• Title/Summary/Keyword: no-tension materials

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Some explicit solutions to plane equilibrium problem for no-tension bodies

  • Lucchesi, Massimiliano;Zani, Nicola
    • Structural Engineering and Mechanics
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    • v.16 no.3
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    • pp.295-316
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    • 2003
  • A method is presented to integrate explicitly certain equilibrium problems for no-tension bodies, in absence of body forces and under the assumption that two of the principal stresses are everywhere null. The method is exemplified in the case of rectangular panels, clamped at their bottoms and loaded at their tops.

Experimental Procedure for Design Allowances of Mechanical Joint in Non-flammable Composites (불연성 복합재의 기계적 접합부 설계 허용치 도출을 위한 실험적 절차)

  • Lee Chang-Hun;Kim Jin-Bong;Park Ji-Sang;Hwang Byung-Sun
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2004.04a
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    • pp.258-261
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    • 2004
  • This paper contains the tension-tension, the tension-tension bearing and the tension-tension steel bolt joint fatigue characteristics of glass fabric/phenol composite laminates. The experimental results show that the bearing and the steel bolt joint fatigue characteristics of the material is so excellent compared with the simple tension fatigue characteristics, that there are no needs of additional strengthening for mechanical joint parts when the parts are properly designed.

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Failure and Deformation Analyses of 3-ply Mg/Al/STS Clad-Metalin Bending (굽힘시험시의 Mg/Al/STS 3층 클래드재의 변형 및 파단특성 분석)

  • Kim, In-Kyu;Song, Jun-Young;Hwan, Oh-Ki;Hong, Sun Ig
    • Korean Journal of Metals and Materials
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    • v.50 no.5
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    • pp.345-351
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    • 2012
  • A three-point bending test was performed on roll-bonded Mg/Al/STS clad-metal plates under two different testing conditions (Mg layer in tension, or STS in tension) and their mechanical response and fracture behavior were investigated. Bending strength was found to be greater under the condition of Mg layer in tension. Heat treatment at $200^{\circ}C$ increased the bending formability, suggesting the interfacial strength increased at $200^{\circ}C$. Under the condition of Mg in tension, the clad heat-treated at $300^{\circ}C$ and $400^{\circ}C$ fractured in two steps, with the first step associated with the interfacial fracture between Mg and Al, and the second the fracture of the Mg layer. STS/Al layers were found to be bent without complete fracture. Under the condition of STS in tension, the clad heat-treated at $300^{\circ}C$ and $400^{\circ}C$ exhibited a very small load drop at the displacement, which is similar to that of the first load drop associated with the interfacial fracture under the condition of Mg in tension. In this case, no interfacial cracks were found and the complete cut-through fracture of clad was observed at low temperature heat treatment conditions, suggesting excellent interfacial strength. When the heat treatment temperature was higher than $300^{\circ}C$, interfacial cracks were observed. The local stress condition and the position of the interface with respect to the surface were found to have a great influence on the fracture behaviors of clad metals.

A Study on the Vibration Behavior of Composite Laminate under Tensile Loading by ESPI (ESPI에 의한 인장하중 하에서의 복합재 적층판의 진동 거동에 관한 연구)

  • Yang, Seung-Pil;Kim, Koung-Suk;Jung, Hyun-Chul;Chang, Ho-Seob;Kim, Chong-Soo
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.516-521
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    • 2000
  • Most of studies, using ESPI method, have handled tension, thermal and vibration analysis, and is limited to isotropic materials. However, tension and vibration simultaneously are loaded in real structure. Also, almost study using ESPI method is locally limited to the analysis on the isotropic materials and a few studies on the anisotropic materials have reported. Existing methods, such as the accelerometer method and FEA method, to analyze vibration have some disadvantages. Using the accelerometer method that is generally used to analyze vibration phenomena, it is impossible to analyze vibration on the oscillating body and one can observe no vibration mode shape during experiment. In case of the FEA method, it is difficult to define boundary conditions correctly if the shape of a body tested is complex, and one can just obtain vibration mode shapes on the peak amplitude in each modes. In this study, plane plate of stainless steel(STS304), isotropic material, that is used as structural steel is analyzed about vibration characteristics under tension. Also, in the study of stainless steel, the characteristics of composite material(AS4/PEEK) used as high strength structural material in aircraft is evaluated about vibration under tension, and studies the effect of tension on vibration.

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Open Intramedullary Nail with Tension Band Sutures on Proximal Humeral Fracture (상완골 근위부 골절에 시행한 긴장 대 봉합을 동반한 관혈적 골수강내 고정술)

  • Park, Jin-Young;An, Jin-Woo;Lee, Sung-Churl
    • Clinics in Shoulder and Elbow
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    • v.6 no.2
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    • pp.149-160
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    • 2003
  • Purpose: to determine the results after open intramedullary nailing and tension band suture technique in proximal humerus fracture for improving the stability and decreasing the complications. Materials and Method: Authors reviewed 27 patients treated by open intramedullary nailing and tension band suture technique. Mean follow-up period was 39 months (24-59months). Surgical neck fracture were 6 cases, surgical neck fracture with shaft fracture were 3 cases, three part fracture with greater tuberosity fracture were 17 cases, four part fracture was 1 case and fracture and dislocation were 2 cases Results: We got the bony union in 26 cases. Average pain scale was 1 point (0-6), Neer score was 86 point(45-99) and ASES score was 85 point(40-100). We separate all cases in two groups based on age (65 years), L-spine t-score (-2.5) and Neer classification (2 and 3 part). There is no significance in pain scale, Neer score and ASES score between each group. Conclusion: As a method of surgical treatment on severe proximal humeral fractures, we recommend intramedullary nailing and tension band suture technique and it may have particular advantages in early exercise and satisfactory functional outcome.

Properties of Low Density Foamed Concrete for Building Construction Using Anionic Surfactants of Synthetic and Natural Materials

  • Jeong, Ji-Yong;Kim, Jin-Man
    • Journal of the Korea Institute of Building Construction
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    • v.11 no.6
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    • pp.557-566
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    • 2011
  • The surfactants facilitate the formation of foam bubbles under a proper condition and provide stability of foam bubbles by decreasing the surface tension of solutions and increasing the viscosity of foam surface. However, there have been almost no practical data of foam concrete in this regard so far. This study aims to understand the effects of foaming agents such as anionic synthetic surfactant and anionic natural material surfactant on the low density foamed concrete. From the experiment, the vegetable soap of anionic natural material surfactants showed a higher foaming rate, more open pores, slightly lower compressive strength, and a higher permeability coefficient compared to the vegetable soap of anionic synthetic surfactants. It is believed that the natural material surfactants make not only the surface tension of the solution low but also the viscosity of slurry high.

Damage Estimation of Cables using PZT (압전소자를 이용한 케이블의 손상평가)

  • Park, Kang-Geun;Kim, Ie-Sung;Kim, Wha-Jung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.11a
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    • pp.235-239
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    • 2008
  • Cable systems are a construction of elements carrying only tension and no compression or bending in membrane structure. Tensile membrane structures are most often used as roofs as they can economically and attractively span large distances. But cable systems have weaknesses to vibration by earthquake, wind and vehicle loads. Damage detection of cable systems by using existing safety diagnosis is difficult to detect the characteristic change of overall structural action. If cable snaps are occurred to cable release and tear in tension structures, these are set up a vibration. So, we used piezo-electric materials, and The principle of operation of a piezoelectric sensor is that a physical dimension, transformed into a force, acts on two opposing faces of the sensing element. In this study, the development on test method of cable system is proposed and tested by tensile strength using piezo-electric materials.

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A study of the shear properties for hybrid composites (하이브리드 복합재료의 전단 물성치 측정에 관한 연구)

  • 백운철;조맹효;황재석
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.10a
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    • pp.96-99
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    • 2002
  • In order to determine the in-plane shear properties of unidirectional carbon fiber reinforced aluminum laminate composites, a new Iosipescu shear test fixture was developed, by using a fixture undergoing tensile force for the specimen edge to be subjected to compressive loads assumption, under plane stress. Also, to compare the results, Iosipescu shear test method by the modified Wyoming fixture and the off-axis tensile test were performed to determine the shear properties. Off-axis tension test was performed by using new oblique-shaped tabs proposed by Sun and Chung. [5] The oblique tabs reduced remarkably end-constraint effects of off-axis specimens with a aspect ratio of about eight. It is observed through the experimental results show that there is no significant difference between off-axis test results and those of Iosipescu shear test.

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Treatment of Fifth Metatarsal Base Fracture Using Tension Band Wiring (인장대 강선 고정술을 이용한 제5 중족골 기저부 골절의 수술적 치료)

  • Ahn, Jong-Kuk;Chung, Hyung-Jin;Bae, Su-Young;Park, Ji-Yong
    • Journal of Korean Foot and Ankle Society
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    • v.15 no.1
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    • pp.18-21
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    • 2011
  • Purpose: To evaluate the clinical and radiological results of internal fixation with tension band wiring for the fracture at the base of fifth metatarsal bone. Materials and Methods: From January 2008 to December 2009, 15 cases with displaced fracture at the base of fifth metatarsal were analyzed and average follow up period was 13.8 months. Lawrence classification was used to classify fracture type. We evaluated clinical results by American Orthopedic Foot Ankle Society (AOFAS) midfoot score and radiological results by union time. Complications was also checked. Results: According to classification, zone I fracture were 11 cases and zone II fracture were 4 cases. Bony union was achieved in all cases after 7 weeks. In the final follow-up, average AOFAS score was 94. There were no complications except hardware irritation. Conclusion: Satisfactory results were obtained after tension band wiring for the fifth Metatarsal base fracture in zone I fracture or comminuted zone II fracture for which it is not easy to be fixed with screw.

Studies on structural interaction and performance of cement composite using Molecular Dynamics

  • Sindu, B.S.;Alex, Aleena;Sasmal, Saptarshi
    • Advances in Computational Design
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    • v.3 no.2
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    • pp.147-163
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    • 2018
  • Cementitious composites are multiphase heterogeneous materials with distinct dissimilarity in strength under compression and tension (high under compression and very low under tension). At macro scale, the phenomenon can be well-explained as the material contains physical heterogeneity and pores. But, it is interesting to note that this dissimilarity initiates at molecular level where there is no heterogeneity. In this regard, molecular dynamics based computational investigations are carried out on cement clinkers and calcium silicate hydrate (C-S-H) under tension and compression to trace out the origin of dissimilarity. In the study, effect of strain rate, size of computational volume and presence of un-structured atoms on the obtained response is also investigated. It is identified that certain type of molecular interactions and the molecular structural parameters are responsible for causing the dissimilarity in behavior. Hence, the judiciously modified or tailored molecular structure would not only be able to reduce the extent of dissimilarity, it would also be capable of incorporating the desired properties in heterogeneous composites. The findings of this study would facilitate to take step to scientifically alter the structure of cementitious composites to attain the desired mechanical properties.