• Title/Summary/Keyword: Mechanical properties

Search Result 16,973, Processing Time 0.044 seconds

Effect of the Coarse Aggregate Volume by High Temperature Mechanical Properties of Ultra High Strength Concrete (굵은골재의 용적이 초고강도 콘크리트의 고온역학적특성에 미치는 영향)

  • Hwang, Eui-Chul;Kim, Gyu-Yong;Choe, Gyeong-Cheol;Yoon, Min-Ho;Lee, Bo-Kyeong;Kim, Jung-Hyun
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2015.05a
    • /
    • pp.67-68
    • /
    • 2015
  • Recently, usage of ultra-high strengh concrete(UHSC) have been increased. Concrete has been recognized as a material which is resistant to high temperatures, but chemicophysical property of concrete is changed by the high temperature. So, mechanical properties of concrete may be reduced. Therefore, this study evaluated effect of the coarse Aggregate volume by high temperature mechanical properties of UHSC. Residual mechanical properties are evaluated under fine aggregate ratio 40,60% and 500℃ temperature on UHSC of W/B 15, 20%. As result, residual mechanical properties of UHSC are high by lower coarse aggregate volume.

  • PDF

Mechanical Properties and ASR Behavior of Recycled Glass Fine Aggregate Mortar Mixed with Mineral Admixture (혼화재를 혼입한 순환유리잔골재 모르타르의 역학적 특성과 ASR 거동)

  • Eu, Ha-Min;Kim, Guy-Yong;Park, Jun-Young;Sasui, Sasui;Choi, Byung-Cheol;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2023.05a
    • /
    • pp.195-196
    • /
    • 2023
  • In this study, the mechanical properties, alkali-silica reaction(ASR) expansion and residual mechanical properties after ASR of waste glass fine aggregate(GS) mortar according to mineral mixture were evaluated. As a result, it was found that the mineral mixture reduces the ASR expansion. However, mechanical properties and residual mechanical properties have decreased.

  • PDF

Effects of Combined Environmental Factors on Mechanical and Thermal Analysis Properties of Graphite/Epoxy Composites (복합적인 환경인자가 탄소섬유강화 복합재의 기계적 및 열분석 특성에 미치는 영향)

  • Lee, Sang-Jin;Lee, Jong-Keun;Yoon, Sung-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.26 no.7
    • /
    • pp.1416-1425
    • /
    • 2002
  • In this study, the effects of combined environmental factors on mechanical and thermal analysis properties of graphite/epoxy composites were evaluated by the use of an accelerated aging test. Environmental factors such as temperature, moisture. and ultraviolet were considered. A xenon-arc lamp was utilized for ultraviolet light. and exposure times of up to 3000 hours were applied. Several types of specimens - tensile. bending, and shear specimens those are transverse to the fiber direction, and bending specimens those are parallel to the tiber direction - were used to investigate the effects of environmental factors on mechanical properties of the composites. Also, glass transition temperature, storage shear modulus, loss shear modulus, and tan ${\delta}$ were measured as a function of exposure times through a dynamic mechanical analyzer. In addition. a suitable testing method for determining the effect of environmental factors on mechanical properties is suggested by comparing the results from using two different types of strain measuring sensors. Finally, composite surfaces exposed to environmental factors were examined using a scanning electron microscope.

Analysis of Microstructure and Mechanical Properties According to Heat Treatment Conditions in GMAW for Al 6061-T6 Alloy (Al 6061-T6 합금의 MIG 용접 후 열처리조건에 따른 미세조직 및 기계적 물성 분석)

  • Kim, Chan Kyu;Cho, Young Tae;Jung, Yoon Gyo;Kang, Shin Hyun
    • Journal of Welding and Joining
    • /
    • v.34 no.4
    • /
    • pp.34-39
    • /
    • 2016
  • Recently, aluminum alloy has used various industry, such as automobile, shipbuilding and aircraft because of characteristics of low density and high corrosion resistance. Al 6061-T6 is heat treatment materials so it has high strength and mostly used for assembly by mechanical fastening such as a bolting and riveting. In GMA (Gas Metal Arc) welding of alloy, some defects which are hot cracking, porosity, low-mechanical properties and large heat affected zone is generated, because of high heat conductivity. It reduces mechanical properties. In this study, the major factor effected on properties are analyzed after welding in Al 6061-T6 in GMAW, then optimize heat treatment conditions. Plate of Al 6061-T6 with a thickness of 12 mm is welded in V groove and applied welding method is butt joint. Mechanical properties and microstructure are analyzed according to heat treatment condition. Tensile strength, microstructure and Hardness are evaluated. Result of research appears that Al 6061-T6 applied heat treatment show outstanding mechanical properties.

Mechanical and wear properties evaluation of Al/Al2O3 composites fabricated by combined compo-casting and WARB process

  • Vini, Mohamad Heydari;Daneshmand, Saeed
    • Advances in Computational Design
    • /
    • v.7 no.2
    • /
    • pp.129-137
    • /
    • 2022
  • Compo-casting method is one of the popular technique to produce metal based matrix composites. But, one of the main challenges in this process is un-uniform spreading of reinforced subdivisions (particles) inside the metallic matrix and the lack of desirable mechanical properties of the final produced composites due to the low bonding strength among the metal matrix and reinforcement particles. To remove these difficulties and to promote the mechanical properties of these kind of composites, the WARM ARB technique was utilized as supplementary technique to heighten the mechanical and microstructural evolution of the casted Al/Al2O3 composite strips. The microstructure evolution and mechanical properties of these composites have been considered versus different WARM ARB cycles by tensile test, average Vickers micro hardness test, wear test and scanning electron microscopy (SEM). The SEM results revealed that during the higher warm- ARB cycles, big alumina clusters are broken and make a uniform distribution of alumina particles. It was shown that cumulating the forming cycles improved the mechanical properties of composites. In general, combined compo-casting and ARB process would consent making Al/Al2O3 composites with high consistency, good microstructural and mechanical properties.

Nonlinear deflection responses of layered composite structure using uncertain fuzzified elastic properties

  • Patle, B.K.;Hirwani, Chetan K.;Panda, Subrata Kumar;Katariya, Pankaj V.;Dewangan, Hukum Chand;Sharma, Nitin
    • Steel and Composite Structures
    • /
    • v.35 no.6
    • /
    • pp.753-763
    • /
    • 2020
  • In this article, the influence of fuzzified uncertain composite elastic properties on non-linear deformation behaviour of the composite structure is investigated under external mechanical loadings (uniform and sinusoidal distributed loading) including the different end boundaries. In this regard, the composite model has been derived considering the fuzzified elastic properties (through a triangular fuzzy function, α cut) and the large geometrical distortion (Green-Lagrange strain) in the framework of the higher-order mid-plane kinematics. The results are obtained using the fuzzified nonlinear finite element model via in-house developed computer code (MATLAB). Initially, the model accuracy has been established and explored later to show the dominating elastic parameter affect the deflection due to the inclusion of fuzzified properties by solving a set of new numerical examples.

Mechanical Properties of MWNT-Loaded Plain-Weave Glass/Epoxy Composites

  • Kim, Myung-Sub;Lee, Sang-Eui;Lee, Won-Jun;Kim, Chun-Gon
    • Advanced Composite Materials
    • /
    • v.18 no.3
    • /
    • pp.209-219
    • /
    • 2009
  • Carbon nanotubes (CNTs) have shown great potential for the reinforcement of polymers or fiber-reinforced composites. In this study, mechanical properties of multi-walled carbon nanotube (MWNT)-filled plain-weave glass/epoxy composites intended for use in radar absorbing structures were evaluated with regard to filler loading, microstructure, and fiber volume fraction. The plain-weave composites containing MWNTs exhibited improved matrix-dominant and interlaminar fracture-related properties, that is, compressive and interlaminar shear strength. This is attributed to strengthening of the matrix rich region and the interface between glass yarns by the MWNTs. However, tensile properties were only slightly affected by the addition of MWNTs, as they are fiber-dominant properties.

Mechanical properties of top neck mollusks shell nano composite in different environmental conditions

  • Masir, Amin Nouroozi;Darvizeh, Abolfazl;Zajkani, Asghar
    • Advances in materials Research
    • /
    • v.7 no.3
    • /
    • pp.185-194
    • /
    • 2018
  • The mechanism of biological materials structure is very complex and has optimal properties compared to engineering materials. Top Neck mollusks shells, as an example of biological materials, have hierarchical structure, which 95 percent of its structure is Aragonite and 5 percent organic materials. This article detected mechanical properties of the Top Neck mollusks shell as a Nano composite using Nano-indentation method in different situations. Research findings indicate that mechanical properties of the Top Neck mollusks shell including elastic modulus and hardness are higher than a fresh one preserved in -50 centigrade and also a Top Neck mollusks shell preserved in environmental conditions. Nano-indentation test results are so close in range, overall, that hardness degree is 3900 to 5200 MPa and elastic modulus is 70 to 85 GPa.

Changes of Physical and Mechanical Properties of Firefighter Protective Clothing After Radiant Heat Exposure (노출시간과 열강도에 따른 복사열 노출후의 소방보호복의 물리적 특성과 역학적 특성변화)

  • ;N.Pan;G.Sun
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.23 no.6
    • /
    • pp.853-863
    • /
    • 1999
  • the change of physical properties (thickness, weight, air permeability) and mechanical properties(abrasion resistance breaking load and displacement) of samples were determined after heat exposure by a RPP tester. The effect of exposure time and heat flux intensity on the changes and the relationship between physical properties and mechanical properties were investigated. FR treated cotton Kevlar/PBI and Nomex with different structureal characteristics were chosen for specimens. The changes of physical properties and mechanical properties were calculated based on their initial values before heat exposure. The longer exposure time and the high heat flux intensity the more changes of those properties. Heat flux intensity was more effective on the changes, The showed to be affected by an interplay of shrinkage and pyrolysis products loss. The changes of thickness and abrasion resistance showed to be higher for plain weave fabric and those of air permeabiliyt and breaking load and displacement for twill weave fabric. While FR treated cotton which have high RPP value experienced serious and detrimental changes after heat exposure Kevlar/PBI which has low RPP value showed no high changes. In conclusion it could be confirmed that when total performance of a protective clothing is estimated retention capability of physical and mechanical properties after heat exposure as well as RPP value must be considered.

  • PDF

Effect of Eco-friendly Inorganic Flame Retardants on Mechanical and Flame-Retardant Properties of EPDM Compound

  • Do, Jong Hwan;Kim, Do Young;Seo, Kwan Ho
    • Elastomers and Composites
    • /
    • v.55 no.1
    • /
    • pp.40-45
    • /
    • 2020
  • In this study, the mechanical and flame-retardant properties of ethylene-propylene-diene-termonomer (EPDM) based rubber compounds and various other environmentally friendly inorganic flame retardants were investigated. Alumina trihydrate (ATH) and magnesium hydroxide (MDH) were used as inorganic flame retardants. The mechanical properties after thermal oxidation aging and the flame-retardant properties of the EPDM compounds were measured using a moving die rheometer, a universal testing machine, a compression set, and a UL 94 V flammability test. We focused on how the properties were affected by the type and amount of flame retardants. The results demonstrated that the optimal mechanical and flame-retardant V-0 grade properties were obtained at an ATH content of 200 phr.