• Carbon letters
• /
• 제1권3_4호
• /
• pp.138-142
• /
• 2001

The effect of electrochemical surface treatments in KOH chemical solution on microstructures of carbon blacks was investigated in terms of surface functional values and XRD measurements. And their mechanical interfacial properties of the carbon blacks/rubber composites were studied by the composite tearing energy ($G_{IIIC}$). It was found that the development of basic-surface functional groups lead to the significant physical changes of carbon blacks, such as, decrease of the interlayer spacing ($d_{002}$), increase of the crystalline size along c-axis ($L_c$), and increase of degree of crystalline (${\chi}_c$). This treatment is possibly suitable for carbon blacks to be incorporated in a hydrocarbon rubber matrix, resulting in improving the hardness and tearing energy of the resulting composites.

• 한국의류학회지
• /
• 제22권8호
• /
• pp.1060-1068
• /
• 1998

The effects of various catalysts and softners on the anti-crease finish of ramie with glyoxal were investigated. A number of metal salts commonly used as Lewis acid catalysts in DP finishing of cotton with formaldehyde and N-methylol agents were screened for glyoxal treatment of ramie fabric. Various organic and inorganic acids were mixed with Lewis acid catalyst as co-catalysts to improve catalytic activity. As a result, the combination of aluminum sulfate and citric acid was proven highly effective in catalyzing the crosslinking of ramie cellulose by glyoxal under lower curing temperature. With a mixed catalyst, performance properties, such as whiteness and tearing strength as well as wrinkle recovery of treated ramie fabric were improved as compared with that treated with aluminum sulfate alone. Additional improvement of tearing strength and wrinkle recovery was achieved by applying silicons softner in the treatment bath.

• 한국의류산업학회지
• /
• 제11권3호
• /
• pp.465-468
• /
• 2009

In this study, acid cellulase was used to treat denim fabrics by varying pH, temperature, enzyme concentration, treatment time and non-ionic surfactant (Triton X-100) concentration. Treatment condition was controlled based on the weight loss. The characteristics of enzyme-treated fabrics were measured in terms of tearing strength, stiffness, and color difference. The optimum conditions for cellulase treatment of denim fabric were pH 5.0, $50^{\circ}C$, 3% (o.w.f.), 90minutes. The weight loss did not change significantly with the addition of a non-ionic surfactant, but it improved when more non-ionic surfactant were used. The tearing strength of enzyme-treated denim fabrics did not deteriorate. The stiffness of the treated fabrics improved with the enzymatic treatment with and without the non-ionic surfactant. The difference in color of fabrics treated with enzyme increased.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 추계학술대회논문집A
• /
• pp.395-401
• /
• 2000

Rubber is used extensively in many industries because of its large reversible elastic deformation, excellent damping and energy absorption characteristics, and wide availability. Therefore it becomes very important to evaluate fracture characteristics of rubber. Tearing energy and J-integral have been used as fracture parameters of rubber. The J-integral values for pure shear and single edge specimen are calculated by finite element analysis and compare with theoretical values. Finite element analysis is performed by ABAQUS.

• Journal of Mechanical Science and Technology
• /
• 제15권1호
• /
• pp.35-43
• /
• 2001

Both tensile and tear properties of short-fiber reinforced Chloroprene rubber have been studied as functions of the fiber aspect ratio and fiber content. Both properties increased when both the fiber aspect ratio and fiber content were increased. The fiber reinforced rubbers exhibited maximum values of these properties at a fiber aspect ratio of about 300. When the fiber aspect ratio exceeds 400, the mechanical properties decreased with the fiber content because of the non-uniform dispersion of fibers. The tensile modulus was compared with the prediction by the Halpin-Tsai equations for randomly oriented cases. A bonding agent was used in the fiber treating process. It was found that the ultimate tensile strength, torque, tearing energy and tensile modulus of the rubbers with treated fibers were much higher than those with untreated ones.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제24권2호
• /
• pp.199-214
• /
• 2020

This paper describes the development of a parallel computational algorithm based on the finite element tearing and interconnecting (FETI) method that uses a local Lagrange multiplier. In this approach, structural computational domain is decomposed into non-overlapping sub-domains using local Lagrange multiplier. The local Lagrange multipliers are imposed at interconnecting nodes. 8-node solid element using extra shape function is adopted by using the representative volume element (RVE). The parallel computational algorithm is further established based on message passing interface (MPI). Finally, the present FETI-local approach is implemented on parallel hardware and shows improved performance.

• Nuclear Engineering and Technology
• /
• 제48권5호
• /
• pp.1252-1263
• /
• 2016

This paper presents a numerical method to simulate ductile tearing in cracked components under high strain rates using finite element damage analysis. The strain rate dependence on tensile properties and multiaxial fracture strain is characterized by the model developed by Johnson and Cook. The damage model is then defined based on the ductility exhaustion concept using the strain rate dependent multiaxial fracture strain concept. The proposed model is applied to simulate previously published three cracked pipe bending test results under two different test speed conditions. Simulated results show overall good agreement with experimental results.

• 폴리머
• /
• 제38권5호
• /
• pp.664-670
• /
• 2014

The effects of different filling materials and stabilizers in polymer based materials that are used as shoe soles in the shoemaking industry on the mechanical properties (strength, failure, tensile, tearing, bending etc.) of the final products have been examined in this study. Natural rubber (NR RSS3) and styrene-butadiene rubber (SBR 1502) were used as the main matrix material. New compounds were formed by replacing the fillings in the general compound of the existing factory ($SiO_2$, $CaCO_3$) with 40% (1200 g) blast furnace flue dust, rice husk, reclaimed rubber (recycled) and wood ash. Comparison of the new compounds with the existing compounds revealed a decrease in hardness, density, dimension stability, bending, tearing, % elongation and failure strength and an increase in wearing.

• 한국해양공학회지
• /
• 제14권1호
• /
• pp.44-51
• /
• 2000

Safety and integrity are required for reactor pressure vessels because they are operated in high temperature. There are single specimen method multiple specimen method and load ratio analysis method which used as evaluation of safety and integrity for reactor pressure vessels. In this study the fracture resistance curve(J-R curve) elastic-plastic fracture toughness($J_{IC}$) and material tearing modulus ($T_{mat}$) of SA 508 class 3 alloy steel used as reactor pressure vessel steel are measured and evaluated at room temperature 20$0^{\circ}C$ and 30$0^{\circ}C$ according to unloading compliance method and load ration analysis method. And then the comparison with experimental $J_{IC}$ and theoretical$J_{IC}$ by local fracture strain is managed.

• Elastomers and Composites
• /
• 제1권1호
• /
• pp.41-48
• /
• 1966

The physical properties of rubber coated fabrics, treated by means of spreading and topping process were studied. 1. The tearing strength of the rubber coated fabrics has shown decreasing tendency in comparison with fabric itself 2. Generally, the tearing strength is inversely proportional to the adhesion. 3. The value of hydrostatic pressure is in proportion to the density and tensile strength of the fabrics. 4. The topping process shows greater difference in adhesion initial and after water immersion than spreading process.