Journal articles: 'Debond effect'

1

Sikdar, Shirsendu, Abhishek Kundu, Michał Jurek, and Wiesław Ostachowicz. "Nondestructive Analysis of Debonds in a Composite Structure under Variable Temperature Conditions." Sensors 19, no. 16 (August 7, 2019): 3454. http://dx.doi.org/10.3390/s19163454.

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This paper presents a nondestructive analysis of debonds in an adhesively-bonded carbon-fibre reinforced composite structure under variable temperature conditions. Towards this, ultrasonic guided wave propagation based experimental analysis and numerical simulations are carried out for a sample composite structure to investigate the wave propagation characteristics and detect debonds under variable operating temperature conditions. The analysis revealed that the presence of debonds in the structure significantly reduces the wave mode amplitudes, and this effect further increases with the increase in ambient temperature and debond size. Based on the debond induced differential amplitude phenomenon, an online monitoring strategy is proposed that directly uses the guided wave signals from the distributed piezoelectric sensor network to localize the hidden debonds in the structure. Debond index maps generated from the proposed monitoring strategy show the debond identification potential in the adhesively-bonded composite structure. The accuracy of the monitoring strategy is successfully verified with non-contact active infrared-thermography analysis results. The effectiveness of the proposed monitoring strategy is further investigated for the variable debond size and ambient temperature conditions. The study establishes the potential for using the proposed damage index constructed from the differential guided wave signal features as a basis for localization and characterization of debond damages in operational composite structures.

2

Varna, Janis, Lin Qi Zhuang, Andrejs Pupurs, and Zoubir Ayadi. "Growth and Interaction of Debonds in Local Clusters of Fibers in Unidirectional Composites during Transverse Loading." Key Engineering Materials 754 (September 2017): 63–66. http://dx.doi.org/10.4028/www.scientific.net/kem.754.63.

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Fiber/matrix debonding in transverse tensile loading of a unidirectional composite is analyzed calculating energy release rate (ERR) for interface crack propagation. Non-uniform fiber distribution (local hexagonal fiber clustering) is assumed in the model. The matrix region containing the central fiber with the debond and the 6 surrounding fibers is embedded in a large block of homogenized composite which has the same fiber content as the region analyzed explicitly. Some of the fibers surrounding the central fiber may also have a debond. The effect of the local clustering and of the presence of other debonds on magnification of the ERR is analyzed.

3

Quispitupa Yupa, A., and C. Berggreen. "Effect of Initial Debond Crack Location on the Face/core Debond Fracture Toughness." EPJ Web of Conferences 6 (2010): 24004. http://dx.doi.org/10.1051/epjconf/20100624004.

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Gong, Wen Ran, Jin Long Chen, and Jiao Wang. "Debond Propagation in Honeycomb Structure under Pure Bending Load." Applied Mechanics and Materials 37-38 (November 2010): 284–87. http://dx.doi.org/10.4028/www.scientific.net/amm.37-38.284.

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This paper used Finite Element Method to investigate the influence of the circular face-core debonding dimension on the further debond propagation under the pure bending load in honeycomb structure. We also summarized the debonding rules and looked further into debonding area effect on the critical load for debond propagation. The conclusions are as follows: For a honeycomb panel, there exists a certain debonded radius . When the initial debonded radius is greater than , it will experience local buckling which takes the form of snap-through buckling. The debonding propagation is only discovered on the wide direction of the plate. The critical load for debonding propagation decreases with increased debond size.

5

Turk, Tamer, Selma Elekdag-Turk, Devrim Isci, Fethiye Cakmak, and Nurhat Ozkalayci. "Saliva Contamination Effect on Shear Bond Strength of Self-etching Primer with Different Debond Times." Angle Orthodontist 77, no. 5 (September 1, 2007): 901–6. http://dx.doi.org/10.2319/100906-415.

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Abstract Objective: To evaluate shear bond strengths (SBSs) of a self-etching primer (SEP) following saliva contamination at different stages of bonding at debond times of 5, 15, and 30 minutes and 24 hours. Materials and Methods: Two-hundred forty human premolars were divided into four groups: group 1, uncontaminated; group 2, saliva contamination after priming; group 3, saliva contamination before priming; and group 4, saliva contamination before and after priming. Four subgroups according to debond times of 5, 15, 30 minutes and 24 hours were composed. Metal brackets were bonded with an SEP (Transbond Plus) and light-cure adhesives paste (Transbond XT). SBS values and the adhesive remnants were determined. Results: The highest SBS was obtained at a debond time of 24 hours for the control group. This was significantly different from the other groups. SBSs at 5, 15, and 30 minutes showed no significant difference from each other in the control group (P > .05). Lowest SBSs were obtained at a debond time of 5 minutes for groups 1, 2, 3, and 4 (8.38, 7.10, 7.06, and 6.26 MPa, respectively) and were not significantly different from each other (P > .05). SBSs at 24 hours were not significantly different from each other for groups 2, 3, and 4 (P > .05). Significant differences were found in the adhesive remnant (P < .001). Conclusions: SEP (Transbond Plus) may produce clinically acceptable bracket bonding after 5, 15, and 30 minutes from time of placement on the teeth, even with light and heavy saliva contamination.

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Turk, Tamer, Selma Elekdag-Turk, and Devrim Isci. "Effects of Self-Etching Primer on Shear Bond Strength of Orthodontic Brackets at Different Debond Times." Angle Orthodontist 77, no. 1 (January 1, 2007): 108–12. http://dx.doi.org/10.2319/011606-22r.1.

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Abstract Objective: To evaluate the effect of a self-etching primer on shear bond strengths (SBS) at the different debond times of 5, 15, 30, and 60 minutes and 24 hours. Materials and Methods: Brackets were bonded to human premolars with different etching protocols. In the control group (conventional method [CM]) teeth were etched with 37% phosphoric acid. In the study group, a self-etching primer (SEP; Transbond Plus Self Etching Primer; 3M Unitek, Monrovia, Calif) was applied as recommended by the manufacturer. Brackets were bonded with light-cure adhesive paste (Transbond XT; 3M Unitek) and light-cured for 20 seconds in both groups. The shear bond test was performed at the different debond times of 5, 15, 30 and 60 minutes and 24 hours. Results: Lowest SBS was attained with a debond time of 5 minutes for the CM group (9.51 MPa) and the SEP group (8.97 MPa). Highest SBS was obtained with a debond time of 24 hours for the CM group (16.82 MPa) and the SEP group (19.11 MPa). Statistically significant differences between the two groups were not observed for debond times of 5, 15, 30, or 60 minutes. However, the SBS values obtained at 24 hours were significantly different (P < .001). Conclusions: Adequate SBS was obtained with self-etching primer during the first 60 minutes (5, 15, 30 and 60 minutes) when compared with the conventional method. It is reliable to load the bracket 5 minutes after bonding using self-etching primer (Transbond Plus) with the light-cure adhesive (Transbond XT).

7

Stasio, Luca Di, Janis Varna, and Zoubir Ayadi. "Effect of the proximity to the 0°/90° interface on Energy Release Rate of fiber/matrix interface crack growth in the 90°-ply of a cross-ply laminate under tensile loading." Journal of Composite Materials 54, no. 21 (March 22, 2020): 3021–34. http://dx.doi.org/10.1177/0021998320912810.

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Models of Representative Volume Elements of cross-ply laminates with different geometric configurations and damage states are studied. Debond growth is characterized by the estimation of the Mode I and Mode II Energy Release Rate using the Virtual Crack Closure Technique. It is found that the presence of the [Formula: see text] interface and the thickness of the [Formula: see text] layer has no effect, apart from laminates with ultra-thin [Formula: see text] plies where it is however modest. The present analysis supports the claim that debond growth is not affected by the ply-thickness effect.

8

Sutcu, M., and W. B. Hillig. "The effect of fiber-matrix debond energy on the matrix cracking strength and the debond shear strength." Acta Metallurgica et Materialia 38, no. 12 (December 1990): 2653–62. http://dx.doi.org/10.1016/0956-7151(90)90278-o.

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9

Ziao, J., and J. Tao. "Investigation of Interlaminar Defects and their Influence on Interlaminar Strength." Advanced Composites Letters 5, no. 4 (July 1996): 096369359600500. http://dx.doi.org/10.1177/096369359600500404.

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In this paper, we directed our attention to the interlaminar defects and their influence on the interlaminar strengths. With the aid of a S-570 scanning electron microscope, the morphology and distribution of interlaminar defects were inspected and documented. According to their shape, size and cause of formation, the defects were classified into five types: flakiness void, irregular shaped debond, local imperfectly cured resin, debond in two multi-directional plies, and inhomogeneous fibers and the large scale debond by these fibers. The cause of defects formation was discussed by analyzing the manufacturing process of composites. The influence of defects on the interlaminar strength and its mechanism was analyzed experimentally and theoretically. The results indicate that these defects, with different effects, decrease the interlaminar strength because they form interlaminar cracks, and the interlaminar shear strength is less affected than interlaminar tensile strength, which is measured according to GB4944 test method. To comprehend defects distribution effect, a four-point-bending test method was introduced to measure the interlaminar peel strength, and a discussion was made on the correlation between the interlaminar tensile strength, interlaminar peel strength and in-plane transverse tensile strength. Finally the concept of interlaminar defect coefficient, which can be used to characterize the defects, was set up and the formula to calculate it was proposed.

10

Medalia, Avrom I. "Effect of Carbon Black on Ultimate Properties of Rubber Vulcanizates." Rubber Chemistry and Technology 60, no. 1 (March 1, 1987): 45–61. http://dx.doi.org/10.5254/1.3536121.

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Abstract In this survey, we have concluded that carbon black reinforces ultimate properties of rubber by tear deviation. This can occur at the colloidal level, as the tear is forced to pass around carbon black aggregates, thus increasing the area of the torn surface. Colloidal tear deviation may be the cause of the increase in threshold tearing energy which appears to be a small but significant component of reinforcement. Most reinforcement under ordinary test conditions is due to macroscopic tear deviation. This appears to be caused by strands of carbon black aggregates which force the growing tear to change direction. Macroscopic tear deviation is readily observed in a trouser tear test as stick-slip or knotty tear. In the tensile strength test, tear deviation prevents catastrophic rupture until a high stress is reached. In order to be effective in this or other ultimate properties, the carbon black must not debond; i.e., failure must go through the rubber rather than through the debonded rubber—filler interface. Reinforcing carbon blacks do not debond (from diene rubbers) under normal conditions and so do not require further strengthening of the rubber—filler bonds.

11

Guo, Xia, Zeng Shan Li, Wen Chao Zhang, Ri Ming Tan, and Zhi Dong Guan. "Mechanical Performance Analysis of Composite Scarf Joints with Debond Flaw." Advanced Materials Research 1016 (August 2014): 95–99. http://dx.doi.org/10.4028/www.scientific.net/amr.1016.95.

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The adhesive structural mechanical performance is influenced by debond flaw. This paper presents a research on the effect of flaws on the mechanical performance of composite scarf joints. The experimental results show that the load-carrying capacity of composite scarf joints changed along with the location of the debond flaw. The location of the flaw in the bondline influences the failure mode. Additionally, the finite element method was employed to obtain the failure mode of the composite scarf joint. The adhesively bonded joints were modeled using ABAQUS software. The computational results show that flaws located at the edge of the bond region result in more pronounced load reduction than which located at the middle of bond region.

12

Yuan, Yi Yun, Qi Jun Wu, Da Peng Yang, and You Dong Ye. "Monte Carlo Simulation on the Matrix Failure Considering the Interfacial Debonding Energy." Advanced Materials Research 549 (July 2012): 774–79. http://dx.doi.org/10.4028/www.scientific.net/amr.549.774.

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Considering the interfacial debonding energy at the fiber/matrix interface, an improved Monte Carlo simulation has been done on the matrix failure of the unidirectional ceramic matrix composites. Firstly, the debond length formula was given, then the stress/strain formula was also reviewed, and the matrix failure was simulated by the improved Monte Carlo model, the effect of the interfacial debonding stress on the matrix cracks evolution and the stress/strain curve was considered especially. Lastly, the result was compared to the experiment data. The result shows that the larger interfacial debonding energy at the fiber/matrix interface, the larger debond stress, the crack density increase more slowly, the mean crack density smaller, the final failure strength lower. The improved Monte Carlo simulation result is agreed well with the experiment data.

13

Wang, Jiang, Bin Xu, Qian Liu, Ruiqi Guan, and Xiaoguang Ma. "Feasibility of Stress Wave-Based Debond Defect Detection for RCFSTs Considering the Influence of Randomly Distributed Circular Aggregates with Mesoscale Homogenization Methodology." Materials 16, no. 8 (April 15, 2023): 3120. http://dx.doi.org/10.3390/ma16083120.

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In order to efficiently investigate the effect of the mesoscale heterogeneity of a concrete core and the randomness of circular coarse aggregate distribution on the stress wave propagation procedure and the response of PZT sensors in traditional coupling mesoscale finite element models (CMFEMs), firstly, a mesoscale homogenization approach is introduced to establish coupling homogenization finite element models (CHFEMs) with circular coarse aggregates. CHFEMs of rectangular concrete-filled steel tube (RCFST) members include a surface-mounted piezoelectric lead zirconate titanate (PZT) actuator, PZT sensors at different measurement distances, a concrete core with mesoscale homogeneity. Secondly, the computation efficiency and accuracy of the proposed CHFEMs and the size effect of representative area elements (RAEs) on the stress wave field simulation results are investigated. The stress wave field simulation results indicate that the size of an RAE limitedly affects the stress wave fields. Thirdly, the responses of PZT sensors at different measurement distances of the CHFEMs under both sinusoidal and modulated signals are studied and compared with those of the corresponding CMFEMs. Finally, the effect of the mesoscale heterogeneity of a concrete core and the randomness of circular coarse aggregate distribution on the responses of PZT sensors in the time domain of the CHFEMs with and without debond defects is further investigated. The results show that the mesoscale heterogeneity of a concrete core and randomness of circular coarse aggregate distribution only have a certain influence on the response of PZT sensors that are close to the PZT actuator. Instead, the interface debond defects dominantly affect the response of each PZT sensor regardless of the measurement distance. This finding supports the feasibility of stress wave-based debond detection for RCFSTs where the concrete core is a heterogeneous material.

14

Barrie, Fatmata, David B. Futch, Derek H. D. Hsu, and Michele V. Manuel. "Effect of phase on debond strength in shape memory alloy reinforced composites." Materials & Design 57 (May 2014): 98–102. http://dx.doi.org/10.1016/j.matdes.2013.11.062.

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15

Bin Abdullah, Muhamad Subra, and W. P. Rock. "The Effect of Etch Time and Debond Interval upon the Shear Bond Strength of Metallic Orthodontic Brackets." British Journal of Orthodontics 23, no. 2 (May 1996): 121–24. http://dx.doi.org/10.1179/bjo.23.2.121.

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Groups of orthodontic brackets were attached to enamel after etching for 15, 30 or 60 seconds, they were debonded by shear forces after 5 or 15 minutes, or 24 hours. The 15 seconds etch/5 minutes debond time specimens had much lower shear strengths than other groups. Sixty-second specimens showed evidence of tooth surface damage after tie bonding. Fifteen seconds of etching is therefore recommended routinely for bonding brackets. If a bracket is to be ligated within 5 minutes of placement, 30 seconds etching is recommended. A 60-second etch is considered too severe and should not be used.

16

HU, SHOUFENG, PRASANNA KARPUR, THEODORE E. MATIKAS, LEON SHAW, and NICHOLAS J. PAGANO. "FREE EDGE EFFECT ON RESIDUAL STRESSES AND DEBOND OF A COMPOSITE FIBRE/MATRIX INTERFACE." Mechanics of Composite Materials and Structures 2, no. 3 (September 1995): 215–25. http://dx.doi.org/10.1080/10759419508945841.

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Mall, S., and K. T. Yun. "Effect of Adhesive Ductility on Cyclic Debond Mechanism in Composite-to-Composite Bonded Joints." Journal of Adhesion 23, no. 4 (December 1987): 215–31. http://dx.doi.org/10.1080/00218468708075408.

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Bagwell, Renee M., and Robert C. Wetherhold. "Debond behavior of copper fibers in thermoset matrices and their effect on fracture toughening." Journal of Adhesion Science and Technology 17, no. 16 (January 2003): 2223–42. http://dx.doi.org/10.1163/156856103772150797.

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19

Shang, H. M., E. M. Lim, and K. B. Lim. "Estimation of Size and Depth of Debonds in Laminates From Holographic Interferometry." Journal of Engineering Materials and Technology 114, no. 2 (April 1, 1992): 127–31. http://dx.doi.org/10.1115/1.2904150.

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Double-exposure holography has been shown to be a useful nondestructive testing technique for the detection of debonds in laminates when subjected to vacuum stressing. The size of a debond is estimated from the boundary containing anomalous fringes and subsequently, its depth is estimated from these fringes using a thin-plate model. Rigid-body motion is frequently present during testing, causing ambiguity in the identification of the shape of the debond and hence difficulty in the estimation of its size and depth. In this paper, a simple method is presented which isolates the effects of rigid-body motion so that accurate assessment of the detected debonds can be achieved. Also, the use of a circle to outline the ambiguous boundary is found suitable for square debonds.

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Gentieu, Timothée, Julien Jumel, Anita Catapano, and James Broughton. "Size effect in particle debonding: Comparisons between finite fracture mechanics and cohesive zone model." Journal of Composite Materials 53, no. 14 (December 10, 2018): 1941–54. http://dx.doi.org/10.1177/0021998318816471.

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The present study aims at describing the debonding phenomenon of a particle embedded in an elastic matrix. Two types of fracture mechanics approaches are developed and compared in this context. The phenomenon is analytically described using a finite fracture mechanics approach, while numerical simulations are performed using a cohesive zone model to describe the decohesion process. Both methods rely on two mechanical parameters: the interface strength, σmax and the fracture energy, Gc, of the interface. Both modelling approaches produce results that show larger particles tend to debond before smaller ones although noticeable differences are observed, especially concerning the relationship between the critical load and the particle radius: in the framework of the FFM, the critical load is inversely proportional to the square root of the particle radius, while when using CZM, the critical load is inversely proportional to the particle radius.

21

Song, Hong Tu. "Toughening Mechanism and Mechanical Properties Simulation of Rubber-Toughened Polymers." Key Engineering Materials 723 (December 2016): 68–73. http://dx.doi.org/10.4028/www.scientific.net/kem.723.68.

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When blending rubbers into polymers, different rubber distribution status and fraction due to different mechanical property. In this research, effective mechanical properties of rubber-toughened polymers with four blending fraction in six kinds of particle distribution status are simulated numerically by using finite element method. Rubber particle distribution model include four 2D models and two 3D models. Typical effective mechanical properties such as yield stress, Young's modulus, Poisson's ratio and stress-strain curve of each status are obtained. The Results show that all models Young's modulus and Poisson's ratio decrease with rubber particle volume fraction increasing. Young's modulus and Poisson's ratio of three-dimensional body-centered cubic and face-centered cubic models are in a close magnitude range, it means rubber particle volume fraction has less effect on 2D models and two 3D models. As we all known, Matrix yielding, crazing and interface debond. All play an important role in the toughening process of rubber-toughened polymers. So in this paper we also study on toughening mechanism using same models. Our simulation takes use of stress concentration factor, yield ratio and interface elements' strain difference which is related with matrix yielding, crazing and interface debond to study the toughening mechanism. Simulation shows that the maximum stress concentration factor increases with particle volume fraction. The shear yielding occurs first at the equator of rubber particle, and then yield region expands from the equator to the pole of the particle with loads increasing.

22

Mangalgiri, P. D., W. S. Johnson, and R. A. Everett. "Effect of Adherend Thickness and Mixed Mode Loading on Debond Growth in Adhesively Bonded Composite Joints." Journal of Adhesion 23, no. 4 (December 1987): 263–88. http://dx.doi.org/10.1080/00218468708075410.

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23

Zhuang, Linqi, Andrejs Pupurs, Janis Varna, and Zoubir Ayadi. "Effect of fiber clustering on debond growth energy release rate in UD composites with hexagonal packing." Engineering Fracture Mechanics 161 (August 2016): 76–88. http://dx.doi.org/10.1016/j.engfracmech.2016.04.037.

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Khanna, Puja, Navdeep Kaur, Sunny Mittal, Nishtha Arora, Sumit Chhabra, Harshika Gupta, and Neha Kaswan. "To evaluate the effect of different enamel conditioning procedures on the shear bond strength of new metal bracket on previously debonded tooth surface - An in-vitro study." International Journal of Oral Health Dentistry 9, no. 4 (January 15, 2024): 274–80. http://dx.doi.org/10.18231/j.ijohd.2023.051.

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To evaluate the efficacy of different enamel conditioning methods while bonding a new bracket on a previously de-bonded site, and assess the difference in shear bond strength and ARI score if any. 125 human-extracted premolars were selected. 250 premolar brackets were procured. 125 brackets were bonded on the buccal surface of the premolars using different enamel conditioning methods (bonding sequence 1) and was followed by debonding using the Instron Universal testing machine (Debonding procedure I).The remaining 125 brackets were bonded (Bonding sequence II) on the same teeth after the removal of residual adhesive. Bonding sequence II was followed by debonding (Debonding procedure II), shear bond strength calculation, and ARI score calculation. There was a significant difference in SBS between the 5 groups after initial debonding. SEP group (group 4) showed the highest SBS followed by acid etching groups (groups 3, 2, and 1). The sandblasting group (group 5) had the lowest shear bond strength value. After the second debonding, SBS was found to be highest in Group 3 {37% o-phosphoric acid (Bonding I) sandblasting (Bonding II)} followed by Group 4 {SEP (Bonding I and Bonding II)}, group 2 {acid etching (Bonding I) SEP (Bonding II)}, and group 1 (acid etching in both bonding sequences). Group 5 (sandblasting in both sequences) had the least SBS. Non-significant differences were found in ARI score of the five groups. Self-etching primer group had highest SBS and sandblasting group had least SBS after first debond. The SBS of new brackets after two debonding procedures significantly decreased but was still found to be above the required bond strength. SEP and sandblasting can be used as a substitute to acid etching technique in second time bonding of brackets as these groups had higher SBS after second debond.

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Zheng, Yan Jun, Li Shan Cui, and Jan Schrooten. "Effects of Additional Reinforcing Fibers on the Interface Quality of SMA Wire/Epoxy Composites." Materials Science Forum 475-479 (January 2005): 2047–50. http://dx.doi.org/10.4028/www.scientific.net/msf.475-479.2047.

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There are only limited ways to improve the interface bond strength of SMA wire reinforced composites. In this paper, the effect of the additional reinforcing fibers on the interface debond temperature of a TiNiCu wire reinforced epoxy matrix composite was studied. It was shown that the Kevlar fiber composite had a better interface between the TiNiCu wire and the epoxy matrix than that in the glass fiber composite. The negative thermal expansion coefficient of the Kevlar fibers were thought to be beneficial for relieving the thermal stresses at the SMA/epoxy interface. From this angle of view, the Kevlar fiber composites are better candidates as the matrix of the SMA composites than the glass fiber composites.

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Levy, A. J. "The Fiber Composite With Nonlinear Interface—Part I: Axial Tension." Journal of Applied Mechanics 67, no. 4 (June 25, 2000): 727–32. http://dx.doi.org/10.1115/1.1329319.

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This paper treats the effective axial tension response of a composite consisting of fibers that debond from the matrix according to nonlinear Needleman-type cohesive zones. A second, related paper (Part II) treats effective antiplane shear response. The composite cylinders representation of a representative volume element (RVE) is employed throughout. For axial tension loading a simple rotationally symmetric boundary value problem for a single composite cylinder is solved. Bounds on the total potential energy and the total complementary energy are shown to coincide and an exact solution for axial extension and Poisson contraction of an RVE of the composite is obtained. Nonlinear interfacial debonding, however, is shown to have a negligible effect on extensional response and only a small, though potentially destabilizing, effect on Poisson contraction response. [S0021-8936(00)02004-3]

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Dève, H. E., and S. Schmauder. "Role of interface properties on the toughness of brittle matrix composites reinforced with ductile fibers." Journal of Materials Research 7, no. 11 (November 1992): 3132–38. http://dx.doi.org/10.1557/jmr.1992.3132.

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The incorporation of ductile fibers in brittle matrices can lead to a significant increase in fracture resistance. The increase in toughness that derives from crack bridging is governed by the properties of the matrix/fiber interface and the ductility of the fibers. The current study addresses the role of interface sliding stress on the toughness of brittle composites reinforced with ductile fibers. The debond length is explicitly related to the interface sliding stress and the properties of the fiber. It is then incorporated into a geometrical model to simulate the bridging tractions versus crack opening under condition of continuous debonding. The implications on the effect of interfaces on the resistance curve are discussed.

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Mahesh, C., K. Govindarajulu, and V. Balakrishna Murthy. "Homogenization of partial debond effect on the effective thermal conductivities of FRP composite using finite element analysis." Composite Interfaces 22, no. 1 (December 13, 2014): 51–65. http://dx.doi.org/10.1080/15685543.2015.985957.

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Mishima, Fernanda D., Raquel Gomes A. Valentim, Monica Tirre S. Araújo, Antonio Carlos O. Ruellas, and Eduardo F. Sant’Anna. "The effect of tooth bleaching on the enamel surface and the tensile force to debond orthodontic brackets." Journal of Orthodontics 36, no. 4 (December 2009): 236–42. http://dx.doi.org/10.1179/14653120723265.

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Mahesh, C., K. Govindarajulu, and V. Balakrishna Murthy. "Simulation-based verification of homogenization approach in predicting effective thermal conductivities of wavy orthotropic fiber composite." International Journal of Computational Materials Science and Engineering 08, no. 04 (September 24, 2019): 1950015. http://dx.doi.org/10.1142/s2047684119500155.

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In this work, applicability of homogenization approach is verified with the micromechanics approach by considering wavy orthotropic fiber composite. Thermal conductivities of [Formula: see text]-300 orthotropic wavy fiber composite are determined for micromechanical model and compared with the results obtained by two stage homogenized model over volume fraction ranging from 0.1 to 0.6. Also, a methodology is suggested for reducing percentage deviation between homogenization and micromechanical approaches. Effect of debond on the thermal conductivities of wavy orthotrophic fiber composite is studied and compared with perfectly aligned fiber composite for different volume fraction. It is observed that results obtained by the homogenization approach are in good agreement with the results obtained through micromechanics approach. Maximum percentage deviation between homogenized and micromechanics models is 2.13%.

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Tiryakioğlu, Murat. "Intrinsic and Extrinsic Effects of Microstructure on Properties in Cast Al Alloys." Materials 13, no. 9 (April 25, 2020): 2019. http://dx.doi.org/10.3390/ma13092019.

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The metallurgy of cast aluminum alloys has always been considered to be different from that of wrought alloys. Metallurgists have been taught that pores are intrinsic in cast aluminum alloys and that mechanical properties in cast aluminum alloys are controlled by dendrite arm spacing, the presence of Fe-bearing particles, and the size of Si particles in Al–Si alloys, which fracture and debond during deformation, leading to premature failure. Whether these effects are intrinsic or extrinsic, i.e., mere correlations due to the structural quality of castings, is discussed in detail. Ideal properties are discussed, based on findings presented mostly in physics literature. Pores and hot tears in aluminum castings are extrinsic. Moreover, the effect of dendrite arm spacing on elongation, precipitation, and subsequent fracture of β–Al5FeSi platelets, and finally Si particle fracture and debonding are all extrinsic. A fundamental change in how we approach the metallurgy of cast aluminum alloys is necessary.

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Hohlfelder, Robert J., Daniel A. Maidenberg, Reinhold H. Dauskardt, Yueguang Wei, and W. Hutchinson. "Adhesion of benzocyclobutene-passivated silicon in epoxy layered structures." Journal of Materials Research 16, no. 1 (January 2001): 243–55. http://dx.doi.org/10.1557/jmr.2001.0037.

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Adhesion and subcritical debonding at interfaces between a silica-filled epoxy underfill and a silicon die passivated by silicon nitride and benzocyclobutene (BCB) layers were investigated. Adhesion was measured in terms of a critical value of the applied strain energy release rate, G (J/m2 ). Subcritical debond-growth rates in the range of 10−9 to 10−3 m/s were characterized as a function of applied G. Adhesion and subcritical debonding were affected by changes in interfacial chemistry and environment. The surprisingly large effect of adjacent layer elastic properties on interfacial adhesion was demonstrated with simulations of interfacial fracture using a mechanics of materials approach. Interfacial chemistry was modified by using different adhesion promoters, by varying the BCB cure state, and by using different epoxy underfill resins. The effects of environmental variables were studied with temperature- and humidity-controlled environments in order to determine the separate roles of moisture activity and temperature.

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Sfondrini, Maria Francesca, Danilo Fraticelli, Paola Gandini, and Andrea Scribante. "Shear Bond Strength of Orthodontic Brackets and Disinclusion Buttons: Effect of Water and Saliva Contamination." BioMed Research International 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/180137.

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Purpose. The aim of this study was to assess the effect of water and saliva contamination on the shear bond strength and failure site of orthodontic brackets and lingual buttons.Materials and Methods. 120 bovine permanent mandibular incisors were randomly divided into 6 groups of 20 specimens each. Both orthodontic brackets and disinclusion buttons were tested under three different enamel surface conditions: (a) dry, (b) water contamination, and (c) saliva contamination. Brackets and buttons were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bond strength values and adhesive failure rate were recorded. Statistical analysis was performed using ANOVA and Tukey tests (strength values) and Chi squared test (ARI Scores).Results. Noncontaminated enamel surfaces showed the highest bond strengths for both brackets and buttons. Under water and saliva contamination orthodontic brackets groups showed significantly lower shear strengths than disinclusion buttons groups. Significant differences in debond locations were found among the groups under the various enamel surface conditions.Conclusions. Water and saliva contamination of enamel during the bonding procedure lowers bond strength values, more with orthodontic brackets than with disinclusion buttons.

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Sun, Chao, Nannan Lu, Huan Liu, Xiaojun Wang, Xiaoshi Hu, and Deqiang Chen. "Effect of Necklace-Type Distribution of SiC Particles on Dry Sliding Wear Behavior of As-Cast AZ91D/SiCp Composites." Crystals 10, no. 4 (April 13, 2020): 296. http://dx.doi.org/10.3390/cryst10040296.

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In this study, the dry sliding wear behaviors of SiC particle reinforced AZ91D matrix composites fabricated by stirring casting method were systematically investigated. The SiC particles in as-cast composites exhibited typical necklace-type distribution, which caused the weak interface bonding between SiC particles and matrix in particle-segregated zones. During dry sliding at higher applied loads, SiC particles were easy to debond from the matrix, which accelerated the wear rates of the composites. While at the lower load of 10 N, the presence of SiC particles improved the wear resistance. Moreover, the necklace-type distribution became more evident with the decrease of particle sizes and the increase of SiC volume fractions. Larger particles had better interface bonding with the matrix, which could delay the transition of wear mechanism from oxidation to delamination. Therefore, composites reinforced by larger SiC particles exhibited higher wear resistance. Similarly, owing to more weak interfaces in the composites with high content of SiC particles, more severe delamination occurred and the wear resistance of the composites was impaired.

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Rossettos, J. N., P. Lin, and H. Nayeb-Hashemi. "Comparison of the Effects of Debonds and Voids in Adhesive Joints." Journal of Engineering Materials and Technology 116, no. 4 (October 1, 1994): 533–38. http://dx.doi.org/10.1115/1.2904324.

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An analytical model is developed to compare the effects of voids and debonds on the interfacial shear stresses between the adherends and the adhesive in simple lap joints. Since the adhesive material above the debond may undergo some extension (either due to applied load or thermal expansion or both), a modified shear lag model, where the adhesive can take on extensional as well as shear deformation, is used in the analysis. The adherends take on only axial loads and act as membranes. Two coupled nondimensional differential equations are derived, and in general, five parameters govern the stress distribution in the overlap region. As expected, the major differences between the debond and the void occur for the stresses near the edge of the defect itself. Whether the defect is a debond or a void, is hardly discernible by the stresses at the overlap ends for central defect sizes up to the order of 70 percent of the overlap region. If the defect occurs precisely at or very close to either end of the overlap, however, differences of the order of 20 percent in the peak stresses can be obtained.

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Armanios, EA, RB Bucinell, DW Wilson, KA Lubke, LM Butkus, and WS Johnson. "Effect of Environment on Fracture Toughness and Debond Growth of Aluminum/FM®73/Boron-Epoxy Adhesively Bonded Joints." Journal of Composites Technology and Research 23, no. 1 (2001): 42. http://dx.doi.org/10.1520/ctr10912j.

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Majumdar, Prasun, Deepak Srinivasagupta, Hassan Mahfuz, Babu Joseph, Matthew M. Thomas, and Stephen Christensen. "Effect of processing conditions and material properties on the debond fracture toughness of foam-core sandwich composites: experimental optimization." Composites Part A: Applied Science and Manufacturing 34, no. 11 (November 2003): 1097–104. http://dx.doi.org/10.1016/s1359-835x(03)00207-0.

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Monetto, Ilaria. "The Effects of an Interlayer Debond on the Flexural Behavior of Three-Layer Beams." Coatings 9, no. 4 (April 17, 2019): 258. http://dx.doi.org/10.3390/coatings9040258.

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Debonds at the interfaces between layers of multilayered systems make the degree of the composite action reduce. As a consequence, the global stiffness of such composites decreases. In order to investigate this reduction, even simplified analytical models are preferable to numerical analyses. This paper analyzes the flexural response of a three-point bending three-layer beam having a debonded portion at the upper interface to investigate the effects of the interlayer debond on the flexural stiffness of the three-layer beam and to examine the feasibility of detecting the presence of possible manufacturing or in-service flaws. A more general model proposed and validated previously by the author was specialized to solve the equilibrium problem considered. A parametric analysis was then performed on varying the model parameters and evaluating the maximum deflection to compare with that for perfectly bonded layers as a measure of the reduction of the flexural stiffness due to the presence of the debond. The numerical results obtained show that the flexural behavior of the sandwich beam under consideration is affected strongly by the length of the debond but only moderately by its position along the interface unless the outer faces are quite stiffer than the core.

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Srinivasagupta, Deepak, Babu Joseph, Prasun Majumdar, and Hassan Mahfuz. "Effect of processing conditions and material properties on the debond fracture toughness of foam-core sandwich composites: process model development." Composites Part A: Applied Science and Manufacturing 34, no. 11 (November 2003): 1085–95. http://dx.doi.org/10.1016/s1359-835x(03)00200-8.

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Bahnasi, FI, NM Abdullah, and MIA Hassan. "Shear Bond Strength of Orthodontic Brackets Bonded with Different Curing Methods." Compendium of Oral Science 1, no. 1 (September 1, 2014): 25–31. http://dx.doi.org/10.24191/cos.v1i0.17531.

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Objectives: To evaluate the effect of light-cure devices and curing times on the shear bond strength (SBS) of orthodontic brackets. Material and Methods: 60-extracted human premolars were divided into 6-groups of 10-teeth each and bonded with stainless-steel brackets by using 3M Unitek Transbond XT composite. Specimens were cured with halogen, LED and plasma arc lights with two different times for each. The specimens were subjected to shear force till debond with a crosshead speed of 1mm/min and tested after 5min. The stress was calculated and data were subjected to statistical analysis. Results: one-way ANOVA and Dunnett T3 post hoc comparison test were used. There were no significant differences between the 6 groups (p < 0.05). Conclusions: all curing light methods with loading force after 5 min achieved SBS more than the normal range; therefore, arch wire can be inserted at the same visit using any of tested curing light device or curing time.

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Chiang, Y. C. "Mechanics of Matrix Cracking in Bonded Composites." Journal of Mechanics 23, no. 2 (June 2007): 95–106. http://dx.doi.org/10.1017/s172771910000112x.

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AbstractIn this paper, a general matrix cracking model including the effect of fiber/matrix debonding in the crack wake is developed for a unidirectional fiber reinforced composite. The debonding mechanics is incorporated into matrix cracking model by treating the crack-wake debonding as a particular crack propagation problem along the interface. Then, the closed-form analytical solution of the critical stress for the onset of widespread matrix cracking is derived, based on the analysis of steady state crack growth in the matrix. The fracture mechanics approach adopted in the present analysis is compared with the analysis in which the crack-wake debonding mechanics was modeled by energy balance approach. The conditions for attaining no-debonding and debonding as onset of widespread matrix cracking are discussed in terms of the interfacial properties of debond toughness and frictional shear stress. The theoretical results are compared with experimental data that are available in the literature.

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Ali, Zain, Jakob Schmidt, Jörg Kaufmann, and Holger Cebulla. "Influence of nonwoven interleave layer on interlaminar fracture of sandwich-structured composites." Technologies for Lightweight Structures (TLS) 5, no. 1 (March 28, 2022): 86–94. http://dx.doi.org/10.21935/tls.v5i1.153.

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Debonding between the skins and the core is one of the critical failure modes encountered by sandwich-structured composites in highly strained conditions. The onset and growth of a debond critically hinder the load-bearing capacity of the sandwich structure. This paper investigates the effect on the debonding resistance of a sandwich-structured composite by the addition of nonwoven flax interleave veil in the skin-core interface. Mode-II fracture toughness is estimated through a proposed method based on curve fitting of numerical data to experimental results. Experimental data are obtained in a four-point bending test following the standard DIN 53 293 and Cohesive Zone Modelling (CZM) is implemented as the numerical tool in the analysis of Mode-II skin-core debonding. A series of sandwich specimens are fabricated using twill weave e-glass fabric and expanded polystyrene core with and without the addition of an interleave layer. Numerical data show a 60 % increment in Mode-II fracture toughness with the inclusion of a flax interleaf layer. Microscopic images attribute the increment to the presence of fibre bridging effect. The proposed method produces a good fit of numerical data to experimental results.

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Selvam, Vignesh, Vijay Shankar Sridharan, and Sridhar Idapalapati. "Static and Fatigue Debond Resistance between the Composite Facesheet and Al Cores under Mode-1 in Sandwich Beams." Journal of Composites Science 6, no. 2 (February 7, 2022): 51. http://dx.doi.org/10.3390/jcs6020051.

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The debonding toughness between unidirectional glass fiber reinforced polymer face sheets and cellularic cores of sandwich structures is experimentally measured under static and fatigue loading conditions. The effect of various core geometries, such as regular honeycomb and closed-cell foams of two relative densities on the adhesive interfacial toughness is explored using the single cantilever beam (SCB) testing method. The steady-state crack growth measurements are used to plot the Paris curves. The uniformity of adhesive filleting and the crack path was found to affect the interfacial toughness. The static Mode-1 interfacial toughness of high-density foam cores was witnessed to be maximal, followed by low-density honeycomb, high-density honeycomb, and low-density foam core. Similarly, the fatigue behavior of the low-density honeycomb core has the lowest crack growth rates compared to the other samples, primarily due to uniform adhesive filleting.

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Li, Cheng-Di, Bin Li, Yan Shen, Mei Jin, and Jiu-Jun Xu. "Effect of surface chemical etching on the lubricated reciprocating wear of honed Al–Si alloy." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 232, no. 6 (September 1, 2017): 722–31. http://dx.doi.org/10.1177/1350650117727213.

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To improve the wear resistance of the honed Al–Si alloy cylinder liner, the chemical etching was applied on the surface of the Al–Si alloy samples. The effect of the etching time on the wear behaviors of the etched surface was investigated using an in-house designed reciprocating wear machine with oil lubrication. Meanwhile, the tribological properties were related to the changes in the surface morphology of the Al–Si alloy samples before and after the wear tests to analyze the associated underlying wear mechanisms. Results show that 5% NaOH solution is an effective chemical agent to etch the surface of Al–Si alloy samples. The 2 min etched Al–Si alloy samples exhibits low friction coefficient and small weight loss, indicating a good wear behavior of the properly etched surface. The insufficiently etched surface was found when the etching time was less than 2 min. Rare silicon particles are exposed due to the little removal of the aluminum on the surface, such that aluminum will be in direct contact with the piston ring during friction, causing adhesive wear. In contrast, overetching leads to the even more seriously worn out surface as observed in the samples etched for more than 3 min. The silicon particles tends to debond from the matrix with the increase of etching depth, then serve as the abrasive grains in the friction, resulting in the considerable increase of the friction coefficient and weight loss.

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Islam, Md Shahidul, and Hideo Koguchi. "Investigation of Order of Singularity in 3D Transversely Isotropic Piezoelectric Bimaterial Joints by FEM." Journal of Circuits, Systems and Computers 24, no. 02 (November 27, 2014): 1540001. http://dx.doi.org/10.1142/s0218126615400010.

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The order of singularity near the vertex of bonded joints is one of the main factors responsible for debonding of electronic device under mechanical or electrical loading. The distribution of singularity field near the vertex of bonded joints is very important to maintain the reliability of smart electronic structure. Piezoelectric material, due to its characteristic direct-converse piezoelectric effect, has naturally received considerable attentions. Piezoelectric materials have been extensively used as transducers and sensors due to their piezoelectric effects that take place between electric fields and mechanical deformation. The order of singularity at a vertex and at a point on singularity line in 3D transversely isotropic piezoelectric joints is analyzed. Eigen analysis based on FEM is used for stress singularity field analysis of piezoelectric bimaterial joints. The eigen equation is used for calculating the order of stress singularity and the angular function of elastic displacement, electric potential, stress and electric displacement. The numerical result shows that the angular functions have large value near the interface edge than the inner portion of the joint. Therefore, there is a possibility to debond and delamination occurs at interface edge of the piezoelectric bimaterial joints, due to the higher stress and electric displacement concentration at the free edge.

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Kook, S. Y., J. M. Snodgrass, A. Kirtikar, and R. H. Dauskardt. "Adhesion and Reliability of Polymer/Inorganic Interfaces." Journal of Electronic Packaging 120, no. 4 (December 1, 1998): 328–35. http://dx.doi.org/10.1115/1.2792642.

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The reliability of microelectronic components is profoundly influenced by the interfacial fracture resistance (adhesion) and associated progressive debonding behavior. In this study we examine the interfacial fracture properties of representative polymer interfaces commonly found in microelectronic applications. Specifically, interface fracture mechanics techniques are described to characterize adhesion and progressive bebonding behavior of a polymer/metal interface under monotonic and cyclic fatigue loading conditions. Cyclic fatigue debond-growth rates were measured from ~10−11 to 10−6 m/cycle and found to display a power–law dependence on the applied strain energy release rate range, ΔG. Fracture toughness test results show that the interfaces typically exhibit resistance-curve behavior, with a plateau interface fracture resistance, Gss, strongly dependent on the interface morphology and the thickness of the polymer layer. The effect of a chemical adhesion promoter on the fracture energy of a polymer/silicon interface was also characterized. Micromechanisms controlling interfacial adhesion and progressive debonding are discussed in terms of the prevailing deformation mechanisms and related to interface structure and morphology.

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NguyenDinh, Nen. "Interface horizontal shear strength requirement in Ultra-thin whitetopping (UTW) pavement." IOP Conference Series: Materials Science and Engineering 1289, no. 1 (August 1, 2023): 012062. http://dx.doi.org/10.1088/1757-899x/1289/1/012062.

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Abstract Ultra-thin whitetopping (UTW) is a thin (5-10 cm) layer of concrete overlaying over an existing asphalt pavement. This concrete layer is bonded on the asphalt surface. Although UTW has been successful in strengthening asphalt pavement, in some cases, the composite pavement may debond at the interface under the concrete slab due to high shear stress. This paper aims to determine the interface shear strength required for UTW pavement systems using theoretical methods and calibrated numerical models (FEMs). The study analysed 432 pavement scenarios with different slab sizes, thicknesses, and material properties. The results show that higher shear stress occurs when the asphalt modulus is stiffer. The size of the slab, the modulus of the supporting layer, and the asphalt thickness have only a minor effect on the shear stress value. However, the thickness of the concrete slab significantly affects the maximum shear stress in the UTW, with an increase of up to 36.6% when reducing the slab thickness from 100mm to 50 mm. The FEM calculations can be used to determine the required interface horizontal shear strength for UTW.

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Ševeček, Oldřich, Michal Kotoul, and Tomáš Profant. "Effect of higher order asymptotic terms on the competition between crack penetration and debond at a bimaterial interface between aligned orthotropic materials." Engineering Fracture Mechanics 80 (January 2012): 28–51. http://dx.doi.org/10.1016/j.engfracmech.2011.11.006.

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Juntavee, Patrapan, Hattanas Kumchai, Niwut Juntavee, and Dan Nathanson. "Effect of Ceramic Surface Treatment and Adhesive Systems on Bond Strength of Metallic Brackets." International Journal of Dentistry 2020 (May 25, 2020): 1–8. http://dx.doi.org/10.1155/2020/7286528.

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Objective. This study evaluated the effect of ceramic surface treatments on bond strength of metal brackets to machinable ceramics and veneering porcelain using different adhesive resins. Materials and methods. Machined ceramic specimens (10 × 10 × 2 mm) were prepared from Vitablocs mark II (Vita) and IPS e.max® CAD (Ivoclar). Layered porcelain fused to metal (IPS d.Sign®, Ivoclar) was used to fabricate PFM specimens (n = 60/group). Half of specimens were etched (9.6% HF, 15 sec), and the rest were nonetched. Three resin bonding systems were used for attaching metal brackets (Victory series™ APC II, 3M) to each group (n = 10): Transbond™ XT (3M), Light Bond™ (Reliance), or Blugloo™ (Ormco), all cured with LED curing unit (Bluephase G1600, Vivadent) for 50 s each. Specimens were immersed in deionized water at 37°C for 24 hours prior to shear bond testing (Instron) at crosshead speed of 0.5 mm/min. Debond surface of ceramic and bracket base was examined for failure mode (FM), Ceramic Damage Index (CDI), and Adhesive Remnant Index (ARI). ANOVA and post hoc multiple comparisons were used to analyze the differences in bond strength. The chi-squared test was used to determine significance effect of FM, CDI, and ARI. Results. Significant differences in shear bond strength among group were found (p≤0.05) related to ceramic, surface treatment, and resin cement. Conclusion. Bond strength of bracket to ceramic is affected by type of ceramic, resin cement, and ceramic surface conditioning. Etching ceramic surface enhanced ceramic-bracket bond strength. However, bond strengths in nontreated ceramic surface groups were still higher than bond strength required for bonding in orthodontic treatment.

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Jayaram, R. S., V. A. Nagarajan, and K. P. Vinod Kumar. "Mechanical performance of polyester pin-reinforced foam filled honeycomb sandwich panels." Science and Engineering of Composite Materials 25, no. 4 (July 26, 2018): 797–805. http://dx.doi.org/10.1515/secm-2017-0039.

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Abstract Honeycomb sandwich panels entice continuously enhanced attention due to its excellent mechanical properties and multi-functional applications. However, the principal problem of sandwich panels is failure by face/core debond. Novel lightweight sandwich panels with hybrid core made of honeycomb, foam and through-thickness pin was developed. Reinforcing polyester pins between faces and core is an effectual way to strengthen the core and enhance the interfacial strength between the face/core to improve the structural performance of sandwich panels. To provide feasibility for pin reinforcement, honeycomb core was pre-filled with foam. Mechanical properties enhancement due to polyester pinning were investigated experimentally under flatwise compression, edgewise compression and flexural test. The experimental investigations were carried out for both “foam filled honeycomb sandwich panels” (FHS) and “polyester pin-reinforced foam filled honeycomb sandwich panels” (PFHS). The results show that polyester pin reinforcement in foam filled honeycomb sandwich panel enhanced the flatwise, edgewise compression and flexural properties considerably. Moreover, increasing the pin diameter has a larger effect on the flexural rigidity of PFHS panels. PFHS panels have inconsequential increase in weight but appreciably improved their structural performance.

Journal articles on the topic 'Debond effect'

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