7.4 The impact of technology on society Engineering is apparently driven by the needs of society. The technology that results, in turn, drives other changes in our everyday lives. One of the basic needs identified in Section 2 was for shelter. There are many fine examples of long-surviving structures such as pyramids, aqueducts, bridges, walls, functional buildings, and so on. Remarkably these constructions were completed without the depth of analysis and understanding that is available today (though we don't necessarily know much
6 A problem with sensors The problem we will look at in this section concerns the analysis of the design of a component used in cars that are fitted with airbags. The airbag has to be inflated rapidly when an electronic circuit in the system decides that a serious collision is taking place. The crucial component in the electronics is the accelerometer, which therefore has to be extremely reliable. Motor manufacturers have turned to a technology called MEMS (micro-electromechanical systems) for these accelerometers, b
4.6 Assess and review Following our problem-solving map, we have reached the stage of 'assess and review solution', Figure 16. 4.5.2 Physical models A physical model of an artefact or component is often built on a reduced scale, in size and/or by using materials that are cheaper and easier to manipulate than those intended for production. At this stage, we are not necessarily producing what you might think of as a prototype, but investigating particular aspects of the design. For instance, maybe we would produce a racing-bike frame to a new design but in a cheap material such as balsawood, in order to assess the air flow around it in a wi 4.5.1 Mathematical models Computers in the last few decades have, in many cases, made mathematical modelling a lot easier. Models that used to require hours of manual cranking through long equations can now be created on a screen using specialist software. Processes can be recreated – modelled – in the time it takes to press a few buttons. For example, when designing a pipe network to carry a gas or fluid, such as in the village water supply problem, you might wish to know how the flow would be distributed w 4.5 Model the best solution In moving from the 'possible solutions' to the 'best solution' box, Figure 12, we have to assume that a certain amount of evaluation has been done in the previous loop. The solution is still on paper, and probably not much more than a sketch, but something is badly wrong if the best solution to come forward has n 4.4.1 Selecting the best candidate Assuming there is more than one likely looking candidate solution, we need to make a selection now so that we don't waste time taking all the candidates through the next steps, which become progressively more expensive and time-consuming. The rigour and formality of this step is very variable, but in general all schemes boil down to the same process you might use to choose some consumer item, such as a TV set. You would have a list of criteria that are important to you, and you would evaluate 4.2 From a need to a problem So, working from the top down, the process starts with 'need' and 'problem'; see Figure 8. Although we usually work by identifying a need that converts to a problem, that requires a solution, don't forget the extra arrow at the side, taking this first part of the process full circle. The questions that draw 4.1 Advancing knowledge Over the centuries, engineers have faced and solved a huge number of problems of one sort or another. Each time a problem is solved, knowledge is advanced, something usually gets written down, and so today we have a wealth of experience to draw on. Equally, problem-solving techniques have also been developed and evolved through use and refinement, which is rather handy. Not only do we have some idea of existing solutions to similar problems, but we also have an indication of how to go 2 Where does the need arise? There is a rather obvious question that has to be raised at some point, so we may as well get it over with now: Why do we present ourselves with all these problems? After all, life would be easier without them and we could all go off and do jobs that don't involve them. Do we really need to know everything about the universe? Or to send people into space, at significant cost and human risk? Do we really need to send sound and pictures through space? Do we really need to communicate with peopl 1.3 Innovation by development Innovation by development is about changing the bit that doesn't work, or that could work better, to improve the function of the whole for reasons of cost, performance, ease of manufacture or competitive edge. You probably noticed in Box 1 'Innovation by context – an example' that Baylis had to incorporate a nu 1.2 Innovation by context The word 'innovate' simply means 'make new'. We have chosen in this course to narrow the meaning of this term to be more or less synonymous with 'invention'. I would argue that innovation by context is as much a process as a result. By that, I'm using the term to mean something more like 'creativity'; and it's creativity that lies at the heart of all engineering. More than anything else in our professional lives, we engineers are excited by the prospect of being responsible for the creation o Acknowledgements Except for third party materials and otherwise stated (see terms and conditions), this content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence Grateful acknowledgement is made to the following for permission to reproduce material: References Keep on learning   There are more than 800 courses on OpenLearn for you to Conclusion This free course provided an introduction to studying Engineering. It took you through a series of exercises designed to develop your approach to study and learning at a distance, and helped to improve your confidence as an independent learner. 5.7 Fitment flaws The secondary category of defects observed by Law and his team refer to defects of fitment of the columns and braces together during construction of the bridge. He noted many bolt holes had been deliberately enlarged, but why this was necessary remains unclear, especially as the bolts were 0.125 inch smaller than the holes. Perhaps burrs or points in the holes needed removal before the bolts would fit correctly. The quadrants also came in for criticism for their poor fit to the columns, and i 5.6 Casting defects The first class of defect would have been inferred from examination of fractures in the cast-iron columns, where, for example, the wall thickness would be exposed for measurement. However, some of the casting defects he mentioned in his testimony – and which were to gain some notoriety both in the popular press accounts of the enquiry and in later accounts – are difficult to describe in detail because he did not specify where they were found in the debris, or how exactly they had contribu 4.9 Survey results We have inspected some of the remains of the collapsed bridge using the set of photographs taken shortly after the disaster for the official inquiry. It is important to emphasise that the pictures form only a small part of the total of fifty, but those chosen were selected to give the clearest evidence of the failure modes in the cast-iron piers that supported the high girders. They are by the far the best real evidence to rely on to understand how and why the structure failed. It would 4.8 Photographs showing the detail: standing pier 28 The final part of the survey deals with the two standing piers connected to the lower girders left after the high girders section fell during the disaster. The whole of pier 28 is shown in Figure 34, and two close-ups of the columns are shown in Figures Author(s):
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