Related Experiment Video
Updated: Aug 3, 2025
07:53
Cutting Procedures, Tensile Testing, and Ageing of Flexible Unidirectional Composite Laminates
Published on: April 27, 2019
8.3K
Damage Propagation by Cyclic Loading in Drilled Carbon/Epoxy Plates
Luis M P Durão1,2, João E Matos1, Nuno C Loureiro3,4
1ISEP, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 4249-015 Porto, Portugal.
Materials (Basel, Switzerland)
|April 13, 2023
Summary
Drilling carbon/epoxy composites creates damage that reduces fatigue strength. Understanding this damage is key to predicting the performance of load-bearing composite parts under cyclic stress.
Area of Science:
- Materials Science
- Mechanical Engineering
- Composite Materials
Background:
- Fiber reinforced composites are crucial for load-bearing structures.
- Drilling operations for assembly can introduce critical flaws.
- Holes in composites act as stress concentrators, initiating damage.
Purpose of the Study:
- To investigate the impact of drilling on carbon/epoxy composites.
- To assess the damage zone around drilled holes using radiographic imaging.
- To evaluate the effect of drilling-induced damage on bearing fatigue performance.
Main Methods:
- Drilling carbon/epoxy plates with various drill geometries.
- Monitoring thrust forces during drilling.
- Radiographic inspection to quantify damage area and features.
- Performing bearing fatigue tests on drilled specimens.
Main Results:
- Drilling-induced damage was characterized and quantified.
- Cyclic loading led to hole ovality and significant bearing strength loss (approx. 10%).
- A correlation was observed between damage extension and reduced fatigue resistance.
Conclusions:
- Drilling-induced damage significantly compromises the fatigue life of composite parts.
- Damage assessment is crucial for predicting the load-carrying capacity under cyclic loading.
- Findings aid in designing more resilient composite structures for fatigue-critical applications.
More Related Videos
07:37Full-field Strain Measurements for Microstructurally Small Fatigue Crack Propagation Using Digital Image Correlation Method
Published on: January 16, 2019
9.7K
09:54Author Spotlight: Enhancing Fiber Composite Laminate Quality with the Wet Hand Lay-Up/Vacuum Bag Process
Published on: June 30, 2023
2.2K
Related Concept Videos
01:21Fatigue
217
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...
217
01:20Plastic Deformation in Circular Shafts
212
When materials are subjected to forces that surpass their yield strength, they undergo a process known as plastic deformation. This results in a permanent alteration or strain in their structure. This concept can be specifically applied to circular shafts, where the deformation leads to a change in its shape. The precise evaluation of this plastic deformation requires understanding the stress distribution within the circular shaft, which is achieved by calculating the maximum shearing stress in...
212
01:19Impact Loading
242
Impact loading occurs when a moving object collides with a stationary structure, such as a rod with a uniform cross-sectional area fixed at one end. Under these conditions, the rod absorbs the kinetic energy from the striking object, leading to deformation and subsequent stress development. As the rod returns to its original position and reaches maximum stress, the absorbed energy, initially manifested as kinetic energy, transforms entirely into strain energy.
In cases of elastic deformation,...
In cases of elastic deformation,...
242
01:18Residual Stresses in Bending
218
In the study of elastoplastic members subjected to bending moments, understanding the loading and unloading phases is crucial for assessing material behavior and structural integrity. During the loading phase, as the bending moment increases, the material initially responds elastically, adhering to Hooke's Law, where stress is directly proportional to strain. When the load exceeds the yield strength, plastic deformation occurs, resulting in permanent strain and deformation that remains even...
218
01:15Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
306
Deformation occurs in axial and transverse directions when an axial load is applied to a slender bar. This deformation impacts the cubic element within the bar, transforming it into either a rectangular parallelepiped or a rhombus, contingent on its orientation. This transformation process induces shearing strain. Axial loading elicits both shearing and normal strains. Applying an axial load instigates equal normal and shearing stresses on elements oriented at a 45° angle to the load axis.
306
01:16Eccentric Loading
451
Eccentric loading is a crucial concept in the study of structural engineering and mechanics, particularly when analyzing the stability and stress distribution in columns. Unlike centric loading, where the force is applied along the centroidal axis, causing uniform compression, eccentric loading occurs when a force is applied off-center. This off-center application introduces not only direct compressive stress but also bending stress, significantly influencing the column's behavior under...
451