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Resonance bond testing is a nondestructive testing (NDT) technique that is used to detect disbonds, delaminations, and other voids in composite materials. The aerospace industry has seen an increase in the use of carbon fiber reinforced plastics (CFRP) for aircraft and spacecraft construction. Composite materials offer many advantages over traditional metallic structures, which include weight savings, increased strength, design for specific load paths, and the ability to easily construct geometrically complex structures. Resonance bond testing has many established uses for metallic structures as well, such as aluminum skin-to-skin and skin-to-core bonds. This bond testing technique has been around for many decades but is used by only a small portion of the NDT community. Ultrasonic testing (UT), specifically phased array ultrasonic testing (PAUT), using linear array techniques has proven to be a reliable method for the inspection of CFRP laminates. When composite structures do not permit the use of high-frequency sound waves due to rapid attenuation, resonance bond testing is a proven alternative. In this paper, the authors will discuss the theory behind resonance bond testing and how it has and continues to play an important role in the NDT industry.

Through Silicon Vias (TSVs) are crucial elements for the reliable operation and yield of three dimensional integrated circuits (3D ICs). Defects are a serious concern in TSV structures. A post-bond, parallel testing and diagnosis scheme is proposed in this work, for the detection and location of resistive open or short to substrate defects in TSVs, which is based on easily synthesizable all digital testing circuitry. The new testing method provides tolerance over process and temperature variations that may influence the embedded circuits. Extensive typical model simulations and Monte-Carlo analysis results, using the 65 nm technology of TSMC, prove the effectiveness of the new method. Additionally, two representative methods from the literature are simulated and compared to the proposed one, in terms of effectiveness, robustness, tolerance, cost and design for testability effort. The proposed scheme is proven to perform better based on all presented criteria.

Summary: Microtensile bond strength (μTBS) test was introduced in 1994. Since then, it has been utilized profoundly across many bond strength testing laboratories, making it currently one of the most standard and versatile bond strength test. Although it is a static and strength-based method, together with the morphological and spectroscopic investigations, it has been contributing immensely in the advancement of dentin adhesive systems. μTBS test has a greater discriminative capability than the traditional macro-shear bond test. During the early stage of its development, the authors predicted that this testing method would enable evaluation of the adhesive performances of resins to excavated carious or sclerotic dentin and the regional bond strengths of various portions of the cavity. In addition, they also stated the possibility of comparing the long-term stability of resin adhesion at various portions of the cavity walls on teeth extracted at various times after insertion of bonded restorations. In this review, we discussed the historical background, inception and the application of the μTBS test and proposed directions for further improvement of this testing method.

Zahavi's "Bond Testing Hypothesis" states that irritating stimuli are used to elicit honest information from social partners regarding their attitudes towards the relationship. Two elements of the Cebus capucinus vocal repertoire, the "gargle" and "twargle," have been hypothesized to serve such a bond-testing function. The greatest threat to C. capucinus infant survival, and to adult female reproductive success, is infanticide perpetrated by alpha males. Thus, we predicted that infants (

Glubam (glued-laminated bamboo) is a newly developed structural material with properties comparable to other wood and wood-based materials. Fiber-reinforced polymer (FRP) bar is an attract...

Interlayer bond strength is one of the key aspects of 3D concrete printing. It is a well-established fact that, similar to other 3D printing process material designs, process parameters and printing environment can significantly affect the bond strength between layers of 3D printed concrete. The first section of this review paper highlights the importance of bond strength, which can affect the mechanical and durability properties of 3D printed structures. The next section summarizes all the testing and bond strength measurement methods adopted in the literature, including mechanical and microstructure characterization. Finally, the last two sections focus on the influence of critical parameters on bond strength and different strategies employed in the literature for improving the strength via strengthening mechanical interlocking in the layers and tailoring surface as well as interface reactions. This concise review work will provide a holistic perspective on the current state of the art of interlayer bond strength in 3D concrete printing process.

The possibility of 3D integrated circuit (3D IC) has been considered as a choice to overcome the difficulties faced by two-dimensional integrated circuits (2D IC). Several technologies exist to connect the layers in 3D IC. Among these technologies through-silicon vias (TSVs) is the promising one since it helps to reduce interconnect length, delays and power consumption. In spite of the advantages it introduces different types of defects which ultimately make an entire IC faulty. Thus, testing of TSVs is an important necessity. Depending on the timing, the testing may be of two types -pre-bond and post-bond. In pre-bond TSV testing TSVs are tested in sessions. In this paper our objective is to reduce the pre-bond TSV test sessions as much as possible, so that overall testing time decreases. To reduce test sessions we need to reduce the individual TSV testing and increase group wise TSV testing.

To compare the microshear bond strength of resin based composite (RBC) and resin modified glass ionomer cement (RMGIC) restorations when bonded to teeth with molar incisor hypomineralisation (MIH). Eleven first permanent molars with MIH were included in this study. Teeth were sectioned mesio-distally producing a total of 22 surfaces for testing. Each specimen was placed inside a plastic ring with the flattened surface in contact with a glass slab. The plastic ring was filled with autopolymerising acrylic resin to imbed the specimen leaving the enamel surface exposed. Each surface was then bonded to 0.96 mm diameter RBC and light cured RMGIC following the manufacturers’ instructions. Microshear bond testing was performed after 24 h storage in distilled water at 37 °C. A Bisco shear tester was used to apply shear stress of 1 mm/min until failure. Wilcoxon signed-rank paired-test was used for comparison of bond strength values. Microshear bond strength of RBC (30.80 ± 8.19 MPa) was significantly higher than that of RMGIC (11.13 ± 6.91 MPa) when bonded to hypomineralised permanent first molars (p

Background: The rapid developments in the field of adhesive dental materials have led to improvements in many aspects of clinical dentistry. Adhesive bond strength plays an important role in determining the clinical performance and longevity of dental restorations. Nevertheless, bond strength tests have never been well-standardized, although a number of important recommendations have been made. Objective: The aim of this paper is to critically review the validity of different bond strength testing methods for assessment of bonding effectiveness of adhesive materials to tooth structure and discuss factors that may affect bond strength measurement. Data Collection: Relevant literature published between 1983 and 2018 was collected and reviewed from the PubMed database and Google scholar resources. Review Results: Results of the current bond testing methods should be used to compare materials tested under the same laboratory settings, but they shouldn’t be used to make direct inferences on their clinical behaviour. Shear and micro-shear tests, result in non-uniform stress distribution, stress concentration at the substrate area, and predominantly tensile stresses rather than shear stresses. Micro-tensile bond tests provide many advantages over the shear tests, although these methods are technique sensitive and labour intensive. Conclusion: Bond strength testing methods should be well-standardized, but there are many factors that cannot be fully controlled which leads to variation and misinterpretation of the data about the bonding abilities of adhesives. Clinical Significance: New adhesive materials should be subjected to a combination of testing protocols to properly assess their bonding effectiveness.

Objective: This study aimed to evaluate the effect of the application of sodium metabisulfite (SMB) on the bond strength of bleached teeth. Materials and Methods: The study was divided into two parts. The first part evaluated the application of various concentrations of SMB for 1 h prior to the completion of bonding procedures. Fifty blocks were divided into five groups (n = 10): control; bleaching with 35% hydrogen peroxide (HP); HP + 5% SMB; HP + 12.5% SMB; and HP + 25% SMB. The second part evaluated the application of 25% gel SMB to either enamel or dentin, including the application time. Sixty blocks were divided into six groups (n = 10): control; bleaching with 35% HP; HP + 25% SMB for 1 h in enamel; HP + 25% SMB for 1 h in dentin; HP + 25% SMB for 10 min in enamel; and HP + 25% SMB for 10 min in dentin. Statistical Analysis: Following the completion of microshear bond testing, data were analyzed using one-way analysis of variance as well as Tukey's and Dunnett's tests. Results: In part 1, data analysis revealed statistical differences (P < 0.0001) between HP and HP + 5% SMB. No statistical differences were found between the control and both HP + 12.5% SMB and HP + 25% SMB. Part 2 revealed a statistical difference (P = 0.001359) only between the bleached group and others. Conclusions: The use of 25% SMB gel immediately after bleaching was able to reverse the deleterious effect of bleaching on the bond strength of dental composites to dentin.

Fabric-reinforced cementitious matrix (FRCM) composites consist of a dry fiber fabric embedded in an inorganic mortar that may be enriched with short fibers. These composites are particular...

Nondestructive testing and evaluation (NDT&E) of materials and structures is important for many civil and infrastructure applications. To this end, this paper introduces active microwave thermography (AMT) as a real-time monitoring tool for detection of defect formation and propagation in composite-strengthened concrete structures. AMT is a thermographic NDT&E technique which utilizes microwave radiation as a heat source. In this case, AMT is used to detect and evaluate debonding in a number of concrete specimens which have been strengthened with externally bonded carbon-fiber-reinforced polymer (CFRP) composite. As microwave radiation can be constantly and continuously applied over a long period of time, it can be effectively used as a source of thermal energy for long inspections. Several measurement results are presented in the paper that support AMT as a successful monitoring tool for the aforementioned application.

The yield of 3D stacked IC manufacturing improves with the pre-bond integrity testing of through silicon vias (TSVs). In this paper, an efficient pre-bond test method is presented based on IEEE std. 1500, which can precisely diagnose any happening of TSV defects. The IEEE std. 1500 wrapper cells are augmented for the proposed method. The pre-bond TSV test can be performed by adjusting the driving strength of TSV drivers and the test clock frequency. The experimental results show the advantages of the proposed approach.

In order to obtain acceptable compound stack yields for 2.5D‐ and 3D‐stacked integrated circuits (SICs), there is a need to test the constituting dies before stacking. The non‐bottom dies of these stacks have their functional access exclusively through large arrays of fine‐pitch micro‐bumps, which are too dense for conventional probe technology. A common approach to obtain pre‐bond test access is to equip these dies with dedicated pre‐bond probe pads, which comes with drawbacks such as increased silicon area and test application time and reduced interconnect performance. In order to avoid the many drawbacks of dedicated pre‐bond probe pads, we advocate the usage of advanced probe technology that allows to directly probe on these micro‐bumps. This chapter reports on the technical feasibility of this approach. The economical feasibility is addressed in Chapter 9.

International audience; The following recommendations are based on the chapter III of a State of the Art review conducted by the Task Group 2 of the RILEM Technical Committee 241-MCD 'Mechanisms of cracking and debonding in asphalt and composite pavements' (Petit et al in Mechanisms of cracking and debonding in asphalt and composite pavements. Chapter III of the State-of-the-Art report of the RILEM technical committee 241-MCD series, vol 28. Springer, New York, pp 103-154. ISBN 978-3-319-76848-9 2018). The recommendations mostly concern 'pure' fracture mode test methods that are currently used worldwide and even standardized, while mixed mode test methods developed by few research teams have not received full attention. This paper intends to give guidance for the application and characterization of interlayer bond testing, looking at the appropriate test methods and the importance of influencing parameters.

Pre-bond testing of through silicon vias (TSVs) in 3D ICs is very challenging task. Reliability and correctness of 3D ICs consisting of numbers of TSVs have to be established. This paper presents an innovative pre-bond test method for TSVs in a 3D IC. The logic is devised around the cascadable arrangement of Cellular Automata (CA), discovered by von Neumann in the year of 1960. SACA, a designated class of CA, has been developed to diagnose conductor and insulator defects in TSVs. The segmentation of CA in the design assures more effectiveness, with respect to the number of computations to identify faulty TSVs. The implemented hardware realizes quick test of manufacturing TSV faults in the pre-bond phase.

Purpose The aim of this study was to evaluate the microtensile bond strength of three computer-aided design/computer-aided manufacturing (CAD/CAM) blocks repaired with composite resin using three surface treatment techniques. Methods and Materials Three different CAD/CAM blocks were used in this study: (1) Lithium disilicate, (2) feldspar ceramic, and (3) resin nano ceramic. All groups were further divided into four subgroups according to surface treatment: control, roughened with bur (B); roughened with bur and 5% Hydrofluoric acid (HF); roughened with bur and sandblasting (HF); and roughened with bur and CoJet (C). After surface treatments on each group, a silane and bonding agent were applied, and ceramics were repaired with a nano-hybrid composite. Then, the repaired ceramics were cut with a low-speed diamond saw for microtensile bond testing. Microtensile bond tests for 40 specimens per subgroup were carried out with a universal testing machine. The data were analyzed with ANOVA, Tukey's, and LSD at the 95% significance level. Results Mean bond strengths (MPa) of subgroups B, HF, S, and C were: 0, 29.8, 0, 23.3 for lithium disilicate ceramic; 26.4, 22.3, 22.4, 22 for feldspar ceramic; 54.8, 25.3, 42.1, 25.7 for resin nano ceramic. For subgroups B and S of lithium disilicate ceramics, bonding failed during specimen preparation. No significant differences were observed among all CoJet groups. In subgroups B and S, resin nano ceramics showed the highest bond strength. In feldspar groups, subgroup B showed higher bond strength than the other subgroups. Conclusion This study demonstrates that lithium disilicate porcelain blocks required etching for repairing with composite material. Surface treatments did not increase the bond strength in feldspar ceramic groups and reduced the bond strength in resin nano ceramic groups.

Manufacturing of three-dimensional (3D) integrated circuit (IC) using through-silicon vias (TSVs) passes through a complex process and testing of TSVs is a critical issue to the researchers. Pre-bond testing eliminates bad dies before bonding. In this paper, we propose a heuristic approach for pre-bond TSV testing which reduces the test time considerably. The proposed method uses recursive bi-partitioning and padding of test sessions and runs in linear time.

Although static interlayer bond testing has been established for quality control during recent years its significance has been questioned and in the wake of this discussion several more realistic cyclic testing devices have been proposed. The Germany testing device developed at the University of Dresden even found entrance into the European test standards and the device has been commercially available for a couple of years. The paper presents an investigation dealing with the importance of interlayer bond testing for performance evaluation and focuses on a comparison of results from static and cyclic interlayer bond testing. Based on the comparison of static and cyclic bond testing the benefits from cyclic testing will be evaluated and a recommendation for the cyclic testing procedure will be presented.

Although static interlayer bond testing has been established for quality control during recent years its significance has been questioned and in the wake of this discussion several more realistic dynamic testing devices have been proposed with the purpose of determining the interlayer bond properties not only at failure but also during service life. The Germany testing device developed at the University of Dresden even found entrance into the European test standards and the device has been commercially available for a couple of years. The paper presents an investigation dealing with the importance of interlayer bond testing for performance evaluation and focuses on a comparison of results from static and dynamic interlayer bond testing. Based on the comparison of static and dynamic bond testing the benefits from dynamic testing will be evaluated and a recommendation for the dynamic testing procedure will be presented.

Made available in DSpace on 2018-12-11T17:12:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-07-01 National Natural Science Foundation of China Objective A recently-launched universal adhesive, G-Premio Bond, provides clinicians with the alternative to use the self-etch technique for bonding to dentine without waiting for the adhesive to interact with the bonding substrate (no-waiting self-etch; Japanese brochure), or after leaving the adhesive undisturbed for 10 s (10-s self-etch; international brochure). The present study was performed to examine in vitro performance of this new universal adhesive bonded to human coronal dentine using the two alternative self-etch modes. Methods One hundred and ten specimens were bonded using two self-etch application modes and examined with or without thermomechanical cycling (10,000 thermal cycles and 240,000 mechanical cycles) to simulate one year of intraoral functioning. The bonded specimens were sectioned for microtensile bond testing, ultrastructural and nanoleakage examination using transmission electron microscopy. Changes in the composition of mineralised dentine after adhesive application were examined using Fourier transform infrared spectroscopy. Results Both reduced application time and thermomechanical cycling resulted in significantly lower bond strengths, thinner hybrid layers, and significantly more extensive nanoleakage after thermomechanical cycling. Using the conventional 10-s application time improved bonding performance when compared with the no-waiting self-etch technique. Nevertheless, nanoleakage was generally extensive under all testing parameters employed for examining the adhesive. Conclusion Although sufficient bond strength to dentine may be achieved using the present universal adhesive in the no-waiting self-etch mode that does not require clinicians to wait prior to polymerisation of the adhesive, this self-etch concept requires further technological refinement before it can be recommended as a clinical technique. Clinical significance Although the surge for cutting application time to increase user friendliness remains the most frequently sought conduit for advancement of dentine bonding technology, the use of the present universal adhesive in the no-waiting self-etch mode may not represent the best use of the adhesive. Department of Prosthodontics Guanghua School and Hospital of Stomatology & Guangdong Provincial Key Laboratory of Stomatology Sun Yat-sen University Department of Restorative Dentistry Institute of Science and Technology São Paulo State University UNESP São Jose dos Campos Key Laboratory of Oral Medicine Guangzhou Institute of Oral Disease Stomatology Hospital of Guangzhou Medical University Department of Biomedical and Neuromotor Sciences DIBINEM University of Bologna – Alma Mater Studiorum College of Graduate Studies Augusta University State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases School of Stomatology The Fourth Military Medical University Department of Restorative Dentistry Institute of Science and Technology São Paulo State University UNESP São Jose dos Campos National Natural Science Foundation of China: 2015A030401035 National Natural Science Foundation of China: 81400555 National Natural Science Foundation of China: 81500883

Grouted dowel connections are used extensively in precast load bearing walls owing to their simple construction and forgiving tolerances. Current design guidelines do not adequately consider the composite nature of such connections. Moreover, robust numerical models for these connections are yet to be developed. Therefore, a finite element model of grouted dowel connections was developed in this paper. The model adopts a phenomenological bond&ndash, slip constitutive law to predict the load versus slip response of grouted bars and considers tensile yielding of the reinforcement. The local bond&ndash, slip law used was generated from carefully designed experiments to eliminate spurious effects associated with bond testing. The model was validated using experimental results on grouted connections, as well as data retrieved from the open literature. Excellent agreement between experimental and numerical results was observed, highlighting the accuracy of the model in depicting interfacial stresses of the assembly. The model requires simple calibration, is computationally efficient, and can accurately simulate the failure behavior of bars embedded in grouted connections.

In order to minimize the yield loss results from the stacking of good dies on a defective interposer, it is necessary to test the interposer before die stacking.

Reinforced concrete structures are subjected to weather conditions, chemical attack and other sources of deterioration that can affect their performance. In particular, corrosion of the internal steel reinforcement is considered to be one of the main causes of structural deterioration. A possible consequence of corrosion is cracking of the surrounding concrete. Visual inspections are often used to inform asset management strategies. Finding a relationship between cracks that are visible on the outer surface of a structure and corrosion of the internal reinforcement can be helpful when making assessment decisions. To this end, unconfined cylindrical concrete specimens with an embedded steel bar have been subjected to accelerated corrosion using an impressed current density of 200µA/cm2, leading to steel mass losses between 5-24%. This paper discusses the measured correlation between corrosion-induced surface crack widths and degree of reinforcement corrosion. The tests highlighted some limitations of a set-up that is commonly adopted for accelerated corrosion and concentric pull-out bond testing. The findings of this study represent a first step towards the standardisation of accelerated corrosion testing procedures using an impressed current.