Kun Li, Xiaona Li, Jing Luo, Jingjing Li, Qiang Gao^*, Jianzhang Li^*

Journal of Renewable Materials, Vol.5, Suppl.1, pp. 31-38, 2017, DOI:10.7569/JRM.2017.634131

Abstract The objective of this study was to use soybean meal and 1,4-butanediol diglycidyl ether (BDDE) to develop a highly water-resistant, soy-based bioadhesive for plywood fabrication. The physical properties and performance characteristics of the resulting adhesive, including solid content, viscosity, water resistance, crystallinity, fracture morphology, thermal behavior, and cracks, were evaluated. The proposed adhesive was compared against the traditional soy adhesive with polyamidoamine-epichlorohydrin (PAE). Results showed that adding 8 g of BDDE into the adhesive formulation improved the solid content up to 32.83% and reduced the viscosity to 27340 mPa·s. The wet shear strength of plywood More >

Bernal Sibaja^1,2,3, Camila Pereira Matheus^1,2, Ricardo Ballestero Mendez^1,2,Ramsis Farag^1,2,4, J. R. Vega-Baudrit³, Maria L. Auad^*,1,2

Journal of Renewable Materials, Vol.5, No.3-4, pp. 241-250, 2017, DOI:10.7569/JRM.2017.634114

Abstract The thermo-mechanical properties and linear fracture mechanics of acrylated soybean oil and the triglycidylated ether of α-resorcylic acid interpenetrated networks as a function of their weight composition are the focus of Part 2 of this article. Thermo-mechanical characterization showed that the obtained materials behave as thermoset amorphous polymers, and that both the modulus and glass transition are extremely dependent on the epoxy/acrylate weight ratio. Modulus values ranged from 0.7 to 3.3 GPa at 30 °C, and glass transition temperatures ranged from around 58 °C to approx. 130 °C. No synergistic effect on these two properties More >

Longjia Li^1,2, Tianbao Qian^2,3, Fei Hang^{1, 2, *}

Molecular & Cellular Biomechanics, Vol.14, No.4, pp. 221-234, 2017, DOI:10.3970/mcb.2017.014.221

Abstract Bone is an important natural hierarchical biomaterial which supports human body and protect organs. Its mechanical property has been researched extensively. In this experimental work, 3D microscope and scanning electron microscope (SEM) were used to research crack expansion on bovine femur cortical bone transverse section. Softwares such as image J and Photoshop were used in image and data analyses. Our results suggested that the interface energy of extending through osteons is smaller than the interface energy of extending along cement lines. Cracks are more likely to extend through osteons. Further investigations are needed to reduce More >

M.N.D. Cherief¹, M. Elmeguenni¹, M. Benguediab¹

CMC-Computers, Materials & Continua, Vol.51, No.3, pp. 187-201, 2016, DOI:10.3970/cmc.2016.051.187

Abstract Impact behavior of polymers has received considerable attention in recent years, and much work based on fracture mechanic approaches has been carried out. In this paper, fracture behavior in large deformation of a high density polyethylene (HDPE) materials was investigated through experimental impact testing on single edge notched specimen (SENB) and by using theoretical and analytical fracture criteria concepts. Moreover, a review of the main fracture criteria is given in order to characterize the toughness of this polymer in the both cases (static and dynamic). The fractured specimens obtained from the Charpy impact test were More >

L. Távara¹, V. Manticˇ ¹, E. Graciani¹, J. Cañas¹, F. París¹

CMES-Computer Modeling in Engineering & Sciences, Vol.58, No.3, pp. 247-270, 2010, DOI:10.3970/cmes.2010.058.247

Abstract The problem of a crack in a thin adhesive layer is considered. The adherents may have orthotropic elastic behavior which allows composite laminates to be modeled. In the present work a linear elastic-brittle constitutive law of the thin adhesive layer, called weak interface model, is adopted, allowing an easy modeling of crack propagation along it. In this law, the normal and tangential stresses across the undamaged interface are proportional to the relative normal and tangential displacements, respectively. Interface crack propagation is modeled by successive breaking of the springs used to discretize the weak interface. An… More >

Q. Ma^1,2, J. L. Beuth¹, G. H. Meier³, F. S. Pettit³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.1, pp. 13-18, 2008, DOI:10.3970/icces.2008.008.013

Abstract This paper addresses the mechanics of indentation-induced delamination of a coating on a multi-layered hollow cylinder, for application to toughness testing of thermal barrier coating (TBC) systems. An electron-beam physical vapor deposition (EB-PVD) TBC system has been analyzed through a contact finite element model using a standard conical indenter impressed vertically on the top of the cylinder. Two cylinder sizes used in thermal-mechanical fatigue tests in literature have been considered in the analysis, with outer radii of 5.11 mm and 3.08 mm, and inner radii of 3.00 mm and 0.97 mm, respectively. Two boundary conditions More >

Y. Shimamura¹, Y. Shibata², K. Tohgo³, H. Araki⁴

The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 189-194, 2008, DOI:10.3970/icces.2008.006.189

Abstract Polylactic acid (PLA) is a biodegradable plastic made from lactic acid, and can be produced by renewable raw materials. The mechanical properties of PLA are, however, not sufficient for structural materials. In our study, carbon nanofiber reinforced PLA was fabricated to overcome the deficiency of PLA and the mechanical properties were measured at room and elevated temperatures. Vapor grown carbon fiber (VGCF) was used for reinforcement. Three point bending specimens were fabricated by using injection molding, and then bending stiffness, bending strength and fracture toughness were measured for amorphous and crystallized specimens. As a result, More >

Asif Husain¹, M. Guniganti², D. K. Sehgal², R. K. Pandey²

CMC-Computers, Materials & Continua, Vol.8, No.3, pp. 133-150, 2008, DOI:10.3970/cmc.2008.008.133

Abstract This paper describes an approach to identify the mechanical properties i.e. fracture and yield strength of steels. The study involves the FE simulation of shear punch test for various miniature specimens thickness ranging from 0.20mm to 0.80mm for four different steels using ABAQUS code. The experimental method of the miniature shear punch test is used to determine the material response under quasi-static loading. The load vs. displacement curves obtained from the FE simulation miniature disk specimens are compared with the experimental data obtained and found in good agreement. The resulting data from the load vs.… More >

Guocai Chai

Structural Durability & Health Monitoring, Vol.3, No.3, pp. 191-196, 2007, DOI:10.3970/sdhm.2007.003.191

Abstract Duplex stainless steels (DSS) are a group of steels consisting of approximately equal volume fraction of austenite and ferrite. In this study, the influences of the factors such as hydrogen, ferrite phase, cold deformation, grain size, and cluster due to the spinodal decomposition and precipitates or secondary phases in a super duplex stainless steel on the ductile to brittle transition (DBT) are investigated. Three types of DBT curves: toughness versus temperature, hardness and amount of precipitates, have been built to describe the DBT behavior in DSS. These curves are important to provide the information about 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… More >