• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2000.04b
• /
• pp.61-68
• /
• 2000

In general, the design of membrane structures takes three steps. The first is shape finding analysis which is determination of initial equilibrium geometry with uniform stresses. The second step involve the computation of the stress-deformation to get completed membrane under various load conditions. The third step is to divide the membrane structures into several plan strips from the initial equilibrium states. This procedure is needed because of the initial shape has usually undevelopable curved surface and is called as "cutting patterns generation". By introducing this work, the deformation due to the initial stress is removed and approximate cutting patterns are generated. In this approach, however, material properties is not considered, therefore the error between the design stresses and actual stresses during the fabrication of plan strips should be occurred. In this paper, actual equilibrium shape analysis procedure for HP shape models is presented. The deviations of stresses between the design stresses and actual stresses are estimated.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.11a
• /
• pp.158-159
• /
• 2015

Architectural fabrics are now used in membrane structure with the merits of free shape, lightness and opened up new possibility for the design of new building structures. Recently PVC, PVF, PVDF, PTFE coated fabric for using the membrane structures. However, clear standards for the design and construction is not exist because of the lack of Architectural fabric research. In this paper, Flammable properties of PVDF, PTFE coated fabrics are obtained through the Flammability test using the Cone Calorimeter. Based on these results, identify the fire resistance property of the Architectural fabric.

• 월간 기계설비
• /
• s.306
• /
• pp.87-93
• /
• 2016

중소기업청은 지난 해 12월 30일 '중소기업자간 경쟁제품 지정내역 및 공사용 자재 직접구매 대상품목'을 개정하고 올해 1월 1일부터 3년(2018.12.31)간 적용에 들어갔다. 개정된 공사용 자재 직접구매 대상품목 중 그동안 대한기계설비건설협회(회장 이상일)가 지정 제외를 위해 총력을 기울였던 고무발포단열재가 기존 공사용자재 직접구매 대상품목 중에서 유일하게 제외됐다. 새로 개정된 공사용 자재 직접구매 대상품목은 고무발포단열재, 애자, 공기살균기, 플라스틱포대 등 4개 품목이 빠지고 신규 지정을 신청한 12개 품목 중 8개(커튼, 차양, 볼라드, 잡석, 데이터 포트장치, 디지털영상 정보 안내시스템, 막구조물, 포설형 탄성 포장재)만 채택돼 총 127개 품목으로 확정됐다. 고무발포단열재가 공사용 자재 직접구매 대상품목에서 제외됨으로써 앞으로 기계설비건설업계의 매출 신장과 생산성 향상에 크게 기여할 것으로 기대되고 있다.

• Proceeding of KASS Symposium
• /
• 2005.05a
• /
• pp.89-98
• /
• 2005

Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The material property of the membrane has strong axial stiffness, but little bending stiffness. Therefore membrane structures arc unstable structures initially. These soft structures need to be introduced initial stresses first because of its initial unstable state, and it happens large deformation phenomenon. To find the structural shape after large deformation caused by initial stiffness introduced, we need the shape analysis considering geometric nonlinearity in structural design procedure. In this study, we investigate into the stress concentration at crack of membrane structures. Therefore, using the nonlinear analysis program that NASS (Nonlinear Analysis for Spatial Structures) perform nonlinear analysis, and stress distribution for creak length investigate for using linear elastic fracture mechanics.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2016.05a
• /
• pp.149-150
• /
• 2016

The membrane structure is being applied in structures for various uses for its many advantages as permeableness, lightweightness, constructability, resource saving, and management cost reduction, and the usage is being expanded. However, despite the development of membrane structure, the standard for architectural membrane performance that considered fire safety is still inadequate. Therefore, this study applied basalt fiber with flame resistance on architectural membrane. Also, this study confirmed the membrane applicability of basalt fiber through comparison with existing architectural membrane.

• Journal of Korean Association for Spatial Structures
• /
• v.1 no.1 s.1
• /
• pp.157-166
• /
• 2001

In general, the cutting pattern of the membrane structures is determined by dividing the complicated curved 3-D surface into several 2-D plane strip by using flattening technique. In this procedure, however, some discrepancies ore occurred between actual stresses of equilibrated state and designed uniform stresses because the material properties are not considered. These deviations can cause the critical structural problems, wrinkling or overstress, and thus a optimization process should be considered. In this paper, a new analytical method for determining an optimum cutting pattern considering material properties is presented. Here, iterative procedure is introduced to decrease the errors caused in numerical process. The optimization method proposed can diminish the deviations occurred by material properties and numerical errors, simultaneously. As a results, it is shown that the final stress distributions for the HP shell model are sufficiently near to design stress distributions, and it can be concluded that this method can be used to obtain the optimized cutting pattern of membrane structures.

• Journal of Korean Association for Spatial Structures
• /
• v.8 no.5
• /
• pp.95-105
• /
• 2008

The objective of this study is find out the stressed condition, slipped direction and slipped dimension when some elements of cable-membrane structures are slipped from it's initially designed coordinates by external loads as wind or non uniform load and so on. In order to search the slipped behaviors of cable-membrane structures, a ALE finite element formulation is introduced. In these procedures, a stiffness matrix related with ALE concept is formulated and a FE analysis program for cable-membrane structures with slipped elements is developed.

• Proceeding of KASS Symposium
• /
• 2006.05a
• /
• pp.205-213
• /
• 2006

Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The design procedure of membrane structures are needed to do shape finding, stress-deformation analysis and cutting pattern generation, because the material property has strong axial stiffness, but little bending stiffness. The problem of cutting pattern is highly varied in their size, curvature and material stiffness. So, the approximation inherent in cooing pattern generation methods is quite different. Therefore the ordinary computer software of structural analysis & design is not suitable for membrane structures. In this study, we develop the program for cutting pattern generation using geodesic line, and investigate the result of example's cutting pattern in detail.

• Proceeding of KASS Symposium
• /
• 2008.05a
• /
• pp.171-178
• /
• 2008

This paper is concerned with the development of a measurement system using field measuring device which will give the membrane stress of the membrane structures. Up to this point, several techniques on measurement of membrane stresses has been proposed and some have been used in the fields, but accuracy of the measured stresses to be far from reliable one. Such situation has not been changed until recent days, we do not have the measurement device on which we can depend. On top of that, due to the different properties in cross directions for material of the membrane, the stress in the warp direction is different from that in the fill one. A new method is proposed to measured membrane stresses in two different direction separately, where instead of membrane stresses directly, an external force perpendicular to the membrane to be applied. A portable device can measure the applied force and the displacement. A special testing bed to be fabricated to accommodate $50cm{\times}50$ manbrane specimen which can apply 5 ton load in two orthogonal direction. A special device using push-pull gage was developed. To measure the membrane stresses in warp and fill direction separately, a different length of the tips are used. The measuring device which can called tension meter, can be calibrated on the testing bed, and optimized the length and shape of tip.

• Journal of Korean Association for Spatial Structures
• /
• v.16 no.1
• /
• pp.35-42
• /
• 2016

Until recently, almost all ETFE film structures that have been erected is the cushion type because there are problems at lower allowable strength under elastic range and viscosity behaviour such as creep and relaxation of ETFE films under long-term stresses. But the number of tension type structures is currently increasing. This paper proposes the stretch fabrication of ETFE film to verify the applicability of ETFE films to tensile membrane structures. First of all, to investigate the possibility of application on tensile membrane structures, the stretch fabrication test is carried out, and it is verified that it is possible to increase the yield strength of the film membrane structures. After simulating the experiment also carries out an analytical investigation, and the effectiveness of the elasto-plastic analysis considering the viscous behavior of the film is investigated. Finally, post-aging tension measurement is conducted at the experimental facilities, and the viscosity behavior resulting from relaxation is investigated with respect to tensile membrane structures.