Related Experiment Video
Updated: Apr 21, 2026
09:54
Author Spotlight: Enhancing Fiber Composite Laminate Quality with the Wet Hand Lay-Up/Vacuum Bag Process
Published on: June 30, 2023
3.1K
Fracture Toughness Micromechanics by Energy Methods With a Photocure Fiber-Reinforced Composite
Richard C Petersen1, Jack E Lemons2, Michael S McCracken3
1Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama 35294.
Polymer Composites
|October 28, 2014
Summary
This study shows that fiber volume percent significantly impacts fracture toughness in composites. Increased fiber content enhances resilience and work of fracture, crucial for material strength.
Area of Science:
- Materials Science
- Mechanical Engineering
- Composite Materials
Background:
- Fracture toughness is critical for composite material performance.
- Understanding the influence of fiber reinforcement on fracture mechanics is essential for designing durable materials.
Purpose of the Study:
- To analyze fracture toughness in discontinuous fiber reinforcement as a function of fiber volume percent (Vf).
- To assess the impact of Vf on material resilience, work of fracture (WOF), and strain energy release rate (SERIC).
Main Methods:
- Utilized advanced flexural bend tests with fully articulated fixtures.
- Employed Euler-type bending to minimize shearing effects in specimens.
- Calculated fracture toughness using mechanics-of-materials energy methods and numerical integration of load-deflection curves.
Main Results:
- Fiber volume percent (Vf) significantly correlated with resilience, WOF, and SERIC (p < 0.0000005).
- Higher Vf negatively correlated with crack depth.
- Significant differences in fracture toughness emerged at specific Vf thresholds for fiber-reinforced composites compared to particulate-filled ones.
Conclusions:
- Fiber volume percent is a key determinant of fracture toughness in discontinuous fiber composites.
- The study quantifies the critical Vf levels for improved mechanical properties, offering insights for material design.
- The findings provide a basis for optimizing composite structures for enhanced durability and performance.
Related Concept Videos
01:21Fatigue
1.1K
Fatigue occurs when materials rupture under repeated or fluctuating loads, even at stress levels far below their static breaking strength. It typically results in brittle failure, even for ductile materials. It is a critical consideration in designing machines and structural components subjected to repetitive or varying loads. The nature of these loadings can range from fluctuating loads like unbalanced pump impellers causing vibrations to repeatedly bending a thin steel rod wire back and forth...
1.1K
01:22Fiber Reinforced Concrete
617
Fiber-reinforced concrete significantly enhances the structural and nonstructural properties of traditional concrete by incorporating fibers like steel, glass, and polymers. These fibers, varying from natural ones such as sisal and cellulose to manufactured ones like polypropylene and Kevlar, are mixed into hydraulic cement with aggregates. Steel fibers, often preferred for their robustness, contribute to improved ductility, toughness, and post-cracking performance. The concrete is classified...
617
01:20Microcracking in Concrete
604
Microcracking in concrete refers to the tiny cracks that can form within the material even before any external load is applied. These microcracks typically occur at the interface between the coarse aggregate and the hydrated cement paste, often as a result of differential volume changes prompted by variations in stress-strain behavior, as well as thermal and moisture movement. Initially, these microcracks remain stable and do not grow substantially until the concrete is stressed to about 30...
604
01:24Stress-Strain Diagram - Brittle Materials
4.3K
Brittle materials, including glass, cast iron, and stone, exhibit unique characteristics. They fracture without considerable change in their elongation rate, indicating that their breaking and ultimate strength are equivalent. Such materials also show lower strain levels at the point of rupture. The failure in brittle materials predominantly results from normal stresses, as evidenced by the rupture created along a surface perpendicular to the applied load. These materials do not display...
4.3K
01:16Tensile Strength Considerations of Concrete
1.6K
Considering the tensile strength of concrete involves recognizing that the theoretical strength of cement paste can be up to a thousand times higher than what is observed in practical applications. This significant discrepancy is largely attributed to the presence of microscopic cracks within the concrete. These cracks tend to amplify stress at their tips when a load is applied, a phenomenon explained by Griffith's theory of brittle fracture.
The dimensions and shape of a concrete specimen...
The dimensions and shape of a concrete specimen...
1.6K
01:18Mechanical Characteristics of Steel
927
The mechanical characteristics of steel are assessed through various tests that evaluate its strength, toughness, and flexibility. These tests include tension, torsion, impact, bending, and hardness assessments, each providing crucial information about steel's suitability for specific applications.
The tension test is fundamental for determining tensile strength. In this test, a steel specimen is stretched using a gripping device until it breaks. The data collected during this test are used...
The tension test is fundamental for determining tensile strength. In this test, a steel specimen is stretched using a gripping device until it breaks. The data collected during this test are used...
927