Computer-Aided Design And Manufacturing Applications
Introduction
Computer-Aided Design (CAD) is defined as the use of computer systems to assist the creation, modification, analysis, or optimization of a design. In the past when first introduced, CAD was not a viable option for use in industries as machines back then were very costly. However, with the improvement in technology, computers now have better processing power, thus allowing users to provide a better representation of the dimensions and the properties of the object.
The use of CAD came about from three needs:
- Attempts to automate drafting process, as computer modelling allowed for easier corrections/manipulations just by changing a model’s parameters;
- It provided a way of testing designs by simulation;
- It helped to facilitate the flow from the design process to the manufacturing process using numeric control technologies. The gradual adoption of CAD in industries shortened the period of time between design and manufacture, as well as expanding the scope of production process, thus creating the possibility of integrating both the design and manufacturing process.
In today’s world, CAD softwares are being used in various industries. Typically, CAD modelling is used in many engineering applications. Chemical Engineers use them for process design and analysis to ensure optimal plant operation; Civil Engineers, who design and construct public and private works, use CAD to ensure that their designs are safe for public; Electrical Engineers use them to create electrical and electronic diagrams; Mechanical Engineers use CAD modelling to assist with their design and simulation of actual applications of their designs.
While the above lists some of the conventional uses of CAD modelling, CAD modelling has its uses in other industries as well. Due to CAD being able to easily design 2D and 3D diagrams, it is currently being adopted by various industries to provide easy visualization of how an item looks like in 3D. Some of the unconventional use of CAD modelling would be in the Fashion Industry, Medicine, Augmented Reality (AR), etc. In this report, we will examine how CAD has been integrated for use in some of these industries, the benefits it brings to the industry, as well as the short-comings CAD has that is unable to help solve certain problems.
CAD in the Fashion Industry
Fashion refers to the popular style of any time period, with respect to the way people dress and present themselves. Back in the 19th Century when modern fashion began to develop, designers created their works by designing using a pencil and paper. However, in today’s fast-paced society, fashion trends are changing very quickly, leaving fashion designers have a very short lead time to come up with designs for the next cycle of fashion products. Although designers now still use a pencil and paper to come up with their designs, CAD modelling is becoming more favoured as the mode of designing due to the various advantages it provides to designers. Firstly, CAD modelling is a cost-saving method for designers. Due to the rapid changes in fashion trends, as well as the company’s own needs to reduce cost, there is a pressure from the retail sector to shorten product-development as much as possible. CAD modelling provides an alternative to designers when it comes to physical prototyping. Before CAD modelling, designers had to commission a physical prototype in order to see how their product would look like. However, more often than not, the physical prototype turned out differently from what the designers imagined them to be, be it due to colour, material type, or other reasons. As such, the designers had to keep sending modified designs in for prototyping. The cycle of repeated prototyping is one of the reasons for high cost in the development of the clothing. With CAD modelling, the designer will be able to see their design immediately without the need for prototyping, thus reducing much of the prototyping cost from the developmental stage.
Secondly, the speed that CAD modelling provides. With the CAD modelling software, designers can create new sketches more quickly and more precisely without having to redo their drawings by erasing. CAD modelling’s ease of use also allows designers to test out their creativity quickly, allowing them to visualize their new designs in a 3D environment, thus allowing designers to modify and create new garments quickly. In addition to the drafting, CAD modelling allows designers to cut down on lead time, simply by allowing them to visualize the product without the need of an actual prototype. In today’s world, most clothing retailers have adopted offshore sourcing and production strategies, thus locating their clothing production to countries with lower labour cost. When it comes to physical prototyping, not only do we have to take into account the time needed to produce the prototype, we have to take into account the time required to transport the prototype to the designer. Based on traditional clothing production, 2 to 10 prototypes are required before putting the actual product in the market. This is responsible for most of the lead time in the cycle of garment production. The ability to visualize a product in 3D allows the designer to know how their product will turn out without the need of an actual prototype, thus cutting down the lead time to just the production of a final prototype to confirm the design.
Although there are benefits to using CAD modelling with regards to the fashion industry, there are some problems that CAD modelling is unable to solve. The most important factor is that it provides only a virtual environment. There is so much a programmer is able to program into the CAD software with regards to the material property. Thus, even though CAD modelling allows the designer to see how the final product looks like, it may not accurately depict the final product as the actual material property would affect how the final product will turn out as well
.In addition, perhaps due to CAD modelling still being relatively new to the fashion industry compared to the traditional pen and paper method, designers are still hesitant to try to fit their designs onto 3D avatars to test out its looks. As reported by Porterfield and Lamar, some of their research participants were hesitant in making fit decisions just based on a virtual avatar, as the participants were used to relying on their physical proximity to the fit model to establish fit. Moreover, there is a learning curve in the transit from the traditional pen and paper method to CAD modelling, thus in the short-term, may not be able to reduce the lead time of the developmental period.
CAD in Medical Usage
When it comes to medicine, most people think of CAD as being able to easily design prostheses for those who require it. However, CAD can be used to fit other areas of medicine as well. One such example would be for surgery. Due to difference in the physiques of different people, it can be difficult for doctors to prescribe the same treatment to different people even though conditions may be similar. Approaches to surgeries for different people are to the extent that only the basics are different. This is because differences in each person’s physique plays an important role in customizing the treatment for different individuals. Due to the difference, doctors will need different approaches towards the surgery for the different individuals. CAD modelling provides several benefits to the medical industry. Firstly, as mentioned before, CAD modelling is able to benefit surgeries. Traditionally, surgical planning has been used on just bone manipulation, due to modelling software in the past being unable to depict soft materials like cloth or skin. With the introduction of CAD modelling for surgery usage, it is now possible for surgeons to better tailor the method of treatment for different patients. CAD modelling has enabled surgeons to construct a virtual condition of the patient’s body structure. By doing so, the surgeon can make a more detailed analysis of the patient’s condition and administer the appropriate treatment. This can be done by converting the raw CT scan data to structure triangulation language format for digital modelling purposes. Moreover, with the virtual environment, the surgeon is able to plan for the surgery, such as planning for the steps during the surgery, virtual surgery, design of any needed implants, and the post-surgery effects simulation. With the CAD model, the surgeon is able to test out different methods and strategies on how to proceed with the operation. The virtual environment will alert the surgeon to some unanticipated problems that could occur during the operation, thus improving the chances of a successful operation.
The next application of CAD in the medical industry would be organ regeneration. When it comes to this sector of medicine, CAD could play a very important role in saving lives. From the U.S. Department of Health and Services, as of August 2017, more than 100,000 people are on the organ transplant waiting list, and that 20 people die each day while waiting for a transplant. In comparison, there is a shortage of organ donors, and very few of them die in a way that allows their organs to be transplanted. The organ shortage is a serious problem. However, the use of CAD can be a way to help mitigate some of the reliance on organ donors. 3D printing of organs requires:
- A blueprint model containing bio-information, physical and material information;
- A process model detailing how the model should be built;
- A process machine;
- A suitable culture system to grow the cells.
Out of the 4 steps, the CAD software is responsible for three of it. The CAD software can be used to build the model of the organ, along with specification of the biomaterials needed to build it. This can be easily generated based on medical imaging data. Moreover, for the printing of the organ to occur, the toolpath of the process machine has to know where to go in order to deposit the cell. Due to the complexity of a human organ, which contains not just the type of cells needed for the organ to work, but also cells such as nerves and blood vessels, the database containing all these information can be very complex. In most cases, such information can only be processed by a CAD software. This ability of CAD software satisfies the second and third requirements of 3D printing of organs. Due to CAD being able to process all these information in order to build a working organ, CAD is becoming increasingly important to the medical industry in the sector of organ transplant, where a shortage of organs is present.
Despite these benefits, there are some limitations as to how much CAD can currently contribute to Medicine. Firstly, with regards to surgery, if CAD is used, more time will be spent in the preparation of the operation. However, in certain surgeries, such as tumours, which continue to develop as time passes, it is necessary for the doctor to remove it within a maximum of three weeks. Moreover, due to the growing of tumours, it will be impossible for doctors to have a fixed model to work on as the tumour may develop differently from the simulation. This would end up increasing the risk of the operation. In addition, similar to what was mentioned for the fashion industry, time is needed to train experts on the usage of CAD softwares for application in the medical industry. This transition would require time for people to get used to, and training would be required to improve the skills of these people. On top of that, the simulation, while able to allow doctors to pick the right method of treatment for the patient, it is not an alternative to actual practice. This practice comes with experience, and CAD is only able to help the doctors with reducing the level of risk associated with the treatment. However, this limitation could be reduced if CAD is used in other areas which could help assist medicine, for example, virtual or augmented reality, which would give doctors an extra edge, and these technologies could be done with CAD as well.
Conclusion
In conclusion, CAD modelling is not only applicable to conventional means of usage such as designing of products in the engineering field, it has its own benefits to the various industries where people do expect CAD to be useful in. However, as CAD modelling in these industries are still relatively new compared to the engineering industry, some of these softwares may not have fully permeated the industry yet. Thus, there is a need to train up professionals who would one day use these programmes. In addition, some of these softwares are still in the developmental phase. Although some papers mentioned that their research participants are willing to do a switch to CAD modelling, especially with reference to the fashion industry, some are hesitant to do so due to the features not being able to satisfy what they require for their design. Moreover, there is a need to train these people in the use of CAD modelling in order to integrate the use of CAD into these industries. The time needed to train these people and for them to get familiarized with the system may cause a temporary drop in the efficiency of these industries. In addition, with reference to the medical industry, CAD software has to be used in conjunction with other technologies in order to have the best possible effect. If the technology that CAD has to be used with is not fully developed, the effectiveness of CAD would be limited greatly, thus hindering its effectiveness on solving present issues. However, with the future improvements to CAD software, as well as trainings for the people in the relevant industries, unconventional applications of CAD will one day be an integral part of life.
