Engineering drawing is the best way to express engineering concepts and exchange information. If any component is to be specified, the following information is needed:
- All the dimensions of the component
- Description of the material to be used
- Parameters like weight, tensile strength, ductility, etc.
CAD is now a given for designing of any machine part, equipment or system for the advantages it brings over conventional drafting. CAD helps designers and engineers create ideas, make visualizations and produce precise drawings. Indeed, having training in CAD gives design engineers an edge in their career pursuit.
Visualization of the object to be created is one of the most powerful means of communication. CAD reduces the drawing time and more importantly, eliminates personal skill dependency. Manual drawings were mostly orthogonal; today’s CAD software allows creation of 3D objects with ease. CAD presents a few distinct viewing advantages:
- Creation of sectional view
- Creation of an image that does not require the end user to have special software for viewing
iii. Multiple copies can be made and transmitted easily without loss of accuracy
Mechanism design can be divided into two types, kinematic design and dynamic design. CAD systems allow designers to create a 3D model of each of the components to create either a kinematic or dynamic mechanism. Kinematic design allows a designer to animate the CAD model. Dynamic design allows engineers to optimize the various properties of the mechanism.
Finite Element Analysis
Finite Element Analysis is the process of solving the matrix of equations and determination of unknown variables like displacement, etc. at various nodes. It is a time consuming task, especially for objects with a complex geometry.
CAD software enables a user to analyze the model under different loading conditions with excellent visualization aids.
CAD provides a distinctive advantage in manufacturing. The most used areas of CAM in manufacturing are:
- Manufacturing through CNC machines
- Computerized measuring or inspection
iii. Computerized robotics application
CAD software often provides an integrated module to generate a tool path and associated codes for the respective machines.
This is one of the advanced modules in CAD, customized for sheet metal and press work. Sheet metal modules have various sets of handy tools that can be used to create most used sheet metal features, increasing user-friendliness and reducing the time to create the sheet metal model.
CAD or CAE software also allows simulation of plastic or metal flow. Metal castings can be created by adding gates, runners, risers, etc. In case of plastic moulding, the final models are created first and the part is placed inside the work piece from which the core and cavities are extracted.
One of the most use of CAD is in animation. Animation is used for presentation and understanding of component functions or processes. Mechanisms can also be animated using special CAD modules. Since most of the mechanisms have more than one moving parts, it is difficult to visualize their relative motion. Animated CAD simulation shows the behaviour of all the components in a mechanism, helping engineers understand the mechanism better.
In most engineering products, there are many rules that are standardized. A designer needs to carry out calculations for every new component. If the rules are imposed on the CAD model itself, by keeping the real variables open to variation and all related dimensions, automation becomes very easy. Since even small automation reduces work load CAD increases productivity.
CAD provides automatic evolution of and adjustment in a different pattern so that the material utilization can be increased. This is very useful when several components are to be cut from a single sheet, or components of various shapes are to be cut from the same material.
In an environment where various users are connected to the same CAD software, collaboration becomes very easy. This is particularly useful in case of large component development where engineers of several disciplines work on a single project, and their components are related to each other.