science continues to advance. Robot welding is commonplace in industrial settings, and researchers continue to develop new welding methods and gain greater understanding of weld quality and properties. Soldering is a joining process in which two or more metal items are joined together by melting and flowing a filler metal (solder) into the joint, the filler metal having a lower melting point than the workpiece. Soldering differs from welding in that soldering does not involve melting the work pieces. There are three forms of soldering, each requiring progressively higher temperatures and producing an increasingly stronger joint strength: (1) soft soldering, which originally used a tin-lead alloy as the filler metal; (2) silver soldering, which uses an alloy containing silver; (3) brazing which uses a brass alloy for the filler. In the soldering process, heat is applied to the parts to be joined, causing the solder to melt and to bond to the workpieces in an alloying process called wetting. In stranded wire, the solder is drawn up into the wire by capillary action in a process called wicking. Capillary action also takes place when the workpieces are very close together or touching. The joint strength is dependent on the filler metal used, where soft solder is the weakest and the brass alloy used for brazing is the strongest. Soldering, which uses metal to join metal in a molecular bond has electrical conductivity and is water- and gas-tight. There is evidence that soldering was employed up to 5000 years ago in Mesopotamia. Exercise 8. Complete each Russian welding word of the puzzle with an appropriate English welding word. If you complete it correctly, the letters circled make another welding word. What is its Russian equivalent?
Exercise 9. Match the terms from the text to their Russian equivalents.
Exercise 10. Find in the text the English equivalents for the following Russian words and phrases. Процесс изготовления; вызывая слияние; добавление наполнителя; сформировать прочное соединение; в сочетании с; само по себе; в отличие от; создать соединение (связь) между; единственный сварочный процесс; нагреванием и ковкой; быстро развивалось; стимулировал спрос на; надежные и недорогие методы соединения; полуавтоматические и автоматические процессы; обычное явление в промышленных условиях; глубже понять; заливая припой в соединение; последовательно требующие все более высоких температур; производящие все более большую крепость соединений; сплав олова и свинца; сплав, содержащий серебро; медный сплав; скорректирован для изменения; части для соединения; в многожильном проводе; прочность соединения; электропроводность; водо- и газонепроницаемый.
Exercise 11. Find in the text the following English words and phrases and give their Russian equivalents. This is often done by; workpieces; a filler material; with pressure sometimes used; the only welding process; had used for centuries; the first processes to develop; late in the century; followed soon after; following the wars; developments continued with the invention of; in the latter half of the century; weld quality and properties; joined together by; having a lower melting point than; does not involve; originally; heat is applied to the parts to be joined; in stranded wire; drawn up into the wire; in a molecular bond; there is evidence; up to 5000 years ago. Exercise 12. Read the following text. What type of joint does the described fastener allow? What joint class does it, in its own turn, belong to? Summarize the text in Russian.
A rivet is a permanent mechanical fastener. Before being installed a rivet consists of a smooth cylindrical shaft with a head on one end. On installation the rivet is placed in a punched or pre-drilled hole, and the tail is upset, or bucked (i.e. deformed), so that it expands to about 1.5 times the original shaft diameter, holding the rivet in place. Because there is effectively a head on each end of an installed rivet, it can support tension loads (loads parallel to the axis of the shaft); however, it is much more capable of supporting shear loads (loads perpendicular to the axis of the shaft). Bolts and screws are better suited for tension applications. Fastenings used in traditional wooden boat building, like copper nails and clinch bolts, work on the same principle as the rivet but were in use long before the term rivet came about and, where they are remembered, are usually classified among the nails and bolts respectively. Before welding techniques and bolted joints were developed, metal framed buildings and structures such as the Eiffel Tower, Shukhov Tower and the Sydney Harbour Bridge were generally held together by riveting. Riveting is still widely used in applications where light weight and high strength are critical, such as in an aircraft. Many sheet-metal alloys are preferably not welded as deformation and modification of material properties can occur. Common but more exotic uses of rivets are to reinforce jeans and to produce the distinctive sound of a sizzle cymbal.
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