THE USE OF 3D PRINTERS IN CIVIL ENGINEERING INTRODUCTION The field of engineering has always relied on the use of models to represent ideas. Through these representations, engineers were able to visually demonstrate their new and innovative concepts. For years, engineers would have to hand-craft these replicas, a process which is very time and labor intensive. The use of 3D printing revolutionized how models and other engineering tools were made. With a few keystrokes and careful clicks, multiple copies of exact models could now be produced in a fraction of the time it would take someone to hand-craft the same model. Engineers began to realize that 3D printers can be utilized for more than simply creating prototypes; they saw they it was the key to unlock many other problems and difficulties in engineering. Recent developments in civil engineering have also revolutionized the field of affordable housing, as the use of 3D printers greatly diminishes the cost and resources needed to build a house. A Chinese engineering company recently constructed an entire home in less than 24 hours using only a 3D printer and recycled materials [1]. As an aspiring future civil engineer with a focus on structural engineering, 3D printing allows for innovative new designs that can be mass produced and implemented on a large scale.
3D PRINTING INFORMATION History 3D printing, also known as additive manufacturing (AM), is a process where three dimensional objects are created by laying down successive layers of material are laid down through computer controls. It was first developed by Chuck Hull in 1984 using a process known as stereolithography. This technique uses ultraviolet (UV) lasers to cut photopolymers. Hull also invented
the file format used in computers to create 3D printing. In 1986 Hull founded 3D Systems with the mindset of pushing this new technology into more commercial use. The biggest challenge for Hull achieving this goal was the fact that the lasers which gave the appropriate UV wavelength required substantial power centers and water cooling chambers [2]. This greatly limited the printer's market potential as it took up a large amount of space, time, and most importantly, money. As time and technology progressed, the option of solid state lasers became available; after wavelength compatibility issues became persistent, Hull made another calculated risk and reformulated materials to create the first Solid State Stereolithography System in 1996. This transition was a giant leap toward making 3D printers a household item. Ever since Hull produced the first 3D printer in 1984, the market for printing 3-dimensional objects has grown at an exponential rate. Once a luxurious commodity, 3D printers can now be found in many offices and business. Not only has the price of the printer itself decreased, but the cost of operating one has also gone down significantly, allowing this technology to be available to many businesses who previously wouldn't have been able to afford this machinery. Another reason why 3D printing is so popular is the fact that it leaves virtually no wasted materials and take away a company's need for international outsourcing [3]. Each day, more and more companies are realizing the benefits of 3D printing and are investing in this growing industry.
How 3D printers works The process of making a finished produced from a 3D printer is simpler than many would think. The whole procedure is just a few simple steps put together in a logical format. The first step is to create a 3D blueprint of the object you wish to produce using computer-aided design software; using a computer to create the blueprint allows for a level of exactness that cannot be matched by something that is handcrafted. Once the design is
ready, the printer must be prepared with the necessary materials needed to make the object. There are different technologies that can be used to create the object. Stereolithography, fused deposition modeling, laser sintering technology, selective laser modeling, and electronic beam melting are just some of the different techniques that can be used to make the finished product. While the process of creating an object is different for each technology, they all are programmed to do the same job in effective ways. Material extrusion, which is a process which combines many different technologies such as fused deposition modeling, is the most common process for desktop 3D printers. It works in a very interesting procedure. �Material extrusion works like a glue gun. The printing material -- typically a plastic filament -is heated until it liquefies and extruded through the print nozzle. Using information from the digital file -- the design is split into thin two-dimensional cross-sections so the printer knows exactly where to put material -- the nozzle deposits the polymer in thin layers, often 0.1 millimeter thick. The polymer solidifies quickly, bonding to the layer below before the build platform lowers and the print head adds another layer. � [4]
APPLICATION OF THE 3D PRINTER IN CIVIL ENGINEERING Creating models A major part of engineering is creating models to represent ideas and projects. Previously, engineers had to rely on hand crafted replicas which would take countless hours to construct and perfect. 3D printers have essentially caused this practice to become obsolete, as the printers can produce multiple copies of the design in a fraction of the time. In addition, the printers add a degree of precision that cannot be replicated by a human's touch; with the ability to mold an object to an infinite number of decimal points, any possible design specifications can be met perfectly.
The use of 3D printers makes for an overall more efficient engineering process. �3-D printing in industrial design saves a lot of time in the design process. Engineers can produce the prototypes themselves. The availability of prototypes ondemand via 3-D printing creates a testing process that would otherwise be drawn-out, difficult, and time-consuming.� [5] Any engineer can tell you the importance of time management when it comes to a design management, so the value of a 3D printer goes far beyond a simple monetary value.
Structural engineering Recent developments in the field of 3D printers have completely revolutionized the way civil engineering. Centuries ago, man relied on clay and mud to build simple shelters that were necessary for survival. Today, cranes and steel support beams are used to erect towering skyscrapers which serve as centers for trade and business. If one were to look at the development of construction techniques over the course of time, it would be hard not to be dumbfounded at the rate which the technology developed. Each decade seemed to bring a revolutionary new idea which transformed the way civil engineering was approached. The newest revolutionary idea is using 3D printers to build houses and increase the market for affordable housing. A company in China has successfully created an entire housing using only a 3D printer and recycled materials. Based out of Shanghai, WinSun Decoration Design Engineering Co used a massive 490 foot long, 33 foot wide, and 20 foot deep 3D printer to print cheap concrete made from recycled materials. The most amazing part of the process is that the entire house cost less than $5,000; capable of printing up to 10 houses in a single day, this engineering marvel could be the solution to the rising problem of an increase in the number of impoverished people in Chinese cities [6]. WinSun constructs its houses by printing out parts of the house pieces at a time and then assembling them on site. In
comparison, architects in Amsterdam are attempting to build a house where every detail will emerge fully formed. This project is projected to take at least three years to complete and will cost several million dollars to finance. At a current glance, it appears that WinSun's procedure is more efficient, but only time will tell which technique is more effective.
Relevance to my future I am currently aspiring to be a civil engineer with a focus on structural engineering, so this topic is incredibly interesting to me. I am looking forward to see how this field progresses as it currently seems to be an extremely innovative alternative to traditional construction practices. If 3D printing technology continues to improve and become more mainstream, I will certainly explore different ways in which I can utilize this amazing process. The entire 3D printing industry is already a promising enterprise, and has no signs that indicate it is slowing down any time soon.
CONCLUSION The use of 3D printers has completely revolutionized the way engineers approach problems and new ideas. Once limited to making drafts and crafting objects by hand, 3D printing allows engineers to utilize their time and resources extremely efficiently. It has created a new market for affordable housing and is becoming an instrumental part in new construction techniques. As the field of 3D printers becomes more mainstream and widely used across the engineering community, the technology used to design models will continue to improve until it is perfect for all engineering fields. 3D printing is without a technology of the future, as both engineers and businesses are already seeing the immediate benefits of investing in this field. By the time I enter the work force as a civil engineers, I am confident that 3D printers will be utilized by all engineering communities.
REFERENCES
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Hobson, James. (2014, April 16). �3D Printing Homes in Less Than 24 Hours Using Recycled Materials. � Hack A Day. (online article).http://hackaday.com/2014/04/26/3d-printinghomes-in-less-than-24-hours-using-recycled-materials/ N/A. (2013) �30 Years of Innovation.� 3D Systems. (online article). http://www.3dsystems.com/30-years-innovation Federico-O'Murchu, Linda. (2014, May 11). �How 3-D printing will radically change the world �. CNBC. (online article). http://www.cnbc.com/id/101638702#. N/A. (2014, June 19). �How 3D Printers Work �. Department of Energy. (online article). http://energy.gov/articles/how-3dprinters-work Scaggs, Caitlyn. (2013, October 30) �5 Industries Using 3D Printing Today.� Polymer Solutions. (online article). http://www.polymersolutions.com/blog/5-industries-using-3-dprinting-today/ Campbell-Dollaghan, Kelsey. (2014, April 3). �How a Chinese Company 3D-Printed Ten Houses In a Single Day. � Gizmodo. (online article). http://gizmodo.com/how-a-chinese-company3d-printed-ten-houses-in-a-single-1557613229
ADDITIONAL SOURCES Franco, Michael. (2014, March 14) �Giant 3D printer starts spitting out a house.� CNET. (online article). http://www.cnet.com/news/giant-3d-printer-starts-spitting-out-ahouse/ Wilcox, Kevin. (2012, August 14). �Printing Adds a New Dimension to Design. � ASCE�s Civil Engineering Magazine. (online article). http://www.asce.org/CEMagazine/Articlens.aspx? id=25769810812#.VCo8YPldVbL
ACKNOWLEDGEMENTS I would like to thank Dr. Radisav Vidic for providing me with the inspiration to choose the application of 3D printers in civil engineering as my topic for this research paper. I would also like
to thank Jake Arai, Chaz Donnely, Josh Lopez, and Coby Sartin for helping me revise, edit, and formulate new ideas for my paper.
