Here at Pretty Brainy, our goal is to empower girls to gain experience in STEAM: science, technology, engineering, art, and math. Computer-aided design, or CAD, blends all of these disciplines and utilizes technology to bring ideas to life.
By Katie Schutt
CAD is the use of computer software to plan, create, or analyze a design. From architecture to animation to automobiles, countless industries utilize CAD as a tool to visualize ideas before converting them into physical objects or final products. If you have a brilliant idea for a product or a part, say, an upright suspension for a racecar (the part that connects the tire to the steering components of a vehicle), how do you know what it will look like?
Ioana Dumitru is a Mechanical Engineering student who designs and manufactures car parts for the Formula Racing Team at the University of Colorado Boulder. Using the CAD software SolidWorks, she modeled the front upright suspension that was manufactured and used in a car that competed in road races against other colleges.
“I remember working on this part every week for about a year, and during this time I had to scratch the design and completely start over,” says Ioana. As her design changed to ensure structural support and fit with the shapes and sizes of the other car parts, using a computer allowed her to easily and quickly edit important details of the model like its dimensions.
The automotive industry isn’t the only one that relies on CAD to design products. For instance, Samantha Preston is a mechanical design engineer at the company Medtronic which utilizes software like SolidWorks and PTC Creo to create medical devices like pacemakers, insulin pumps, and surgical tools.
“It requires a lot of research, brainstorming, and creative thinking,” explains Samantha. This is true at every step in her engineering design process, beginning with understanding the surgical navigation tools that already exist in order to have a good foundation for her ideas for improvements or totally new tools. To transition from idea to product, she starts by sketching her design on paper to visualize its sizing and general appearance. Then, she creates her design as a 3D model in CAD where she is able to include extremely complex detail. As she brainstorms how customers will use her surgical tools and how the tools might fail during use, those complex details can quickly be adjusted.
CAD is not just limited to creating a design! After modeling something in a virtual environment, CAD software can be used to test and predict how parts will work when physically created and interacting with other parts.
When Ioana was designing the upright suspension for the racecar, she also used Finite Element Analysis (FEA) within the CAD software to simulate and predict how the part would react to real-world forces. According to Autodesk, a corporation that makes CAD software, “Finite Element Analysis shows whether a product will break, wear out, or work the way it was designed.“
“Because this part was so structurally important, I had to run a Finite Element Analysis to simulate the forces on it in cases of high braking and cornering (turning),” says Ioana. The process is called Finite Element Analysis because the computer software split her upright suspension into millions of small pieces, ran calculations on each piece to see how it would react to the simulated forces, and then added up those results to see how the whole upright suspension would perform. Even before making and testing a physical upright suspension in the racecar, the results of this analysis were able inform Ioana how she might change her design to perform better under the forces it would experience.
Computer-aided design also allows an engineer to build an assembly that consists of multiple different parts. This is exactly what Autumn Zemlicka is doing as the CAD Engineer on her senior design project for Ball Packaging, the company that manufactures aluminum cans for soda and glass jars for canning. Her senior design team has put together an assembly in SolidWorks that models a machine that automatically cleans itself!
“In manufacturing beverage cans, a coating is applied to the interior surface,” Autumn explains. “As the coating shoots into the cans, there is a significant amount of blowback. Spray that did not adhere to the can rebounds, which causes buildup on and around the machine that may result in improperly coated cans and defective products. Our goal is to design a device to automatically clean off any buildup from the machine.”
Her design consists of hundreds of parts ranging from air nozzles to the motors that move them and the screws that fasten them. Bringing these components together in an assembly allows Autumn to see how they will all fit together and if she needs to modify her designs in order for the components to do so. Within the assembly she can also simulate how the parts of the machine will move together as they coat the beverage cans and then clean themselves of any blowback.
CAD can also help us understand the environment around us, or in us, and greatly improve it.
The FLOWLab at the University of Colorado Boulder, led by Professor Debanjan Mukherjee, is an interdisciplinary research group that studies biological fluid systems. Within that laboratory, Akshita Sahni is using computer-aided design and 3D printing to create models of large human arteries in order to research how blood moves through them.
“These models are generated from patient CT (Computed Tomography) scan imagery using image segmentation on the open-source cardiovascular modeling package SimVascular,” says Akshita. To replicate a human artery like the carotid artery (which is located in the neck and supplies blood to the brain, neck, and face) in the CAD software SimVascular, hundreds of CT scan images of artery cross sections are stacked on top of each other. The shape of the artery in each CT scan picture is used as a guide to develop a solid model.
“Notice that these segments look much different than a combination of straight tubes,” Akshita pointed out in reference to her artery models. Because the arteries have such organic and varying shapes, it is necessary to use the image-based modeling process in SimVascular that was just explained. Akshita then uses another CAD software called Autodesk Meshmixer to prepare her models for 3D printing.
Akshita, FLOWLab, and their partner University of Colorado Anschutz Medical Campus can learn a lot by studying how fluid that mimics blood moves through 3D printed arteries. How blood flows through the body and through medical implants can affect different infectious or cardiovascular diseases, so understanding that is essential to preventing those diseases and helping diagnosed patients live longer.
Join me in exploring the endless possibilities of CAD!
The engineering work above is exciting, innovative, and literally lifesaving, but it is only four examples of the possibilities that exist because of computer-aided design. I invite you to follow along as I dive deeper into more applications of CAD. Next time, I’ll be using the CAD software SolidWorks to reverse engineer and recreate parts and an assembly from the world of sporting equipment: ski bindings!
Katie Schutt is a sophomore majoring in Mechanical Engineering and minoring in Media Production and Leadership Studies at the University of Colorado Boulder. Katie has used CAD on various robotics, aerospace, and rapid prototyping projects, but is most excited by utilizing computer-aided design in the film industry! She also enjoys skiing, surfing, hiking, and documenting all of those exciting things through photography and videography.
Special thanks to the women who shared their experiences with CAD:
Akshita Sahni is earning her Master of Science in Mechanical Engineering at the University of Colorado Boulder. Akshita has spent multiple years studying fluid dynamics, and currently works in the FLOWLab at CU where she is researching how blood moves through human arteries. She has found a greater purpose through this work that improves the lives of patients with cardiovascular diseases. See more of her work here!
Autumn Zemlicka is majoring in Mechanical Engineering and minoring in Engineering & Industrial Management at the University of Colorado Boulder. Autumn loves engineering design, which allows her to be creative while using her technical skills. She encourages girls interested in engineering design to seek out as many opportunities as possible and not to be daunted by learning new software.
Ioana Dumitru is a Mechanical Engineering undergraduate student in her senior year at the University of Colorado Boulder. Ever since she was a kid, she has loved building things, breaking them, and learning how they worked. She has continued to do this through designing and manufacturing car parts for the CU Formula SAE racing team and custom mechanic shops. Ioana is excited to use her engineering skills to help her community through medical devices or renewable energy in the future. See more of her work here!
Samantha Preston is a design engineer at the medical device company Medtronic. Since her first engineering courses at the University of Colorado Boulder, Samantha knew that she wanted to help others through designing, building, and testing medical devices. In order to do so, she interned with Medtronic while receiving her Bachelor of Science in Mechanical Engineering and a minor in Biomedical Engineering!
Dr. Julie Steinbrenner is a professor in Mechanical Engineering at the University of Colorado Boulder where she mentors students in career development and senior design projects. She connects students and professionals across industries, many of whom were featured in this article!