What are the advantages and disadvantages of using composite materials for dynamic structures?

1 What are composite materials?

Composite materials are made of two or more different materials that are combined to create a new material with improved properties. The most common types of composite materials are fiber-reinforced composites, where fibers of one material (such as carbon, glass, or aramid) are embedded in a matrix of another material (such as epoxy, polyester, or thermoplastic). The fibers provide strength and stiffness, while the matrix provides protection and shape. Composite materials can be designed to have specific characteristics, such as high strength-to-weight ratio, anisotropy, damping, and thermal expansion.

2 Why use composite materials for dynamic structures?

Dynamic structures, which undergo vibrations, motions, or changes in shape due to external forces, such as wind, gravity, or loading, can benefit from composite materials. These materials are lighter than conventional materials, such as metals, reducing the overall mass and inertia of the structure and thus the energy required to move it. Additionally, they can be tailored to have different properties in different directions, improving stiffness, strength, and flexibility of the structure. For example, they can create adaptive wings that can change shape and aerodynamics according to the flight conditions. Moreover, composite materials can withstand harsh environments better than conventional materials and absorb more energy and dissipate more vibrations to reduce the risk of damage and failure.

3 What are the challenges of using composite materials for dynamic structures?

Despite the advantages of composite materials, they can also present some difficulties for dynamic structures due to their complexity and cost. Composite materials require more sophisticated design, fabrication, and testing methods than conventional materials, as well as specialized skills and equipment to handle and maintain. Moreover, they have more variables and interactions that affect their behavior, making them difficult to model and analyze. Furthermore, composite materials have more variability and scatter in their properties and performance than conventional materials, making them more sensitive to defects, flaws, and environmental factors. Additionally, there is less data and experience to support their design and certification, which can increase the uncertainty and risk involved.

5 What are some examples of composite materials for dynamic structures?

Composite materials are used in a variety of dynamic structures across various domains and applications, such as the wings, fuselage, tail, and other components of aircraft to reduce weight and increase performance. Wind turbines use composite materials for the blades, nacelle, and tower to increase efficiency and adaptability. Bridges use composite materials for the decks, cables, girders, and joints to improve strength and flexibility. Additionally, composite materials are used for the frames, shafts, rackets, and balls of sports equipment to enhance performance and comfort. For instance, the Boeing 787 Dreamliner is made of 50% composite materials by weight and the Wilson Clash tennis racket is made of carbon fiber with a unique geometry that allows it to bend and snap back with more power and control.