As a mechanical engineer, there is a lot of computer software you use model designs, run simulations and analyse results. But there are some that are more important to grasp than others and it is essential you are familiar with them. The following summaries describe some of these software packages with examples of how and why you will use them.
Computer Aided Design (CAD) Software
First of all CAD is at the forefront of engineering, there’s no escaping it. Whether this is CATIA, SolidWorks, AutoCAD or another package, it is simply unavoidable especially mechanical engineering. CAD can be used to build 3D models of parts and assemblies allowing parts to be designed to fit together, checking for clashes. CAD packages also allow 2D drafting which is important for every mechanical engineer to learn regardless of whether or not it may be becoming outdated.
One mistake I made at university was not doing enough CAD work! My advice for any students out there, take full advantage of the software you have access too! Many software packages are available as student editions which are often free or available at a reduced price. CATIA is arguably the most commonly used in industry but experience using any CAD package is valuable. It involves thinking about how parts can be constructed from first principles using simple geometry and features to create complex shapes.
CAD is used throughout product life cycles, from its initial design through to manufacturing and assembly analysis. It offers lower product development costs since fewer physical prototype parts need to be made and increased productivity. Measurements are also easier and more accurate in CAD than on physical parts.
Source: Car Body Design
For further reading follow these links to our previous blogs where we discuss which CAD software should your business invest in, the future of CAD, CAD outsourcing and whether it’s worth obtaining a CAD certificate to increase your chances of getting a job in industry.
MATLAB (Matrix Laboratory)
Computer Aided Engineering (CAE)
Although used more commonly in civil engineering, CAE is also used to perform simulations such as crash testing on vehicles and stress analysis on components. CAE is a collective term for different processes including Computational Fluid Dynamics (CFD), Multi Body Dynamics (MBD) and Finite Element Analysis (FEA). These processes simulate how a model will perform under certain conditions (stresses present in the material and deflections produced under load). Popular software includes Star CCM+ (CFD), ANSYS and RecurDyn.
CAE involves pre-processing (modelling), solving (applying the laws of physics to mathematically compute a the result of a simulation under certain conditions) and post-processing (presenting the result). Finite Element Methods are widely used in CAE to solve engineering problems and predict the behaviour of components before they are produced so designs can be improved if necessary. Using FEM in design evaluation allows increased design efficiency and effectiveness, simplification of the design process and economy of material and labour allowing companies to save money, as they do not need to manufacture parts to test them but rather simulate the operating conditions through using computer software and minimise the amount of material used in the parts. Care must be taken in finite element analysis however as designs can be produced that are very difficult to manufacture.
CFD is a branch of fluid mechanics that uses numerical analysis to solve problems involves fluids (liquids or gases). By defining boundary conditions, analysis techniques such as finite difference method are used to generate solutions to the Navier-Stokes equations and perform simulations. The speed and accuracy of these solutions increases with computing power. CFD simulations can be validated with wind tunnel testing.
This screenshot from Star CCM+ shows the velocity flow vectors around a cross section of a Formula 1 cars front wing. Similar illustrations can be used to show areas of high and low pressure as well as boundary layers in CFD.
Although Excel can be used for quick calculations, tabulating data, drawing shapes, it can be very powerful as it has the ability to run macros and update charts automatically from input data. Functions such as ‘index’ and ‘match’ can perform linear interpolation on a set of data and equations can also be fitted to data using the ‘linest’ function. Regression analysis can also be useful in statistics.
Excel is a very versatile piece of software that has a range of applications. As a mechanical engineer, there’s not a day that goes by without me using it, even if it’s just to perform simple tasks like calculations or recording data. It can make long and repetitive jobs much simpler and quicker, like MATLAB. Using macros can save you a lot of time too and they can be used to automatically perform a series of commands you regularly use at just the click of a button.
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