Damage Assessment in Adhesively Bonded Structures by Using SmartSHM

Preisler, Andreas; Sadeghi, Zamaan; Adomeit, André; Schröder, Kai‐Uwe

doi:10.12783/shm2015/27

Cited by 7 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recently, Kouhei et al [17] developed SHM that qualitatively evaluated the structural integrity of the bond-line for CFRP structure by analyzing changes in the amplitude and phase of Lamb waves travelling through bonded components. Preisler et al [18] proposed a strain based SHM system for single and double lap bonded joints which monitored the outof-plane deformation near the edges of the bonded region on the lap joint. However, this study did not address the effects of changes in the adhesive properties due to environmental effects and the load path change at location other than the lap joints.…”

Section: State Of the Artmentioning

confidence: 99%

Temperature dependence of electromechanical impedance based bond-line integrity monitoring

Bilgunde

Bond

2017

Health Monitoring of Structural and Biological Systems 2017

View full text Add to dashboard Cite

Electromechanical impedance (EMI) is an important technique for bond-line integrity monitoring of adhesively bonded joints in automotive and aerospace structures. In the current work, numerical analysis of temperature sensitivity of the EMI technique is performed. The objective is to detect stiffness reduction of the adhesive in the presence of temperature and external mechanical load. Increase in the operating temperature can degrade the bonded piezoelectric material causing misinterpretation of the EMI data. EMI Signal features are numerically investigated to decouple the effect of load and temperature on the piezoelectric material in the mechanically loaded bonded joint. The computational results indicate higher dependence of EM resonance spectrum towards piezoelectric material matrix as compared to the tensile load applied on the bonded sample as the stiffness of adhesive is numerically varied.

show abstract

Section: State Of the Artmentioning

confidence: 99%

Temperature dependence of electromechanical impedance based bond-line integrity monitoring

Bilgunde

Bond

2017

Health Monitoring of Structural and Biological Systems 2017

View full text Add to dashboard Cite

show abstract

“…The pattern propagation considered in this work has been described as ''commonly occurring'' by other authors. 2 The degradation of the bond-line was modeled numerically by reducing the shear modulus in the 10-mm-thick layer in contact with the metal plates (shear modulus reduction, G b# = G b /10). For the geometry and mechanical properties considered, the degradation introduced at the interface corresponds to a value of the shear spring stiffness K T ' 2 3 10 13 Pa/m and the normal spring stiffness K N ' 2.5 3 10 13 Pa/m.…”

Section: Numerical Analysismentioning

confidence: 99%

“…This failure scenario has been reported as relatively common on bonded lap-joint structures. 2 Unlike the case described by the numerical model, in the analytical solution derived by Dugnani and Chang, 20 the damage at the interface is introduced symmetrical on both adhesive-adherend interfaces, hence in the analytical model the damage initiates at both edges and on both interfaces simultaneously. The behavior is approximated by initially letting the magnitude of the far-field transverse spring stiffness decrease progressively from an initial value K T = N (perfect bond) to a final value Based on the analytical model and the damage scenario considered, as the interface damage approaches the near field, the peak frequency Df/f R decreases steeply followed shortly afterward by the conductance.…”

Section: Analytical Modelmentioning

confidence: 99%

See 1 more Smart Citation

Adhesive bond-line degradation detection via a cross-correlation electromechanical impedance–based approach

Dugnani

Zhuang

Kopsaftopoulos

et al. 2016

Structural Health Monitoring

View full text Add to dashboard Cite

This article describes how piezoelectric transducers embedded in the adhesive bond-line of lap-joints can be used to effectively monitor structural integrity. Various lap-joint coupons with embedded piezoelectric transducers were manufactured with and without artificial contamination at the bond-line and tested statically and cyclically. A novel scheme based on the electromechanical impedance response of the transducer was implemented to predict the failure of the tested lap-joint samples. The results from the mechanical testing indicated that monitoring the transducer’s electromechanical impedance is an effective way of predicting the failure of the bond-line. Specifically for static tests, local damage to the bond-line was consistently detected at approximately 84% of the failure load for transducers located at the center of the bond-line, whereas for transducers embedded near the edge of the bond-line, the failure of the adhesive was detected at 60% of the failure load. Moreover, preliminary fatigue tests showed that significant changes in the electromechanical impedance signals were apparent starting at 60% of the life of the bond-line. In addition to the mechanical testing, the effectiveness of the proposed electromechanical impedance–based scheme was investigated by means of a three-dimensional finite element model corresponding to the specific coupon geometry tested and through a two-dimensional analytical solution.

show abstract

“…Instead of proof testing, the Polymers 2022, 14, 3816 2 of 17 regulations can also be fulfilled by limiting the possible disbond size accompanied by some kind of self-triggered repair request. For this, various adhesive layer monitoring systems with different sensory detection principles have been described in the literature [11][12][13][14]. In addition, upon a partial disbond, sensor-equipped design features have to ensure that a critical size of intact bond area is maintained under all circumstances [15].…”

Section: Introductionmentioning

confidence: 99%

Polyetherimide-Reinforced Smart Inlays for Bondline Surveillance in Composites

et al. 2022

View full text Add to dashboard Cite

An integrable sensor inlay for monitoring crack initiation and growth inside bondlines of structural carbon fiber-reinforced plastic (CFRP) components is presented in this paper. The sensing structures are sandwiched between crack-stopping poly(vinyliden fluoride) (PVDF) and a thin reinforcing polyetherimide (PEI) layer. Good adhesion at all interfaces of the sensor system and to the CFRP material is crucial, as weak bonds can counteract the desired crack-stopping functionality. At the same time, the chosen reinforcing layer must withstand high strains, safely support the metallic measuring grids, and possess outstanding fatigue strength. We show that this robust sensor system which measures the strain at two successive fronts inside the bondline allows for crack recognition in the proximity of the inlay regardless of mechanical loading. Feasibility is demonstrated by static load tests as well as cyclic long-term fatigue testing for up to 1,000,000 cycles. In addition to pure crack detection, crack distance estimation based on sensor signals is illustrated. The inlay integration process is developed with respect to industrial applicability. Thus, implementation of the proposed system could potentially lead to better exploitation of lightweight CFRP constructions by expanding the possibilities of structural adhesive bonding.

show abstract

Damage Assessment in Adhesively Bonded Structures by Using SmartSHM

Cited by 7 publications

References 0 publications

Temperature dependence of electromechanical impedance based bond-line integrity monitoring

Temperature dependence of electromechanical impedance based bond-line integrity monitoring

Adhesive bond-line degradation detection via a cross-correlation electromechanical impedance–based approach

Polyetherimide-Reinforced Smart Inlays for Bondline Surveillance in Composites

Contact Info

Product

Resources

About