Evaluation of mode II fatigue disbonding using Central Cut Plies specimen and distributed strain sensing technology

Ribeiro, Fabricio N.; Martinez, Marcias; Rans, Calvin

doi:10.1080/00218464.2018.1433039

Cited by 7 publications

(4 citation statements)

References 41 publications

(70 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A disbond affects the strain distribution locally, although the affected area is not equal to the disbonded area: the surrounding area is also affected. 51,56 The latter means that, from a longitudinal perspective, the region above and below the disbond is affected. From a lateral perspective, it means that the measured strain on a stiffener foot can be influenced by a disbond located at the opposite stiffener foot.…”

Section: Influence Of Load and Damage On Strain Measurementsmentioning

confidence: 99%

“…55 Not only are the strain peaks less distinctive but also a larger strain area is affected by the damage. 51,56 The latter effects make both damage localization and sizing assessments more challenging when employing surface-bonded OFs. In this regard, a finite element model (FEM) can be used to assess the relation between the damage and the strain measurements.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fusion-based damage diagnostics for stiffened composite panels

Broer

Galanopoulos

Benedictus

et al. 2021

Structural Health Monitoring

View full text Add to dashboard Cite

Conducting damage diagnostics on stiffened panels is commonly performed using a single SHM technique. However, each SHM technique has both its strengths and limitations. Rather than straining the expansion of single SHM techniques going beyond their intrinsic capacities, these strengths and limitations should instead be considered in their application. In this work, we propose a novel fusion-based methodology between data from two SHM techniques in order to surpass the capabilities of a single SHM technique. The aim is to show that by considering data fusion, a synergy can be obtained, resulting in a comprehensive damage assessment, not possible using a single SHM technique. For this purpose, three single-stiffener carbon–epoxy panels were subjected to fatigue compression after impact tests. Two SHM techniques monitored damage growth under the applied fatigue loads: acoustic emission and distributed fiber optic strain sensing. Four acoustic emission sensors were placed on each panel, thereby allowing for damage detection, localization, type identification (delamination), and severity assessment. The optical fibers were adhered to the stiffener feet’ surface, and its strain measurements were used for damage detection, disbond localization, damage type identification (stiffness degradation and disbond growth), and severity assessment. Different fusion techniques are presented in order to integrate the acoustic emission and strain data. For damage detection and severity assessment, a hybrid health indicator is obtained by feature-level fusion while a complementary and cooperative fusion of the diagnostic results is developed for damage localization and type identification. We show that damage growth can be monitored up until final failure, thereby performing a simultaneous damage assessment on all four SHM levels. In this manner, we demonstrate that by proposing a fusion-based approach toward SHM of composite structures, the intrinsic capacity of each SHM technique can be utilized, leading to synergistic effects for damage diagnostics.

show abstract

Section: Influence Of Load and Damage On Strain Measurementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fusion-based damage diagnostics for stiffened composite panels

Broer

Galanopoulos

Benedictus

et al. 2021

Structural Health Monitoring

View full text Add to dashboard Cite

show abstract

“…For example, the distributed strain measurements can be employed for the detection and the localization of impact damage in stiffened composite panels [14]. Furthermore, the disbond growth rate under fatigue loading can potentially be sized using distributed strain measurements [13].…”

Section: Introductionmentioning

confidence: 99%

Damage Diagnostics of a Composite Single-Stiffener Panel Under Fatigue Loading Utilizing SHM Data Fusion

Broer

Galanopoulos

Zarouchas

et al. 2021

Lecture Notes in Civil Engineering

View full text Add to dashboard Cite

A case study is presented in which the first steps are made towards the development of a structural health monitoring (SHM) data fusion framework. For this purpose, a composite single-stiffener panel is subjected to compression-compression fatigue loading (R = 10). The carbon-epoxy panel contains an artificial disbond of 30 mm, which was created using a Teflon insert during manufacturing and placed between the skin and the stiffener foot. Under the applied fatigue load, the disbond is expected to grow and its propagation is monitored using two SHM techniques, namely acoustic emission (AE) and Rayleigh-scattering based distributed fiber optic strain sensing. Four AE sensors are placed on the skin, thereby allowing for disbond growth detection and localization. On each stiffener foot, fiber optic sensors are surface-bonded to monitor the growth of the disbond under the applied fatigue loading. The distributed strain measurements are used to localize and monitor the disbond growth. The strength of each technique is utilized by fusing the data from the AE sensors and the fiber optic sensors. In this manner, a data-driven approach is presented in which a data fusion of the different techniques allows for monitoring the damage in the stiffened panel on multiple SHM levels, including disbond growth detection and localization.

show abstract

“…It has been proven that disbond of mode II is the primary cause of crack growth in adhesively bonded joints [20] [21]. For this reason, Central Cut Ply (CCP) specimen, which schematic is shown in Figure 2, has been considered by many authors for understanding the fracture mechanics of mode II [22] [23] [24]. This type of configuration has been chosen as a replacement to other specimen types such as the End Notched Flexure (ENF), the End Loaded Split (ELS), and the four points End Notched Flexure (4ENF), as described in [25] [26] [27] [28] [29].…”

Section: Introductionmentioning

confidence: 99%

Residual stress evaluation of adhesively bonded composite using central cut plies specimens

Baldassarre

Martinez

Rans

2019

The Journal of Adhesion

Self Cite

View full text Add to dashboard Cite

The present study reports on the evaluation of residual stress field formation and distribution in Central Cut Plies (CCP) specimens. Real-time measurements were performed using a distributed sensing fiber optic system based on Rayleigh Backscattering, which was successfully able to capture strain distribution inside the adhesive layer at every 0.65 mm during the entire curing cycle, for both unidirectional and cross ply laminate configurations. A finite element analysis was also performed to cross-correlate with the experimental residual strain distributions in the proximity of the severed central cut plies. The results outlined in this study demonstrate the presences of tensile residual stresses within the adhesive layer for both configurations. A full field strain distribution and the significance of these findings in relation to the use of the CCP test for fracture mechanics testing will be discussed. Results of this study have shown that residual stresses arise after the curing process for which the amount of longitudinal and transverse residual stresses for the unidirectional CCP laminate are 61% and 19% of the total strength of the adhesive respectively, while for the cross-ply CCP laminate are 72% and 71%, respectively.

show abstract

Evaluation of mode II fatigue disbonding using Central Cut Plies specimen and distributed strain sensing technology

Abstract: Rans (2019) Evaluation of mode II fatigue disbonding using Central Cut Plies specimen and distributed strain sensing technology,

Cited by 7 publications

References 41 publications

Fusion-based damage diagnostics for stiffened composite panels

Fusion-based damage diagnostics for stiffened composite panels

Damage Diagnostics of a Composite Single-Stiffener Panel Under Fatigue Loading Utilizing SHM Data Fusion

Residual stress evaluation of adhesively bonded composite using central cut plies specimens

Contact Info

Product

Resources

About