scholarly journals Smart Inlays for Simultaneous Crack Sensing and Arrest in Multifunctional Bondlines of Composites

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3852
Author(s):  
Chresten von der Heide ◽  
Julian Steinmetz ◽  
Martin J. Schollerer ◽  
Christian Hühne ◽  
Michael Sinapius ◽  
...  
Keyword(s):  
Health Monitoring ◽  
Composite Structures ◽  
Sensory Function ◽  
Film Sensor ◽  
Adhesive Bonds ◽  
Sensor Fabrication ◽  
Manufacturing Procedure ◽  
Static Mechanical ◽  
Micro Sensor ◽  
Cantilever Bending

Disbond arrest features combined with a structural health monitoring system for permanent bondline surveillance have the potential to significantly increase the safety of adhesive bonds in composite structures. A core requirement is that the integration of such features is achieved without causing weakening of the bondline. We present the design of a smart inlay equipped with a micro strain sensor-system fabricated on a polyvinyliden fluorid (PVDF) foil material. This material has proven disbond arrest functionality, but has not before been used as a substrate in lithographic micro sensor fabrication. Only with special pretreatment can it meet the requirements of thin film sensor elements regarding surface roughness and adhesion. Moreover, the sensor integration into composite material using a standard manufacturing procedure reveals that the smart inlays endure this process even though subjected to high temperatures, curing reactions and plasma treatment. Most critical is the substrate melting during curing when sensory function is preserved with a covering caul plate that stabilizes the fragile measuring grids. The smart inlays are tested by static mechanical loading, showing that they can be stretched far beyond critical elongations of composites before failure. The health monitoring function is verified by testing the specimens with integrated sensors in a cantilever bending setup. The results prove the feasibility of micro sensors detecting strain gradients on a disbond arresting substrate to form a so-called multifunctional bondline.

Selection of Materials and Sensors for Health Monitoring of Composite Structures

2003 ◽  
Vol 785 ◽  
Author(s):  
Seth S. Kessler ◽  
S. Mark Spearing
Keyword(s):  
Health Monitoring ◽  
Lamb Wave ◽  
Composite Structures ◽  
Structural Damage ◽  
Performance Metrics ◽  
Full Range ◽  
Transportation Systems ◽  
Health Monitoring Systems ◽  
The Relationship ◽  
Selection Of

ABSTRACTEmbedded structural health monitoring systems are envisioned to be an important component of future transportation systems. One of the key challenges in designing an SHM system is the choice of sensors, and a sensor layout, which can detect unambiguously relevant structural damage. This paper focuses on the relationship between sensors, the materials of which they are made, and their ability to detect structural damage. Sensor selection maps have been produced which plot the capabilities of the full range of available sensor types vs. the key performance metrics (power consumption, resolution, range, sensor size, coverage). This exercise resulted in the identification of piezoceramic Lamb wave transducers as the sensor of choice. Experimental results are presented for the detailed selection of piezoceramic materials to be used as Lamb wave transducers.

Geometrically exact, intrinsic mixed variational formulation for smart, slender multilink composite structures

2021 ◽  
pp. 1045389X2110322
Author(s):  
P M G Bashir Asdaque ◽  
Sitikantha Roy
Keyword(s):  
Composite Structures ◽  
Turbine Blades ◽  
Space Structures ◽  
Wind Turbine Blades ◽  
Weak Formulation ◽  
Helicopter Blades ◽  
Static Mechanical ◽  
Computational Platform ◽  
Swept Wings ◽  
Variational Statement

Flexible links are often part of massive aerospace structures like helicopter or wind turbine blades, satellite bae, airplane wings, and space stations. In the present work, a mixed variational statement based on intrinsic variables is derived for multilinked smart slender structures. Equations involved in the derivation do not involve approximations of kinematical variables to describe the deformation of the reference line or the rotation of the deformed cross-section of the slender links resulting in a geometrically exact formulation. Finite element equations are derived from weak formulation, which can analyze large geometrically non-linear problems. The weakest possible variational statement provides greater flexibility in the choice of shape functions, therefore reducing the associated numerical complexities. The present work focuses on developing a single integrated computational platform which can study multibody, multilink, lightweight composite, structural system built with both embedded actuations, sensing, as well as passive links. Validation of static mechanical and electrical outputs from 3D FE simulation and literature proves the efficacy of the computational platform. Dynamic results will be communicated in future correspondence. The computational platform developed here can be applied for monitoring and active control applications of flexible smart multilink structures like swept wings, multi-bae space structures, and helicopter blades.

scholarly journals Structural health monitoring data fusion for in-situ life prognosis of composite structures

2018 ◽  
Vol 178 ◽  
pp. 40-54 ◽  
Author(s):  
Nick Eleftheroglou ◽  
Dimitrios Zarouchas ◽  
Theodoros Loutas ◽  
Rene Alderliesten ◽  
Rinze Benedictus
Keyword(s):  
Structural Health Monitoring ◽  
Data Fusion ◽  
Health Monitoring ◽  
Composite Structures ◽  
Monitoring Data ◽  
Structural Health ◽  
Life Prognosis

scholarly journals Review of Structural Health Monitoring Methods Regarding a Multi-Sensor Approach for Damage Assessment of Metal and Composite Structures

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 826 ◽  
Author(s):  
Christoph Kralovec ◽  
Martin Schagerl
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Damage Assessment ◽  
Composite Structures ◽  
Joint Damage ◽  
Ultrasonic Waves ◽  
Physical Models ◽  
Monitoring Methods ◽  
Structural Health ◽  
Different Levels

Structural health monitoring (SHM) is the continuous on-board monitoring of a structure’s condition during operation by integrated systems of sensors. SHM is believed to have the potential to increase the safety of the structure while reducing its deadweight and downtime. Numerous SHM methods exist that allow the observation and assessment of different damages of different kinds of structures. Recently data fusion on different levels has been getting attention for joint damage evaluation by different SHM methods to achieve increased assessment accuracy and reliability. However, little attention is given to the question of which SHM methods are promising to combine. The current article addresses this issue by demonstrating the theoretical capabilities of a number of prominent SHM methods by comparing their fundamental physical models to the actual effects of damage on metal and composite structures. Furthermore, an overview of the state-of-the-art damage assessment concepts for different levels of SHM is given. As a result, dynamic SHM methods using ultrasonic waves and vibrations appear to be very powerful but suffer from their sensitivity to environmental influences. Combining such dynamic methods with static strain-based or conductivity-based methods and with additional sensors for environmental entities might yield a robust multi-sensor SHM approach. For demonstration, a potent system of sensors is defined and a possible joint data evaluation scheme for a multi-sensor SHM approach is presented.

Nondestructive health monitoring techniques for composite materials: A review

2020 ◽  
pp. 096739112092170
Author(s):  
M Senthilkumar ◽  
TG Sreekanth ◽  
S Manikanta Reddy
Keyword(s):  
Health Monitoring ◽  
Composite Structures ◽  
Residual Life ◽  
Present Condition ◽  
Nondestructive Technique ◽  
Technical Data ◽  
Monitoring Techniques ◽  
Low Weight ◽  
Marine Applications ◽  
The Impact

Structural health monitoring is the process of acquisition and analyzing technical data obtained from structures to determine the present condition of the structure and residual life. Composites have been widely in use because of their low weight and better mechanical properties compared to conventional metals. They are more prone to damage during cyclic loading and the impact of foreign objects. So, usage of the nondestructive techniques is important to detect such damage in composites at the beginning stage itself, which further helps to avoid catastrophic failure. Many review articles are discussing a single nondestructive technique to monitor the health of the structure, but a single technique is not sufficient in most of the cases. This review is focused on the most commonly used nondestructive health monitoring techniques such as acoustic emission, vibration testing, ultrasonic testing, infrared thermography, and shearography to detect and characterize the damage in composite structures used in aerospace, automotive, and marine applications. The comparison among the techniques also has been presented in this review.

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