Commercial Software Packages and Computer Assisted Design - Assignment Example

SОLIDWОRKS АND САD Table of Contents Introduction 4 Commercial Software Packages 4 2D Drafting 4 2.5D CAD 5 3D CAD 6 3D Wireframe and Surface Modeling 7 Solid Modeling 8 3D Parametric Solid Modeling 8 3D Constructive Solid Geometry (CSG) 9 3D Hybrid Solid Modeling 10 3D Boundary Representation (Brep) 11 3D Feature-based Solid Modeling 12 3D Dynamic Solid Modelling 13 Advantages and Disadvantages of CAD Methods 14 Advantages 14 Disadvantages 15 CAD Hardware 15 Input devices 16 Mouse 16 Digitizers 16 Light Pens 16 Touch Sensitive Screens 17 Output Devices 17 Plotters and Printers 17 Finite Element Analysis (FEA) 18 FEA Procedure 18 Advantages and Disadvantages of FEA Methods 18 Advantages 18 Disadvantages 19 Conclusion 19 References 19 Introduction Computer Assisted Design or Computer Aided Design is a phenomenon in which there is a usage of several tools that are computer-based, which assist architects, engineers and design professionals. In the product lifecycle management process, CAD is the major geometry authoring tool. It is composed of software and hardware of special purpose. The latest software packages have 2D, which is about the drafting systems, and 3D, which is about solid design modellers and parametric surface [Gro83]. This word-processed report is composed of the generic 2D and 3D commercial software packages, the hardware that structures the CAD system and the Finite Element Analysis. Commercial Software Packages Commercial software packages are the one that are produced for a customer, who is liable to pay fee, by a commercial entity. The after purchase services, such as support, updates and training, are given to the customer by that commercial entity subsequently [Tak08]. Following are the generic commercial software packages types with their use in the mechanical engineering applications: 2D Drafting In two dimensional CAD, there are flat drawings of structures and products. The resultant objects from this CAD are created with the help of curves, ovals, circles, lines and slots. Such software packages are inclusive of the geometric image library, ability to offer the materials generation bills, ability to produce the Bezier splines, polylines and curves and the ability to describe the hatching patterns[Rab05]. The best software programs in this category are AutoCAD, CATIA v4, CADDS 5, Medusa and CADkey. Following is the example of 2D drafting: Figure 1: Example of 2D Drafting [Sma16] 2.5D CAD This generic type of commercial software is between the 2D and 3D CAD. The objects of this type are created with the help of geometric objects. The resultant objects are prismatic, because the depth of the objects is represented in this type superbly. Following is the example of 2.5D CAD: Figure 2: Example of 2.5D CAD [Sol15] 3D CAD There are a variety of programs that are developed in the three dimensional CAD. Such programs produce a realistic model in which the design object is up to the expectations of the designers, the production costs are lower and potential problems are solved early by the designers [Bos08]. Some of the 3D programs are Autodesk inventor, Solidworks, CoCreate Solid Designer, VX CAD, Unigraphcs NX and Pro/Engineer SolidEdge. Following is the illustration of the 3D CAD: Figure 3: Example of 3D CAD [Cad15] 3D Wireframe and Surface Modeling This generic type creates the inner-structure of an object that is skeleton-like. The outer surface is placed later on. Since, such programs are hard to translate into other software and this is the reason why they are rarely used by the designers. Following is the example of this generic type: Figure 4: Example of Wireframe and Surface Modeling [3dw12] Solid Modeling It is useful in the calculation of the object’s dimensions. It has six types, parametric modelling, Constructive Solid Geometry (CSG), hybrid, Boundary representation (Brep), feature-based and dynamic solid modelling [Jos88]. There all are described one by one in the following sections: 3D Parametric Solid Modeling Each entity, like a line, an arc, Boolean primitive or wireframe, is associated with some parameters in the 3D Parametric Solid Modeling. Several geometric properties and locations are controlled by these parameters. In order to have the desired part, the operator can change the parameters. The history-based method is used in this type of solid modeling to keep the record of the building process of the model. To create the new solid, the parameters are changed by the operator, due to which the operations are repeated from the history. To construct the relationship between the parameters, the constraint equations are added to the model. Below is the illustration of this generic type: Figure 5: Example of Parametric Solid Modeling [Scu15] 3D Constructive Solid Geometry (CSG) The 3D CSG programs are used to develop solid objects instead of the skeleton-like structures. For creating the objects, such programs uses the Boolean operations and solid primitives, like cones, cylinders and prisms. However, there is a lack of redimensioning and editing capabilities of software of this type. The model has to be reconstructed, if the designer wants to change something. Below is the example of CSG: Figure 6: Example of CSG [Gla09] 3D Hybrid Solid Modeling It is the combination of the CSG and Brep solid modeling to create the desired parts of the desired model. This is a most commercial solid modeling system that is used by the architects, engineers and other professionals. Following is an example of the Hybrid Solid Modeling: Figure 7: Example of the Hybrid Solid Modeling [Zw314] 3D Boundary Representation (Brep) A solid model is created in this generic 3D type by the wireframe profiles that are extruded, swept and revolved afterwards. Boolean operations are also used here. By combining the surfaces through the sewing operations, the solids are created. Below is the illustration of the Brep: Figure 8: Example of Brep [Wik15] 3D Feature-based Solid Modeling It is the preferred modeling method of the mechanical engineers in the world. It allows the modelers to perform the operations, like creating chamfers, fillets, pockets, holes and bosses that are linked up with certain faces and edges. Due to the regeneration, the faces or edges move with the feature operation in a way that the original relationships are maintained. However, if the features are not properly referenced, then it might not be placed in the right place at the time of regeneration. Following is the example of feature-based solid modeling: Figure 9: Example of Feature-based Solid Modeling [SAE13] 3D Dynamic Solid Modelling This type of solid modelling creates and refines the concepts to capture the ideas quickly for the designers. The process is fast due to the fact that during the encapsulating of ideas, the history is never considered. The major purpose of being the creation of those features that do not have the constraints of dimension. Below is an example of dynamic solid modeling: Figure 10: Example of Dynamic Solid Modeling [Des16] Advantages and Disadvantages of CAD Methods In this section, there will be a comparison of CAD methods with the manual methods in the context of advantages and disadvantages: Advantages CAD Methods Manual Methods Accuracy is maintained. The cost of equipment is low. All tools are electronic. The shapes, angels and sizes can be seen immediately during the construction. While viewing the drawing, the object can be seen in different sizes and resolutions. The record of dimensions is maintained. The editing process eases the way to move, rotate, copy, erase and mirror. The storage is done on a memory stick, hard drive, DVD or CD. It is easy to organize the drawing information into the overlays. The drawings can be obtained in seconds. Templates and libraries, record the data of the operator for the future use. It is easy to create the layout of the model. The resultant objects can be taken in colors with the element of high standard. The drawings can be linked to the machinery of Computer Numeric Control. Table 1: Advantages of CAD and Manual Methods Disadvantages CAD Methods Manual Methods Some shapes are hard to draw. For complex and large drawing, a big space is required. The purchase cost is higher. It cannot be connected to the devices of Computer Numeric Control. The replacement cost is higher. Storage facilities are required. The operators are required to update their skills after the release of a new CAD software. Much time is needed to draw manually. The designs are seldom accurate. The layout of the model is not created on a convenient basis. Table 2: Disadvantages of CAD and Manual Methods CAD Hardware Like the usual computers, CAD hardware is composed of CPU, memory, CD-ROM, monitor, keyboard, system unit, hard disk and printer. There are some additional devices that are included in the CAD hardware, which will be discussed in this section. The CAD hardware is divided into two categories, input devices and output devices [DeM94]. They are described as below with their functions and configuration in the industries. Input devices To provide the input, these devices connect to the computer for the communication purpose in the form of graphics and texts. Following are the hardware components that are included in the input devices: Mouse It contains numerous variable resistors that are able to send the signals to the PC. There are several functions of mouse, such as sketching, locating a point or place on a screen, accepting the commands, entering values and dragging the objects. The alternatives of mouse are joysticks and trackballs. Digitizers It is a free moving stylus or puck that is connected to a tablet. They are composed of electrical wires that are able to send and receive the signals between the computer and stylus. They are used to trace the sketch or make a 2D drawing by moving the cursor on the surface, which is flat. A feedback is provided to the computer, which is connected with the device, through the position of the cursor. Light Pens It looks like a pen that has a photocell to generate an electronic signal. When this pen is moved to the monitor screen, it quickly senses the light and that light is transformed into a signal. Lastly, the computer receives this signal in order to detect the exact placement of the pen on the screen of monitor. Touch Sensitive Screens It is located inside the monitor screens in the shape of overlays, mostly. The screen has the ability to sense the physical contact of the user. Output Devices These devices are required to view the object in the hard copies. Following are the output devices of CAD hardware: Plotters and Printers The plotters and printers are used to have the hard copy of the models. Plotters are used to view large images that are shaded or rendered. Printers can provide the 3D view in a comparatively small size. In typical industrial situation, the hardware is configured like the following way: Figure 11: Configuration of CAD Hardware in the Industries [UVI14] CAD workstations are used in the today’s society. Its cost is low. It can perform multiple tasks at a same time. The above process shows that there are two inputs and two outputs in a typical industrial situation configuration. Finite Element Analysis (FEA) The pre-processing of structures, its analysis and post-analysis is known as Finite Element Analysis. It is one of the components of the CAD packages. It predicts the way a product will react to the forces, e.g. heat, vibration, fluid, etc., of the real-world. It determines whether a product will work, wear out or break [Aut16]. FEA Procedure This analysis is composed of four major steps. They are: 1. Streamline an engineering problem into a problem that can be cracked by Finite Element Analysis. 2. Mesh the solid, define the properties of materials and apply the conditions of boundary. 3. Choose the functions that are appropriate, then formulate the linear equations and in the end, solve those equations. 4. Get, visualize and discuss the results. Advantages and Disadvantages of FEA Methods Advantages FEA Methods Manual Methods It can handle the complicated geometries and boundaries. It is easy to implement. It has a strong mathematical foundation. It is quick for simple geometries and boundaries. It has a better quality. It is widely used and applied. The element’s size can vary. Conditions of mixed boundaries can be handled. Impact on engineering curriculum. Table 3: Advantages of FEA and Manual Methods Disadvantages FEA Methods Manual Methods It does not generate the useful results and that leads to the production of pollution. It is difficult for such methods to solve the complicated problems. It gives solutions at nodal points only. The element’s size cannot vary. Conditions of mixed boundaries cannot be handled. Table 4: Disadvantages of FEA and Manual Methods Conclusion Computer Assisted Design or Computer Aided Design is a phenomenon in which there is a usage of several tools that are computer-based. The commercial software packages are either 2D or 3D. The advantages of CAD and FEA methods are more than their manual methods. The CAD hardware covers the input and output devices. FEA predicts the way a product will react to the forces, e.g. heat, vibration, fluid, etc., of the real-world. References Gro83: , (Groover & Zimmers, 1983), Tak08: , (Takei, et al., 2008), Rab05: , (Rabczuk & Belytschko, 2005), Sma16: , (Smarttcadd, 2016), Sol15: , (Solidcam, 2015), Bos08: , (Bosche & Haas, 2008), Cad15: , (Cadcam, 2015), 3dw12: , (3dwally, 2012), Jos88: , (Joshi & Chang, 1988), Scu15: , (Sculpteo, 2015), Gla09: , (Glasnost, 2009), Zw314: , (Zw3dna, 2014), Wik15: , (Wikipedia, 2015), SAE13: , (SAE International, 2013), Des16: , (Design Simulation, 2016), DeM94: , (De Micheli, 1994), UVI14: , (UVIC, 2014), Aut16: , (Autodesk, 2016; Courant, 1943), Read More