J. Useche, P. Sollero, E.L. Albuquerque¹, L. Palermo²

Structural Durability & Health Monitoring, Vol.4, No.2, pp. 107-116, 2008, DOI:10.3970/sdhm.2008.004.107

Abstract The fracture analysis of cracked thick plates repaired with adhesively bonded composite patches using a boundary element formulation is presented. The shear deformable cracked isotropic plate was modeled using the dual boundary method. In order to model the repair, a three parameter boundary element formulation was established. This formulation is based on Kirchhoff's theory for symmetric layer composite plates and considers the transversal deflection and two in-plane rotations. Interaction forces and moments between the cracked plate and the composite repair were modeled as distributed loading, and discretized using continuous and semi-discontinuous domain cells. Coupling equations, based on kinematic compatibility and… More >

J. Mohan¹, D. Carolan¹, N. Murphy¹, A. Ivankovic¹, D. Dowling¹

Structural Durability & Health Monitoring, Vol.3, No.2, pp. 81-86, 2007, DOI:10.3970/sdhm.2007.003.081

Abstract The aim of this work is to investigate the influence of a variety of plasma treatments on the surface properties of an epoxy-based composite material and to establish a relationship between these properties and the subsequent mechanical behaviour of adhesively bonded joints. To this end, specimens were subjected to three different types of plasma treatment: two short treatments (2min) of He and He plus O₂, and one long treatment (15min) of He plus O₂. The variation in surface energy of the composite specimens was examined in each case over a period of up to 3 days using contact angle measurements.… More >

J. Useche¹, P. Sollero², E.L. Albuquerque², L. Palermo³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 175-182, 2008, DOI:10.3970/icces.2008.006.175

Abstract The computational fracture analysis of cracked thick plates repaired with adhesively bonded composite patches using a boundary element formulation is presented. The shear deformable cracked isotropic plate was modeled using the Reissner's plate theory. In order to model the repair, a three parameter boundary element formulation, based on Kirchhoff's theory for symmetric layered composite plates was established. Interaction forces and moments between the cracked plate and the composite repair were modeled as distributed loads. Coupling equations, based on kinematic compatibility and equilibrium considerations for the adhesive layer, were established. In-plane shear-deformable model with transversal stiffness was considered in order to… More >

Waruna Seneviratne¹, John Tomblin², Suranga Gunawardana³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 81-86, 2007, DOI:10.3970/icces.2007.004.081

Abstract An experimental study was conducted to investigate the use of fracture mechanics to predict failure initiation of adhesive joints. Most practical plane fracture problems are mixed mode and failure initiation of adhesive joints is a result of such conditions. It is widely accepted that a useful method for characterizing the toughness of bonded joints is to measure the fracture toughness; energy per unit area needed to produce failure. For a given adhesive, mode mixity has a dependency towards fracture toughness and fracture toughness is directly associated with stress. Main goal in this investigation was to demonstrate the capability of utilizing… More >

L. Roy Xu¹, Charles M. Lukehart², Lang Li², Huacheng Kuai¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.3, No.1, pp. 9-14, 2007, DOI:10.3970/icces.2007.003.009

Abstract Graphitic carbon nanofibers were used to reinforce epoxy resin to form nanocomposite adhesive bonding. Good dispersion and polymer wetting of the GCNF component is evident on the nanoscale. Tensile and shear joint strength measurements were conducted for metal-metal and polymer-polymer joints using pure epoxy and nanocomposite bonding. Very little bonding strength increase, or some bonding strength decrease, was measured. More >

Swarnalata Sahoo^1,2*, Hemjyoti Kalita¹, Smita Mohanty^1,2, Sanjay Kumar Nayak^1,2

Journal of Renewable Materials, Vol.6, No.1, pp. 117-125, 2018, DOI:10.7569/JRM.2017.634155

Abstract In the current work, we have synthesized vegetable oil-based polyurethane-OMMT clay nanocomposite (PUNC) adhesive with the incorporation of different wt% of organically modified nanoclay (1 to 5 wt%) into the biobased polyurethane (PU) matrix through in-situ polymerization process via ultrasonication method. At the initial stage, PU adhesive was prepared using polyol and partially biobased aliphatic isocyanate, wherein polyol was derived from the transesterified castor oil using ethylene glycol. The formation of PU and PUNC adhesive was confirmed using Fourier transform infrared (FTIR) spectroscopy analysis. The tensile strength of PU with different wt% of nanoclay was determined and the analysis showed… More >

Arun Kumar Pradhan^1,2*, Prafulla Kumar Sahoo¹, Pradeep Kumar Rana²

Journal of Renewable Materials, Vol.5, No.5, pp. 371-379, 2017, DOI:10.7569/JRM.2017.634129

Abstract Chitosan grafted with poly(methyl-methacrylate) (PMMA) and adsorbed with kaolin functionalized as bioadhesive was prepared via emulsion polymerization technique and physiochemically characterized as a bone-graft substitute. The so prepared grafted bioactive bone cement (BBC) bionanocomposites (BNCs), chitosan-g-PMMA/kaolin, was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, field-emission scanning electron microscopy (FESEM) and thermogravimetric analysis (TGA). The water uptake, retention ability and the nanosize particle arrangement in the polymeric BBC-BNCs were studied along with the mechanical and biodegradation properties. These preliminary investigations of the BNCs will open the door for their use in bioadhesive bone-cement implants in the future. More >

Flávio Pereira¹, João Pereira², Nádia Paiva³, João Ferra³, Jorge Manuel Martins^1,4, Fernão D. Magalhães¹, and Luísa Carvalho^1,4*

Journal of Renewable Materials, Vol.4, No.1, pp. 41-46, 2016, DOI:10.7569/JRM.2015.634128

Abstract This work studies the use of soy protein as a natural formaldehyde scavenger in wood particleboard production. The protein is incorporated in two forms: a) as a powder, during the blending process of wood particles with urea-formaldehyde binder resin, and b) as an aqueous solution, added at different times during resin synthesis. Analysis of variance (ANOVA) was used to evaluate the signifi cance level of two effects (amount of added soy and time of addition) on internal bond strength, thickness swelling, and formaldehyde content of the resulting panels. The results showed that soy protein can contribute to decrease the formaldehyde… More >

Shaohua Chen^*

Molecular & Cellular Biomechanics, Vol.5, No.2, pp. 97-106, 2008, DOI:10.3970/mcb.2008.005.097

Abstract Recently, contact mechanics has been widely used to get some understanding of the biological adhesion mechanisms, such as cell-cell adhesion, insects' adhesion and locomotion. JKR theory is usually adopted as a basis, in which the interaction of molecules is considered in contrast to the classical Hertz solution. In this paper, two problems are summarized, which may give some insights to cells or bio-molecules sensitivity to environmental signals: (1) cell reorientation on a stretched substrate; (2) spontaneous detachment between cells or bio-molecules under the variation of environmental signals. The intention here is only to illustrate the possibilities that contact mechanics may… More >

Hai Ngu^*, Lan Lu^*, Sara J. Oswald^*, Sarah Davis^*, Sumona Nag^*, Frank C-P Yin^†

Molecular & Cellular Biomechanics, Vol.5, No.1, pp. 69-82, 2008, DOI:10.3970/mcb.2008.005.069

Abstract Endothelial cells subjected to cyclic stretching change orientation so as to be aligned perpendicular to the direction of applied strain in a magnitude and time-dependent manner. Although this type of response is not the same as motility, it could be governed by motility-related factors such as substratum adhesiveness and actin-myosin contractile level. To examine this possibility, human aortic endothelial cells (HAEC) were uniaxially, cyclically stretched on silicone rubber membranes coated with various concentrations of fibronectin, collagen type IV and laminin to produce differing amounts of adhesiveness (measured using a radial flow detachment assay). Cells were subjected to 10% pure cyclic… More >