M. Ibbotson - Professional english in use engineering (794233), страница 3
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drawing, andI have therefore told the fabrication team not to (8) ................................ to it until wereceive clarification.Ove-r .f-o tjotc~Think about design development on a project you have worked on, or on a type of projectyou know about. Describe the key stages from the design brief to the issue and ongoingrevision of working drawings. Say how designers, consultants and production teams areinvolved at each stage of the process, and explain what procedures are used.Professional English in Use EngineeringIIDesign solutionsDesign objectivesThe web page below is from a manufacturing company's intranet.Company design procedure- the design briefA design brief for the proposed product should be drawn up by theproject engineer.
This should consist of a detailed list of technicalobjectives which the design team must work to, in order to produce adesign solution .Key elements of the brief are:•function - the product's intended use (what it is designed to do),including performance targets (strength, power, durability, etc.)•constraints - limits on the design (for example, it must not exceed amaximum size or weight limit)•comparative targets- how well the product should perform, comparedwith existing models (competing products already on the market. orthe current model that the new product will replace)•design features - specific things the new design must have (forexample, rechargeable batteries, or a lid with a lock)ebudget - the cost limits that must not be exceeded, in order to makethe design cost-effective.- - Design calculationsDesign information is shown on drawings, and written in specifications - documents whichdescribe the materials, sizes and technical requirements of components.
In order to specifythis detailed information, an engineer must evaluate- that is, identify and calculate- theloads (forces) that key components will have to carry. To do this, the engineer needs todetermine (identify) the different loads, then quantify them- that is, calculate them innumber form. Usually, each load is quantified based on a worst-case scenario- in otherwords, the engineer will allow for the maximum load, such as an aircraft making a very hardlanding, or a bridge being hit by extremely high winds.After maximum loads have been quantified, an engineer will apply a factor of safety.
This isan extra margin to make the component strong enough to carry loads that are higher thanthe worst-case scenario. For example, a factor of 1.5 increases the load a component cancarry by 50%. After this has been factored in, the engineer will then size the componentsthat is, calculate their required size.Engineers are sometimes criticized because they overdesign things (add excessive factors ofsafety), which increases costs. However, according to Murphy's Law, 'Anything that can gowrong, will.' This suggests that belt and braces- an expression often used in engineering,based on the safest method of holding up trousers - is a sensible approach.12Professional English in Use Engineering3.1Complete the sentences from technical con versations using the words in the box. Look at Aopposite to help you.budgetconstraintcost-effectivedesignedexceedexistingfeaturefunctionproposed!Ju-tOf Cou(se.., mone'j i.s limi-ted. C..O.s-t limi-taiion.s ace alwa'j.s a ................................A ................................
has been a lloca-ted fQ( -the pceliminac'jof •:.?,000. !Ju-t we mu.s-tn '- t ................................ Tha-t amoun-t.some fina nce i.s available .de.sign phase. -2a -to-talObviou.sl'j, if we have -to spend €BO on componen-ts fQ( each appliance, and-the appliances ace .sold fo( €70, -tha.-t '.s no-t a ................................ des ign .soluTion.3lhe ................................ of fui.s de-tec-to( Is -to loca-te unde(g( O<Jnd cable.sb<jgiving audiofeedback. . Since i-t '.s ................................ -to be use..d in noiS<j envi(onmen-t.s, -the ea(phone isan impoc-tan-t ................................ .4A(e -these.
al(ead'j on -the mack.e-t ace3.2weace -t'ne<j ................................ produc-ts? Or-talk.ing abou-t ................................ pcoduc-t.s Tha-t ace .siill under developmen-t?Choose the correct words from the brackets to complete the sentences.
Look at B opposite tohelp you.1 The types of loads that will be encountered must be (designed I determined).2 Maximum loads are based on predicted (specifications I worst-case scenarios).3 On top of maximum loads, additional safety margins are (factored in I sized).4 For cost reasons, components shouldn 't be (overdesigned I quantified) .5 The practice of overdesigning components can be described as the (belt and braces I factorof safety) approach.6 (Quantifying I Sizing ) components means calculating their dimensions.3.3Replace the underlined words and expressions with alternative words and expressions fromA and B opposite.Most engineeri ng designs ( I) make provision for excessive or abnormal operatingcond it ions.The critical question is, how much of a (2) percentage of extra size or capacityshould be applied without (3) adding too much of a margin? To (4) calculate an amountfo r this figure , it is critical to assess the consequences of a technical failure.Wherethe stakes are high, in applications such as aviation, designing for (5) the most extremesituations is clearly critical on safety grounds.
On the face of it, the result of this may seemcostly. But where the human implications and expense of failure are serious, a high level ofexpenditure aimed at accident prevention can be considered (6) financially viable.Ov~r 1-o tjoufJ1Think about overdesi9n in a field of mgincering you are familiar with. How easy or diffirultis it to predict and quantify loads? How serious are the eonscqut' lllTS (human ami financial)of terhniral failures? As a result, how high are typiral fal'lors of s<lfl'ly?Professional English in Use Engineering13Horizontal and vertical measurements-Linear dimensionsThe web page shows the key dimensions of the Airbus A380 in metres, and the explanationsbelow it describe how they are measured.
In the explanations, the word plane means animaginary surface (not an aeroplane). On drawings, planes are shown as lines that indicatewhere dimensions are measured from and to, and are positioned to strike (touch) the faces(edges or surfaces) of components. Often, they are either horizontal planes or vertical planes.Airbus A380 dimensions:EC'),.....r:c;,c:.S1Wingspan 79.Bm~Q)H Maximumi ! fuselage width>0[J7.14m~'' ''Maximum cabin width 6.58mOverall length is a measurement of how long the aircraft is in total.
The measurement is takenbetween the two points that are furthest apart (the front and rear extremities), along the lengthof the aircraft. The length is measured along a horizontal plane. It is the distance between avertical plane striking the front of the nose, and a vertical plane striking the rear of the tail.Wingspan is the total distance spanned by both wings . The span is measured as a straight linebetween the two wingtips.Overall height measures how tall the aircraft is. The dimension is measured vertically betweenthe underside of the wheels and a horizontal plane striking the top of the tail.Maximum fuselage width is the external width of the aircraft's body- how wide it is,measured horizontally between vertical planes striking the outside faces of the fuselage.Maximum cabin width states the maximum internal width, measured between the inside facesof the fuselage.
The measurement is equivalent to the external width , less the thickness of thefuselage at each side of the aircraft.Notes: When written, the words dimension and dimensions are often abbreviated to dim and dims.Span is also used to describe the distance(s) crossed by a bridge, between its supports. If abridge has a support at its centre (as well as at each end), then it has two spans.-level and plumbIf a surface is described as being level, this means it is both horizontal and flat (smooth).However, a surface which is flat is not necessarily horizontal.
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