Yearly Archives: 2025

‘Radio-frequency Sensor For Non-destructive Evaluation Of Composite Materials – Nature’

Nature Aug 29, 2025

The growing use of advanced composites in critical applications demands reliable non-destructive testing. Traditional techniques often detect only large defects missing subtle local property changes that can precede major failures. Microwave spectroscopy offers a promising alternative probing both structural and dielectric properties with high sensitivity. This paper presents a novel dual-probe radio-frequency sensor RFlect using open-ended coaxial probes at 2.4ampnbspGHz. Compared to our earlier single-probe design the dual configuration reduces scanning time and enhances detection of surface and subsurface defects including minor cavities and inhomogeneities. It employs a cost-effective system comprising a signal generator directional coupler and RF power measurement setup to improve noise filtering without relying on expensive vector network analyzers. Integrated with a fused deposition modeling 3D printer8217s extruder the sensor scans samples at millimeter resolution. Experiments confirm its ability to detect both visible and hidden subsurface defects by identifying changes in conductivity and dielectric constant. This work underscores the potential of dual-probe microwave spectroscopy as a cost-effective high-performance non-destructive evaluation technique for various applications. Future efforts will focus on characterizing high-loss materials such as biological tissues thereby expanding the sensor8217s use in the biomedical field.

‘Fat-tailed Failure Strength Distributions And Manufacturing Defects In Advanced Composites – Nature’

Nature Jul 17, 2025

This study investigates how manufacturing defects transform the statistical distribution of failure in carbon fiber-reinforced polymer composites under tension and compression loading. The analysis of tension and compression specimens reveals that defect-free composites exhibit relatively narrow unimodal strength distributions. In contrast specimens with porosity or fiber waviness develop more complex multimodal probability densities with fat-tailed distributions and substantially higher variability. Applying Jensen8217s inequality demonstrates that this increased variability can be assessed to identify higher risk profiles. These findings indicate that defects in composites don8217t simply reduce mean strength values but alter the statistical nature of composite failure transforming thin-tailed unimodal well-behaved distributions into multimodal fat-tailed ones. Such transformation necessitates more sophisticated probabilistic approaches for reliable design and strength prediction in safety-critical applications where understanding tail risk becomes crucial to proper risk management.