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smaller than the first-generation ones, besides this the speed also increased. For additional information, generation of computers basically depends on technology advancement rather than on the material. In the third generation, computers, integrated circuits (ICs) were introduced, which made them faster and were smaller in size. Fourth generations (today’s computers) are based on microprocessors, performance, and speeds of these computers are well known.
Now take another example of aircrafts. In aircraft structure design, material with high strength to weight ratio is a primary requirement. In the early days of the aircraft development, plywood and fabrics were used. These were the best available options at that time.Wrightflyeristhebestexampleofit,which was developed in 1903 by Wright brothers. With the advancement in the manufacturing technology, these materials were replaced with the stronger and lighter
aluminum alloys.
Further improvement came after the introduction of composite materials in the aerospace industry. Composite materials may have high strength to weight ratio when compared to metal alloys, so they are more suitable for aircraft application. Boeing’s 787 Dreamliner comprises nearly 50% carbon fiber reinforced plastic and other composite material which reduces the weight by about 20% as compared to aluminum design.
Today’s world is an era
of advanced materials. This is because the use of conventional materials has almost reached its saturation. Composites, FGMs, Aerogel, and Meta-materials, have become
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the game-changers. But every new material comes with its set of challenges. Analysis and manufacturing are two of them, because available studies or methods may not be suitable for these kinds of materials. For example, FGMs are non-homogeneous and generally isotropic while composites are non- homogeneous as well as anisotropic. The behaviour of these materials is very different from homogeneous-isotropic materials. These material exhibits non-classic effects, which are not observed in conventional materials (homogeneous-isotropic). This makes the analysis of these materials very complicated. The developed analysis methods are for conventional materials, hence inapplicable and unable to handle the complexity involved in the analysis. Manufacturing of these materials is also a big challenge, and available manufacturing techniques are not cost-effective.
We have already discussed that composites are non-homogenous and anisotropic in nature and shows non-classical effects. So what are these non-classical effects? To understand those, let’s take an example of a bar which is fixed at one end and free at the other. According to the classical mindset, when we pull this bar from free end, it will extend in the direction of the load, but it is not always true. It also can bend or twist, or both may occur simultaneously with extension of the bar. This coupling behaviour of bar deformation is called a non-
classical effect. Now we try to understand why this behaviour exhibits in non-homogenous and anisotropic materials only. To understand this,letustakeasimpleexampleofacantilever
Earlier, humans depended
on the materials which are naturally available. But these materials are not adequate for every application, so humans started to process them to get the desired property in it. In today’s world, a wide range of engineering materials are available, such as metals and its alloys, polymers, ceramics and composites.