Composite Materials and Structures Quiz

<p>Orientation of the fibers (D)</p> Signup and view all the answers

<p>Properties that change with the direction of loading (B)</p> Signup and view all the answers

<p>A single layer of a composite material (B)</p> Signup and view all the answers

<p>Enhanced thermal insulation (C)</p> Signup and view all the answers

<p>They can be oriented to enhance specific strength and stiffness (B)</p> Signup and view all the answers

<p>Honeycomb structure (A)</p> Signup and view all the answers

<p>High-performance automotive tires (D)</p> Signup and view all the answers

<p>Strongest along the fiber direction (B)</p> Signup and view all the answers

<p>They are prefabricated, reducing on-site labor needs (A)</p> Signup and view all the answers

<p>A composite material made from multiple laminas (D)</p> Signup and view all the answers

<p>Higher strength and stiffness along the direction of the fibers (A)</p> Signup and view all the answers

<p>They are randomly oriented in different directions. (C)</p> Signup and view all the answers

<p>Chopped rovings (A)</p> Signup and view all the answers

<p>They remain consistent across all directions. (A)</p> Signup and view all the answers

<p>Rovings are continuous fibers, while chopped rovings are fibers cut into shorter lengths. (A)</p> Signup and view all the answers

<p>Fewer internal defects and greater strength (B)</p> Signup and view all the answers

<p>Random orientation of chopped strands held together by a binder (C)</p> Signup and view all the answers

<p>Filament fibers are continuous and much stronger than bulk materials. (C)</p> Signup and view all the answers

<p>Corrosion resistance (C)</p> Signup and view all the answers

<p>Unlimited availability in FRP sizes (A)</p> Signup and view all the answers

<p>Lower weight (D)</p> Signup and view all the answers

<p>It undergoes a reaction and hardens (A)</p> Signup and view all the answers

<p>Bonding FRP sheets or fabrics to surfaces for structural rehabilitation (D)</p> Signup and view all the answers

<p>Foundation piles and bridge piers (C)</p> Signup and view all the answers

<p>Chemical exposure to saline environments (B)</p> Signup and view all the answers

<p>It softens at high temperatures, typically between 45° to 70°C (B)</p> Signup and view all the answers

<p>Longer lifespan (C)</p> Signup and view all the answers

<p>Impregnation of fiber strands with resin (B)</p> Signup and view all the answers

<p>Environmental degradation (A)</p> Signup and view all the answers

<p>V.ROD® (B)</p> Signup and view all the answers

<p>Reduced need for repairs due to superior corrosion resistance. (D)</p> Signup and view all the answers

<p>It can accommodate increased service loads. (C)</p> Signup and view all the answers

<p>Lower construction costs (B)</p> Signup and view all the answers

<p>Hollow, circular components (D)</p> Signup and view all the answers

<p>ρc = νf ρf + νm ρm (B)</p> Signup and view all the answers

<p>E11 equals Em * νm + Ef * νf. (D)</p> Signup and view all the answers

<p>They are proportional to the amount of fibers in the matrix. (B)</p> Signup and view all the answers

<p>51.42 GPa (B)</p> Signup and view all the answers

<p>The volume fractions of the fibers and matrix (A)</p> Signup and view all the answers

<p>The combined elastic modulus of the composite (D)</p> Signup and view all the answers

<p>The modulus of fibers and matrix as well as their respective volume fractions (B)</p> Signup and view all the answers

<p>Increased strength of the composite (C)</p> Signup and view all the answers

<p>Volume fraction of the fiber (B)</p> Signup and view all the answers

<p>The proportion of fibers to matrix (C)</p> Signup and view all the answers

A single layer of a composite material made of fibers and a matrix.

A layered composite material made by bonding multiple laminas together, often with different fiber orientations, to create a material with specific mechanical properties.

The strength of a fiber when pulled in the direction of its length.

Composite materials with a lightweight core sandwiched between two facing sheets, creating a structure with high strength-to-weight ratio.

A hexagonal pattern often used as the core material in sandwich panels, providing excellent strength and stiffness relative to its weight.

Sandwich panels offer advantages like lightweight construction, insulation, increased strength, and faster construction times, making them suitable for buildings and other applications.

UD stands for 'unidirectional'. It refers to a lamina where fibers run in a single direction.

Laminates are used to tailor the strength and stiffness of composite materials by varying the orientation of fiber layers.

A material that exhibits different mechanical properties (strength and stiffness) in different directions. For example, a composite with continuous fibers will have higher strength along the fiber direction.

A material that has the same mechanical properties in all directions. For example, a composite with randomly oriented discontinuous fibers will have similar strength in all directions.

Fibers that extend continuously throughout the length of a composite material, resulting in an anisotropic material.

Fibers that are not continuous throughout the length of a composite material. They are often randomly oriented, resulting in an isotropic material.

A bundle of untwisted continuous filaments or strands used in composites.

A form of reinforcement used in composites where chopped rovings are randomly deposited and held together by a binder, resulting in an isotropic material.

A single, continuous fiber used in composites.

A bundle of twisted filaments gathered together. It is a type of fiber used in composites.

Various companies produce various types of FRP bar used in construction.

A process for manufacturing hollow, circular components by winding continuous fiber strands impregnated with resin onto a mandrel.

Common products manufactured using filament winding include pipes and tanks.

FRP tanks offer advantages such as corrosion resistance and longer lifespan compared to metal or concrete tanks.

The process of enhancing the structural integrity of existing structures using FRP materials.

Reasons for post-strengthening include deterioration, upgrading needs, and seismic retrofitting.

FRP is often used for post-strengthening due to its high strength-to-weight ratio, corrosion resistance, and ease of application.

FRP post-strengthening is used in various structures including bridge decks, beams, girders, columns, buildings, parking structures.

A material with uniform properties throughout. No matter where you sample it, the material will have the same characteristics.

The ability of a composite material to deform significantly before fracturing. Fibers, especially when properly oriented, enhance the composite's ductility.

Steel fibers increase the toughness, resistance to cracking and fatigue, and overall impact resistance of concrete.

Fiber-Reinforced Polymer (FRP) offers several benefits for structural strengthening, including immunity to corrosion, lightweight design, easy application, high tensile strength, and readily available sizes.

FRP has drawbacks, including linear elastic behavior to failure, relatively high material cost, incompatibility with concrete's thermal expansion, and softening at elevated temperatures (around 45° to 70°C for some epoxy resins).

UD-Strips are thin, approximately 1 mm thick, strips made by pultrusion. They are commonly used in structural strengthening applications.

Prepreg refers to flexible sheets or fabrics impregnated with resin. It comes in one or two directions of fiber alignment and can be used for structural strengthening.

In the prepreg process, a continuous fiber reinforcement is impregnated with resin and then applied to a surface needing strengthening. Multiple sheets are layered to achieve desired thickness, with curing at room temperature.

Wet lay-up is a method for strengthening structures using FRP sheets or fabrics bonded with resin. The process involves applying resin to the material and then layering it onto the structure.

FRP Stay-in-Place Formwork utilizes hybrid FRP and concrete members for innovative structural solutions. Concrete-filled FRP tubes, for instance, offer corrosion resistance and enhanced structural performance.

FRPs are widely used in structural repair and strengthening. Examples include repairing severely corroded steel with carbon FRP wrapping, strengthening bridge girders in shear with carbon FRP, and fixing fatigue damage in aluminum structures using glass FRP wraps.

The density of a composite material is calculated by considering the volume fractions and densities of the individual components (fibers and matrix).

The ratio of the volume of the fibers to the total volume of the composite material. It represents the proportion of fibers within the composite.

The ratio of the volume of the matrix material to the total volume of the composite. It represents the proportion of the matrix within the composite.

When a force is applied to the composite material in the direction of the aligned fibers.

A material property that describes its stiffness or resistance to deformation under stress. It's the ratio of stress to strain in the elastic region of deformation.

The elastic modulus of the composite material when the load is aligned with the fibers, representing its stiffness in the longitudinal direction.

The proportion of the total load applied to the composite that is supported by the fibers.

When a force is applied to the composite material in a direction perpendicular to the aligned fibers.

The elastic modulus of the composite material when the load is perpendicular to the fibers, representing its stiffness in the transverse direction.

An example calculation determining the elastic modulus of a fiberglass composite with known fiber and matrix properties, using volume fractions and material properties of the components.