1.1 Introduction
Learning Objectives:
1) Define a composite
2) Enumerate advantages and drawbacks of composites over monolithic materials,
3) Discuss factors that influence mechanical properties of a composite.
Videos
Title: The incredible properties of composite materials
Summary: This video examines composite materials, which are made up of two or more distinct materials. Composites are engineered to produce materials with highly desirable properties, tailored for specific applications. In the structure of a typical composite, one material – the dispersed phase – is contained within another – the matrix phase. The dispersed phase typically consists of small particles or short or continuous fibers. CFRP, or carbon fiber-reinforced polymer, is one of the most commonly used engineering composites. However, there are many others, including metal-matrix composites and ceramic-matrix composites, which have applications in various industries and fields.
Title: The Insane Engineering of the 787
Summary: This video shows you the insane engineering of the Boeing 787.
Title: The magnificence of spider silk
Summary: Cheryl Hayashi studies spider silk, one of nature’s most high-performance materials. Each species of spider can make up to 7 very different kinds of silk. How do they do it? Hayashi explains at the DNA level — then shows us how this super-strong, super-flexible material can inspire.
Slide Show
Why Bending Rectangular Cross-Section Beam Mass for Same Deflection and Width is Inversely Proportional to E⅓/density [PDF]
Handouts
None
Introduction Slideshow
1.2 Classification
Learning Objectives:
1) Classify composites
2) Introduce common types of fibers and matrices
3) Manufacturing
4) Mechanical properties
5) Applications of composites.
Videos
Title: Different Types of Composite Materials
Summary: This video explains what Composite Materials are as well as their classification. Explaining that concrete is a perfect example of a large Particle Composite where filler material replaces some of the material of the main material. where cement is the matrix and sand/gravel make up the particles. Fiber Reinforced Composites and its main strength is its high stiffness and greater elastic modulus. Where the Fibers can be continuously or discontinuously arranged.
Title: The Basics of Fiberglass Fabric
Summary: This video clip highlights S glass fabric material, emphasizing its chemical modification for increased strength compared to regular glass. This modification allows for using less S glass ounce per ounce, resulting in lighter weight without sacrificing strength. The material, with its 30-inch width, is particularly advantageous for high-performance surfboards where both lightweight construction and high strength are essential.
Title: Composite vs Aluminum Alloy Baseball Bats
Summary: This video discusses the differences between aluminum and composite bats. Aluminum bats tend to be more durable and lighter while composite bats have a larger sweet spot and are able to be tuned to provide a better swing feel. Because of the nature of composites parts of the bat can be made harder and softer. This ability allows the bat to be tuned by moving weight around the bat to provide more power and better swing feel. Lastly by changing the bending stiffness of the bat manufactures are able to reduce the amount of vibration felt by the player when hitting a ball.
Title: Bending Graphite Rods
Summary: This video explains the differences between graphite and fiberglass fishing rods, highlighting the unique characteristics of each. Graphite rods exhibit incredible power and pulling strength, allowing for superior casting performance with various weights such as lures or baits. However, graphite is not as adept at executing tight turns in confined spaces compared to fiberglass. The presenter demonstrates how attempting a tight turn with a graphite rod can result in snapping. Despite this limitation, the benefits of graphite, including casting responsiveness, sensitivity, and lightweight construction, outweigh its drawback in tight turns. Graphite rods are praised for their enormous pulling power when loaded correctly, making them a preferred choice for various fishing scenarios.
Title: Prepreg Layup and Vacuum Bagging
Summary: This video explains what Composite Materials are as well as their classification. Explaining that concrete is a perfect example of a large Particle Composite where filler material replaces some of the material of the main material. where cement is the matrix and sand/gravel make up the particles. Fiber Reinforced Composites and its main strength is its high stiffness and greater elastic modulus. Where the Fibers can be continuously or discontinuously arranged.
Title: Materials Selection
Summary: The selection of any material for use in a part or machine depends on the application. A project may require that a material property (e.g., specific weight, elastic modulus, etc.) of one of the materials used be a certain value or range of values. The cost of the material is also a significant factor in selection. A material may be appropriately selected if the properties of a wide variety of materials are known (through experimental testing) and compared to each other. A composite material (the video gives an example of rubber with an underlayer of steel) may be most appropriate for the application if the material properties for which the engineer seeks are not all present in a singular material. This video focuses on the practice of material selection for the improvement of cars.
Title: Carbon fibre pre-preg lay-up demonstration
Summary: In this video, an engineer demonstrates how to prepare a carbon fiber prepreg to be placed into an autoclave for autoclave forming. First, a prepreg is laid flat against clean metal. The engineer flattens out the prepreg to remove wrinkles or bubbles before another layer is added. In this video, only two prepregs are used, but more than two can be layered on top of another. The carbon fiber prepregs are then wrapped in what is assumed to be Teflon sheets, bagged, and then placed into the autoclave.
Title: Resin Transfer Moulding
Summary: In this video, the process of Resin Transfer Molding (RTM) is explained and shown step-by-step. Some of the advantages of RTM are first explained such as productivity and quality. A surfacing veil is placed on the mold before injection and the mold is then closed using clamps or a press. The resin is then injected, while using liquid heating, until a small amount of resin comes out of the vents. The resin is left to cure before the molding is opened.
Title: Composites Leaf Spring Production
Summary: In this shorter length video, the manufacturing process for a composite leaf spring is demonstrated as well as some composite benefits listed. The process includes insertion of glass fibers followed by injection of resin into a mold under high pressure. The video ends with a list of benefits of composite leaf springs over that of metal ones. This relates to the benefits listed in the book for a Corvette’s composite leaf spring.
Title: Choosing Composite Reinforcements for Impact Strength
Summary: In this video several different fibers are tested to be used as a sled for artic conditions. The testing includes the use of a bending test under room temperature and freezing temperatures, and it includes an impact test. The fibers tested were carbon, Diolen, Innegra, and Kevlar. After testing was completed it was found that for this application the Kevlar fibers would be the best even at their elevated cost.
Title: Advanced Materials (polymer composites)
Summary: This video discusses polymer composites and their role in manufacturing metal matrix composites. It covers the three main categories of MMC: Solid State Processing, Liquid State Processing, and In-Situ Processing. The author then goes further in-depth on the Spray Deposition Process where particle /whisker/short fiber reinforcements are injected into the spray and later cured to form the plastic composite. The video also discusses MMC’s applications in the automobile and Aerospace industries.
Title: How the CMC process works
Summary: This video explains the process that involves melting, spinning, and heat treating the powder that creates a low-density, high-strength, corrosion-resistant silicon carbide fiber that is used in the fabrication of products. To improve the fiber system, the fibers are subsequently coated with four exclusive coatings. The completed strands are fed into a computerized device that precisely forms and sizes the fiber according to specifications. Then, using the high fiber strength qualities across the part’s thickness, the stacked flies are arranged, frequently alternating in fiber direction. After that, the tool is put in an autoclave, which uses high pressure and low heat to shape the stacked plies into a part. Following a burnout process that turns all organic material left in the part into carbon, silicon is melted into the open pores to give density. Next, environmental and thermal protection codes are applied to the part. The CMC part is prepared for service after completing more than 50 steps. Being one of the hardest materials on Earth, silicon carbide CMC, this method guarantees the components’ fit and quality.
Title: Ceramic Matrix Composite Research
Summary: This video expresses the potential advantages of Ceramic Matrix Composite over existing materials in airplane engines that are the driving investment in the Aerospace Industry. Metal-based components can be replaced by ceramics since they are lighter and can withstand higher operating temperatures. In order to assure the safety of Ceramic Matrix Composites and to distinguish them from existing metal-based parts, NASA is pushing the boundaries of these materials’ mechanical, thermal, and temperature capabilities. Compared to traditional methods, 3D printing is being used to create a variety of geometries more quickly and affordably. A more realistic environment is made possible by 3D printing and a burn array, which enables the assessment of thermal capacities. For instance, in a burner rig engine used in an airplane, jet fuel can be fired and temperatures as high as 2,700°F can be reached to assess various components, including ceramics.
Title: NASA 360 Thermal Protection System Tiles Space Shuttle
Summary: This describes the step-by-step production process of space shuttle heat protection tiles and explains how they work. These tiles are essentially ceramic matrix composites with high thermal resistance, extremely low density, and reusability—crucial characteristics for space shuttles. The production begins by blending various types of ceramic fibers with water and adding chemical additives like ammonium hydroxide and silicon carbide. The mixture is then cast into a mold through a de-watering process achieved by applying pressure. After curing and drying, the tiles undergo cutting and shaping processes to prepare them for a series of ceramic coatings. In the final stages, these coatings consolidate in a high-temperature oven.
Title: Are composite materials sustainable?
Summary: This video explains Nanomaterials and their main uses in engineering, electronics, and other things. Nanomaterials, or similarly Nanocomposites must be smaller than 100nm. Natural nanomaterials include volcanic ash or soot from a fire. We need to use a special microscope called a scanning tunneling microscope to see and work on the size of a nanomaterial. Nanomaterials can have increased strength, chemical reactivity, and conductivity. Nano Materials are used to make a wide variety of things including but not limited to sunscreen, cosmetics, tires, tennis equipment, and carbon nanotubes that can be used to make artificial muscles.
Slide Shows
Worked Out Examples
None
Handouts
None
Classification Slideshow
1.3 Recycling
Learning Objectives:
1) Discuss recycling of composites
Videos
Title: Are composite materials sustainable?
Summary: In this video, several industries, their composite type use, and methodology for recycling said composites are covered. It outlines both methodology of recycling and drawbacks to each recycling type, such as incineration possibly rendering fibers unusable in their original form. It goes on to theorize about the rise of biopolymers that may be more easily recycled through simpler and/or more effective processes.
Slide Shows
Worked Out Examples
None
Handouts
None
Recycling Fiber-Reinforced Composites Slideshow
1.4 Mechanics Terminology
Learning Objectives:
1) Introduce terminology used for studying mechanics of composites
Videos
Title: How to Make the Hybrid Hemp-Glass Fiber Reinforced Epoxy Composite
Summary: The video demonstrates creation of a hybrid laminate with hemp fiber, glass fiber, and epoxy. It is a tutorial for the whole fabrication of the hybrid laminate structure. The creation is an interply hybrid laminate. There is no stated purpose to the end-state inclusion of the hemp within the fiber matrix, but the demonstration endures as a useful example of what constitutes a hybrid matrix.
Slide Shows
Worked Out Examples
None
Handouts
None
Mechanics Terminology Slideshow