• Journal of the Korean Society of Clothing and Textiles
• /
• v.23 no.1
• /
• pp.66-77
• /
• 1999

For this study It was measured the seam puckering based on the mechanical properties of tencel under the proper condition of needlework and machine sewing analyzed the mechanical properties which re influenced to the seam puckering and estimated the seam puckering based on the mechanical properties. The results of this study are as follows : There are three types of the seam puckering for each step which is caused by repeated washing and press. Concerning the seam puckering with the number of washing the more the number of washing is increased the less the seam puckering is decreased. Concerning the mecanical properties of the sample with the seam puckering. The seam puckering is related to LT positively B, 2HB, T, W negatively Among the mechanical properties LT, B, 2HB, T, W are most influenced to the seam puckering. Judging from the result of estimating seam puckering based on mechanical properties the estimate-formula is satisfied in this study.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.6 no.3
• /
• pp.723-736
• /
• 2014

Glass Fiber Reinforced Plastic (GFRP) structures are primarily manufactured using hand lay-up or vacuum infusion techniques, which are cost-effective for the construction of marine vessels. This paper aims to investigate the mechanical properties and failure mechanisms of the hybrid GFRP composites, formed by applying the hand lay-up processed exterior and the vacuum infusion processed interior layups, providing benefits for structural performance and ease of manufacturing. The hybrid GFRP composites contain one, two, and three vacuum infusion processed layer sets with consistent sets of hand lay-up processed layers. Mechanical properties assessed in this study include tensile, compressive and in-plane shear properties. Hybrid composites with three sets of vacuum infusion layers showed the highest tensile mechanical properties while those with two sets had the highest mechanical properties in compression. The batch homogeneity, for the GFRP fabrication processes, is evaluated using the experimentally obtained mechanical properties.

• Advances in concrete construction
• /
• v.14 no.1
• /
• pp.15-34
• /
• 2022

The use of waste rubber in concrete can reduce natural aggregate consumption and improve some technical properties of concrete. Although there are several equations for estimating the mechanical properties of concrete containing waste rubber, limited numbers of machine learning-based models have been proposed to predict the mechanical properties of rubbercrete. In this study, an extensive database of the mechanical properties of rubbercrete was gathered from a comprehensive survey of the literature. To model the mechanical properties of rubbercrete, M5P tree and linear gene expression programming (LGEP) methods as two machine learning techniques were employed to achieve reliable mathematical equations. Two procedures of input variable selection were considered in this study. The crucial component ratios of rubbercrete and concrete age were assumed as the input variables in the first procedure. In contrast, the volumes of the coarse and fine waste rubber and the compressive strength of concrete without waste rubber were considered the second procedure of the input variables. The results show that the models obtained by LGEP are more accurate than those achieved by the M5P model tree and existing traditional equations. Besides, the volumes of the coarse and fine waste rubber and the compressive strength of concrete without waste rubber are better predictors of the mechanical properties of rubbercrete compared to the first procedure of input variable selection.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.36 no.1
• /
• pp.9-15
• /
• 2004

Micro inorganic solids and dissolved materials contained in the white water of linerboard process was obtained by centrifugation, and their characteristics were analyzed along with their effects on the mechanical properties of linerboard. Micro inorganic materials had little influence on tensile index and ZDT of UKP sheets. They showed rather a positive effect on mechanical properties of KOCC sheets due to adsorbed polymer. Mechanical properties of KOCC sheets decreased remarkably when the concentration of dissolved materials increased especially above 4000 ppm.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2004.10a
• /
• pp.31-34
• /
• 2004

Carbon nanofiber exhibits superior and often unique characteristics of mechanical, electrical chemical and thermal properties. In this study, For improvement of the mechanical properties of composites, carbon nanofiber reinforced hybrid composites was investigated. For the effect of dispersion, The dispersion methods of solution blending and mechanical mixing were used. The mixing of solution blending method was used using ultrasonic. Dispersion of carbon nanofiber was observed by scanning electron microscope (SEM). Mechanical properties were measured by universal testing Machine (UTM).

• Journal of the Korean Society for Heat Treatment
• /
• v.3 no.1
• /
• pp.25-33
• /
• 1990

Recently developed austempered ductile irons(A.D.I.) have good mechanical properties. However it is still needed to examine the relationships between microstructures related to banitic reaction and the mechanical properties. From the mechanical tests such as impact test, hardness test, tensile test, and the microstructure observations, we concluded that the good mechanical properties of A.D.I. came from the fine banitic ferrite structure formed during the first stage of the austempering reaction.

• Journal of Powder Materials
• /
• v.18 no.1
• /
• pp.64-72
• /
• 2011

Nondestructive instrumented indentation test is the method to evaluate the mechanical properties by analyzing load - displacement curve when forming indentation on the surface of the specimen within hundreds of micro-indentation depth. Resistance spot welded samples are known to difficult to measure the local mechanical properties due to the combination of microstructural changes with heat input. Particularly, more difficulties arise to evaluate local mechanical properties of resistance spot welds because of having narrow HAZ, as well as dramatic changed in microstructure and hardness properties across the welds. In this study, evaluation of the local mechanical properties of resistance spot welds was carried out using the characterization of Instrumented Indentation testing. Resistance spot welding were performed for 590MPa DP (Dual Phase) steels and 780MPa TRIP (Transformation Induced Plasticity) steels following ISO 18278-2 condition. Mechanical properties of base metal using tensile test and Instrumented Indentation test showed similar results. Also it is possible to measure local mechanical properties of the center of fusion zone, edge of fusion zone, HAZ and base metal regions by using instrumented indentation test. Therefore, measurement of local mechanical properties using instrumented indentation test is efficient, reliable and relatively simple technique to evaluate the tensile strength, yield strength and hardening exponent.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.5
• /
• pp.1237-1240
• /
• 2010

The mechanical properties of multiwalled carbon nanotubes (MWNTs)-reinforced epoxy matrix composites with different weight percentages of MWNTs have been investigated. Also, the morphologies and failure behaviors of the composites after mechanical tests are studied by SEM and TEM analyses. As a result, the addition of MWNTs into the epoxy matrix has a remarkable effect on the mechanical properties. And the fracture surfaces of MWNTs/epoxy composites after flexural strength tests show different failure mechanisms for the composites under different nanotube contents. Also, a chemical functionalization of MWNTs can be a useful tool to improve the dispersion of the nanotubes in an epoxy system, resulting in increasing the mechanical properties of the composite materials studied.

• Textile Coloration and Finishing
• /
• v.20 no.6
• /
• pp.63-68
• /
• 2008

The hand of the sensitive mixture fabrics was analysed and discussed with measured mechanical properties of two kinds of woven fabrics according to the characteristics of air-jet loom. The 16 mechanical properties such as tensile, bending, shear, compression and surface were measured using KES-FB system and their differences of the mechanical properties between domestic and foreign looms were analysed with the deviation according to the position of the specimen. And also these mechanical properties according to the domestic and Japan air-jet looms were analysed and discussed with warp and weft insertion tensions during weaving. This research is aiming to make a data base of fabric mechanical properties and, these analysed data are given to weaver as a basic research data related to the effects of loom characteristics to the sensitive mixture fabrics required from weaving fields.

• Laser Solutions
• /
• v.9 no.1
• /
• pp.25-29
• /
• 2006

This study aimed to investigate the change of mechanical properties with the rolling direction and shielding condition during laser welding of AZ31 magnesium alloy. AZ31 magnesium alloy sheets of 1mm thickness were welded using a continuous wave Nd:YAG laser with and without Ar shielding gas. The effect of Ar shielding gas and rolling direction on the mechanical properties were investigated using Vickers hardness, transverse-weld tensile. Porosity in the weld metals was investigated using an optical microscope. The experimental results showed that mechanical properties of AZ31 magnesium alloy laser welds were upgraded compared to those of base metal. Mechanical properties of AZ31 magnesium alloy laser welds were not substantially changed when Ar shielding gas was supplied.