Summary

In this course, we discussed composite materials, and specifically layered composites. Let’s summarize the key points from each lesson.

Why Composite Materials — Lesson 1  

• Composite materials are composed of two or more constituent materials.
• A very common composite is the layered composite, which is typically made of multiple layers including fibers and matrix materials.
• Composite materials offer benefits such as reduced weight, high stiffness and strength properties with respect to weight, reduced tendency to corrode, and other unique benefits.
• They find their application in a lot of different industries, starting with aerospace, automotive, sports, consumer products, and beyond.
• The major cost of composite parts is associated with the raw material, which requires more complex production processes than metals.
• Challenges with composites include manufacturing high-volume parts, repairing localized damage, and performing necessary care required while fastening composite parts.

Types of Composite Materials — Lesson 2

• The matrix and reinforcement are the primary components of a composite. The type of material used, as well as the reinforcement shape, volume fraction of the reinforcement, and orientation of the reinforcement inside the matrix, can all be used to classify composite materials.
• Composites can be divided into two categories: particle reinforced and fiber reinforced, with each giving distinct advantages in different applications.
• Particle-reinforced composites can be classified based on particle scale size and particle volume fraction.
• Layered composite materials can have different fiber lengths, fiber-to-matrix volume fractions, and fiber-to-matrix arrangement.
• Layered composites usually take the shape of a laminated structure or a sandwich construction. The sandwich structure typically has a high bending and even torsion stiffness to weight ratio.

 Why Layered Composites — Lesson 3  

• Layered composites are one of the most commonly used composites in engineered structures.
• Depending on the application, layered composites can either be simple to create and may be less expensive, or the process could be much more involved with higher costs.
• Layers of composite materials can be easily added and/or oriented to meet the stiffness and strength requirements of a design.
• Layered composites also allow flexibility in different materials used in different layers.
• Layered composites can serve as the perfect choice for modeling complex curved structures due to the layering process over other materials like metals.

 Applications of Layered Composites — Lesson 4  

• Layered composites are a popular choice due to their unique mechanical properties, and thus are employed in a wide range of applications in various industries.
• Layered composites are extensively used in the aerospace and defense sectors due to their unique mechanical properties, including high strength-to-weight ratio, stiffness, and durability.
• Layered composites can be used to build robust, lightweight structures that are also long-lasting, enhancing the vehicle's overall performance and fuel economy. The manufacturing of body panels, such as hoods, trunks, and doors, is one of its most popular uses.
• Consumer products like laminate flooring and kitchen countertops, for example, make use of layered composites.
• One of the most common applications of layered composites in the field of sports is the production of sports equipment such as tennis rackets, golf clubs, archery bows, bike frames, rowing boats, power boats, yachts, kayaks, kayaking paddles, and surfboards. They are also used in the production of sports facilities like artificial turf and running tracks.
• In the biomedical industry, artificial joints, prosthetics, beds, and radiology equipment are some of the applications that make use of layered composites.
• In the electronics sector, layered composites find applications in the production of printed circuit boards (PCBs), smartphone and tablet cases, protective layers for LCD and OLED screens, and so on.
• In the energy sector, layered composites are widely used in wind turbine blades due to their high strength, durability, and lightweight properties. Pipeline industries and pressure vessels are other applications of layered composites.

 Manufacturing Methods of Layered Composites — Lesson 5

• There are various manufacturing methods available for layered composites. Each one has its own benefits that make them a preferred choice for different applications.
• Below are some of the manufacturing methods for layered composites:
  • Wet layup
  • Pre-preg layup
  • Resin transfer molding
  • Automated tape placement
  • Filament winding
  • Thermoforming
• Compaction, vacuum bagging, and autoclave curing are some of the curing processes that are used at the end of the manufacturing process of layered composites to produce the final product.
• Manufacturing layered composites involves several critical considerations to ensure the desired quality and performance of the final product. Some of the key manufacturing considerations are as follows:
  • Cure kinetics
  • Residual stress
  • Post-cure deformation
  • Bonding versus fastening
  • Machining
  • Co-curing