Good for students and industry
By Leslie Mertz
Few people think about the materials that make up the cars they drive, the jetliners they board or the bridges they traverse, but students taking courses in composites at Michigan State University (MSU) do. Enrolled in a collection of classes offered by the College of Engineering, many of these students are also conducting composites research in one of the numerous high-tech labs in MSU’s Composite Materials and Structures Center in East Lansing, MI.
“A separate degree program in composite materials is not advisable, because when a company hires an engineer, they want a mechanical engineer or a civil engineer or a chemical engineer who understands and can utilize composites, rather than a composites engineer who is an expert in only that field,” says Lawrence T. Drzal, director of the Composite Materials and Structures Center and university distinguished professor of chemical engineering and materials science. “What an engineer does need is a concentration of courses in composites that are translatable to different areas.”
COMPOSITE COURSES COVER THE BASES
Currently, MSU offers 16 classes on composites.
“The courses basically cover all aspects of composite materials: atomic, molecular-level phenomena that look at the polymer chemistry structure and fiber structure; investigating how to put composites together and what properties the resulting composites have; examining how to design with them; and studying how to use nondestructive inspection techniques to find out if there are defects in them,” Drzal says. “Together, these courses represent a continuum across the spectrum from the molecular level to the structural level.”
Some of the courses are directed at senior undergraduate and entry-level graduate students who don’t yet have a background in plastics and composites, and others are graduate courses that tend to emphasize specific aspects of composites, Drzal says. An example of the latter is the “Nonlinear Structural Mechanics” course that provides knowledge about the behavior of composite-built structures, which are often very different from those of metal or concrete structures.
Another example is a course taught by Drzal called “Surface and Interfaces of Composite Materials.”
“We talk about things like composites that are made by combining reinforcing fibers with a plastic, where the fibers can be made of carbon, glass, Kevlar®, polyethylene or any number of other materials, and the plastic is the glue to hold the material together,” he says. Here, the students learn about adhesion between the fiber and the plastic matrix, as well as how to join composites to other materials, such as bonding a cured epoxy carbon fiber composite to aluminum.
BUILDING A FOUNDATION
Undergraduate and graduate students select from a wide range of courses to form individualized concentrations that best suit their future career needs. Often, their classmates include continuing education students who are full-time employees and need to update skills to enhance their work performance or augment future career prospects.
All courses in composites are electives, and although students often have little room in their schedules for additional courses, composites remain attractive options. That is especially true for forward-thinking students who see the importance of building a broad foundation that can be useful in many engineering careers, Drzal says, noting that students with a composites background are simply more marketable.
“If you meet with people in industry where the topic is composites for structural applications, the big question that comes up is, ‘Where am I going to get properly trained employees to do this work?’ That is why this concentration is important for the education of our undergraduate and graduate students, and also for retraining engineers in the workplace,” says Drzal.
BEYOND THE CLASSROOM
Beyond the classroom, graduate students and some talented undergraduate students also join one of two-dozen active, faculty-led composites-research groups associated with the Composite Materials and Structures Center.
“One of the major emerging directions is the increased emphasis on integrating modeling and simulation with composite materials. This will enable design and manufacturing processes to be accomplished much faster in the near future,” says Drzal.
In the example of bonding a composite to aluminum, for instance, researchers might develop and use a computer model to predict whether a particular option would be successful, rather than conducting fabrication and testing with actual materials in the laboratory, which can be quite time-consuming.
“To do that, we have to develop the model, then verify the model with experiments, and continue to refine the model until we have one that works well,” Drzal says. “There’s a lot of effort going on in that direction and we have many students involved.”
Students in the research groups also learn about state-of-the-art equipment. The Composite Materials and Structures Center and its affiliated laboratories occupy about 7,500 square feet in the Herbert H. and Grace A. Dow Institute for Materials Research. Much of that expanse is laboratory space, filled with high-tech equipment, including:
• Characterization equipment. Examples include a scanning electron microscope integrated with a dual-focused ion beam and energy-dispersive detector; an X-ray photoelectron spectrometer for measuring the surface chemistry and composition of materials; a specialized atomic force microscopy (AFM)-scanning probe microscope for imaging materials at the atomic level; an ultraviolet–visible spectrometer; Raman spectrometer with three lasers; and two contact angle goniometers for wettability studies.
• Composite-processing equipment. Examples include multiple ball mills and cryogrinders for size reduction; ultrasonicinators for dispersion of nanomaterials in solutions; a three-roll mill for blending nanomaterials in resins; ultraviolet light modules for photo-initiated reaction and surface modification; and ultraviolet ozone treatment systems for surface oxygenation of fibers and polymers.
• Infrastructure equipment. Facilities include a structural test bay; structural fire laboratory; hydraulic loading equipment; dynamic and non-dynamic actuators; and a large-scale pendulum impact tester.
By taking part in research projects, students get hands-on experience with the advanced equipment. In addition, many of the courses integrate laboratory demonstrations so students who aren’t part of the research teams can gain an understanding of equipment capabilities.
PREPARING FOR THE FUTURE
Between the equipment, active research projects and courses, Drzal feels MSU’s Composite Materials and Structures Center is helping to build the engineering force of the future. Composite materials is a rapidly expanding field that is already touching nearly every industry, he says, and that is precisely why there is a growing need for engineers with a broad foundation that includes composites.
“What we want to do with our composites concentration is to expose our students to a breadth and depth that has applications in many different areas, and that’s exactly what I think we are doing,” Drzal says. “We are preparing our students for the career opportunities of the future.”
What Are Composites?
If ever something fit the concept of “the whole is more than the sum of its parts,” it is a composite material. Composites are made from two — sometimes more — very different constituent materials that are combined to create a material with new characteristics. Fiberglass, for instance, is a composite of plastic reinforced with glass fibers.
Fiberglass has been around for decades, but today’s demand for new composite materials has never been higher.
“A major direction currently driving the need for composites is the improvement of vehicle efficiency,” says Lawrence Drzal, director of the MSU Composite Materials and Structures Center. He points to new greenhouse gas and fuel economy standards stipulating that cars and light trucks get 55 miles per gallon by 2025.
“To achieve that, we are going to have to reduce the weight of the vehicle. The real advantage of composites is that they provide equivalent structural performance at a much lower weight, leading to large increases in fuel economy.”
Lightweight, stiffness and strength must go hand in hand with cost effectiveness, he says.
“Studies are already showing that we can replace a steel structure with a carbon-fiber/epoxy structure and reduce the weight by 60 percent, but if we did that for a vehicle, nobody would be able to afford to buy it because of the high cost of aerospace-grade carbon fibers. There is a large effort under way to reduce the cost of carbon fibers to take advantage of their attractive properties.”
The benefits of composites go well beyond cars. Drzal gives the example of a bridge that weighs 500 tons when made of traditional materials, such as steel and concrete, versus a composite-made bridge that weighs 300 tons.
“It might not seem like a big difference, but when that bridge needs to be repaired or replaced, we can manufacture a composite bridge in a few components off-site, transport it to the site because it’s much lighter, and actually load it into position, causing minimal disruption in traffic. Plus, if we use polymer composites instead of concrete in making that bridge, the polymer composites provide a much more durable structure,” he says.
This increasing interest in composites from multiple industries underscores the need for the MSU Composite Materials and Structures Center, as well as its sister Composite Vehicle Research Center, the Civil Infrastructure Laboratory and the new-in-2015 Institute for Advanced Composites Manufacturing Innovation, Drzal says.
“The composite-materials field is a highly interdisciplinary one that has aspects involving chemical, civil, mechanical, materials and electrical engineering. The composite materials knowledge present in these MSU centers creates a critical concentration to address the growing need for these new and important materials.