• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.5
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• pp.10-21
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• 2006

For analyze of the bearing capacity, skin friction and settlements of pile on axial compressive loading, both Load transfer tests of pile and pile loading test in field have application to commonly before pile installing. A bearing capacity of pile was affected by the characteristics of surrounding ground of pile. Especially, that is very different because of evaluation of settlement due to each soil conditions of ground depths. The ground characteristics using evaluation of bearing capacity of pile through load transfer analysis depends on N values of SPT, and then a bearing capacity of pile installed soft ground and refilled area may be difficult to rational evaluation. An evaluation of bearing capacity on pile applied axial compressive loading was effected by strength of ground installed pile, unconfined compressive strength at pile tip, pile diameter, rough of excavated surface, confining pressure and deformation modules of rock etc and these are commonly including the unreliability due to slime occurred excavation works. Load transfer characteristics considered ground conditions take charge of load transfer of large diameter pile was investigated through case study applied load transfer tests. To these, matrix analytical technique of load transfer using finite differential equation developed and compared with the results of pile load test.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.1
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• pp.83-86
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• 2014

Many have been performed to decrease the thickness of polyethylene terephthalate (PET) bottles to reduce the manufacturing cost. However, it is difficult to guarantee the mechanical strength under top-loading after decreasing the thickness. This paper investigates the large deformation characteristics of a PET bottle under a compressive load using experimental and finite element analysis (FEA) data. A round 1.65-L bottle is analyzed under a compressive velocity of 5 mm/min with a maximum load of 9,800 N in experiments. The arc length method is used in a nonlinear FEA to understand the buckling phenomenon of the PET bottle. From the analyzed results, a recommendation is made to restrict the top loading to less than 1,208 N, because the first buckling phenomenon occurred at a load of 1,208 N.

• Journal of the Korean Society of Safety
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• v.23 no.4
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• pp.67-71
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• 2008

Formwork is a temporary structure that supports its weight and that of fresh concrete as well as construction live loads. Slab formwork consists of sheathing, stringer, hanger and shore. In construction site, pipe supports are usually used as shores which are consisted of the slab formwork. In this study, compressive strength of 80 pipe supports was measured by knife edge test and plate test. Buckling load of pipe supports was analyzed by structural analysis program(MlDAS). Theoretical buckling load with/without initial deformation was got by theoretical analysis. According to these results, buckling load which was analyzed by structural analysis program(MlDAS) was larger than compressive strength of knife edge test and plate test. Theoretical buckling load without initial deformation was larger than compressive strength of knife edge test and plate test. But Theoretical buckling load with initial deformation was lower than compressive strength of knife edge test and plate test. Initial deformation equation for test method according to the pipe support length was suggested. Therefore, the present study results will be used to design the slab formwork safely.

• Tunnel and Underground Space
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• v.5 no.2
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• pp.144-154
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• 1995

In this paper, we make a study on comparison and evaluation of the seoul granite properties, which are unit weight, uniaxial compressive strength, Brazilian tensile strength and, point load strength. The typical result are as follow- 1. From the measured value of point load strength anisotropy index, the seoul granite is considered to be homogeneous. 2. There is a linear relationship between uniaxial compressive strength and size corrected point load strength index. 3. Brazilian tensile strength and size corrected point load strength index are closely tied together.

• Proceedings of the Korea Concrete Institute Conference
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• 1992.10a
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• pp.167-172
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• 1992

To analyze the effects compressive strength of concrete and longitudinal steel ratio on second-order moment of columns, 30tied rein reinforced concrete columns with hinged ends were tested. The 80mm square cross section was used and the amount of eccentricity was 24mm. The compressive strengths of column specimens with slenderness ratios of 10, 60, and 100were 250, 648 and 880kg/$\textrm{cm}^2$, and the longitudinal steel ratios were 1.98%(4-D6) and 3.95%(8-D6). The ratio of ultimate load capacity to that of short column with the same eccentricity (Pu/Pn) was much decreased at high slenderness ratio with increasing the compressive strength of concrete. And the lateral displacement of slender column at the ultimate load was decreased as the strength was increased. These are due to that at high slenderness ratio the load capacity and behavior of column are affected by flexural rigidity. And, it was also found that with increasing steel ratio, the value of Pu/Pn and the lateral displacement at the ultimate load were larger for the same slenderness ratio.

• Journal of Korean Association for Spatial Structures
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• v.17 no.1
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• pp.59-67
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• 2017

In this study, load transfer tests based on KCI-PS101 were conducted to verify the performance of spiral anchorage zone reinforcement for banded post-tensioning (PT) monostrands. With results, the compressive strength of spiral reinforcement was increased by about 20% than that of specimens with two horizontal steel bars and 8% than that of U-shaped bars. Advanced spiral reinforcement for corner increases compressive strength and can resist the spalling forces or fall-out effect at the corner by shear. The ratio of maximum load to amount of steel of the spiral reinforcement is about twice than that of U-shaped reinforcement. With increase of compressive strength capacity and improvement of constructability, the spiral reinforcement is considered to have advantages of promoting the performance of PT anchorage zone compared to conventional methods.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.4
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• pp.253-257
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• 2016

The effects of re-peening on the compressive residual stress and fatigue life of Al7075-T6 were investigated. The compressive residual stress induced on the surface of components by shot peening is known to increase the fatigue life. However, the fatigue load relaxes the compressive residual stress of components. Re-peening is a technique to again induce the relaxed compressive residual stress and increase the total fatigue life of components. In this study, the re-peening process was applied to fatigue-loaded specimens. The compressive residual stress and fatigue life were examined for re-peened specimens with fatigue ratios of 30%, 50%, and 70%. The results showed that the compressive residual stress of the specimens was relaxed under the fatigue load. The re-peening process significantly increases the compressive residual stress and total fatigue life.

• Journal of the Korean Society for Railway
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• v.13 no.1
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• pp.31-36
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• 2010

The objective of this study is to evaluate effects of honeycomb cell size for compressive behaviors of square sandwich composite tubes with woven fabric carbon/epoxy skin and Al honeycomb core. In order to achieve these goals, four different kinds of tubes were fabricated and compressed to 200mm~250mm under quasi-static load of 10mm/min. The Al honeycombs with cell size of 6.35mm and 9.53mm were used. The relationship of mean compressive load and cell size was evaluated. In addition, the effect of peel strength and equivalent elastic modulus in ribbon direction for the mean compressive load was investigated.

• Structural Engineering and Mechanics
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• v.45 no.1
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• pp.129-144
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• 2013

Load-carrying capacity of combined members consisted of inner and sleeved tubes subjected to axial compression was investigated in this paper. Considering the initial bending of the inner tube and perfect elasto-plasticity material model, structural behavior of the sleeved member was analyzed by theoretic deduction, which could be divided into three states: the elastic inner tube contacts the outer sleeved tube, only the inner tube becomes plastic and both the inner and outer sleeved tubes become plastic. Curves between axial compressive loads and lateral displacements of the middle sections of the inner tubes were obtained. Then four sleeved members were analyzed through FEM, and the numerical results were consistent with the theoretic formulas. Finally, experiments of full-scale sleeved members were performed. The results obtained from the theoretical analysis were verified against experimental results. The compressive load-lateral displacement curves from the theoretical analysis and the tests are similar and well indicate the point when the inner tube contacts the sleeved tube. Load-carrying capacity of the inner tube can be improved due to the sleeved tube. This paper provides theoretical basis for application of the sleeved members in reinforcement engineering.

• Smart Structures and Systems
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• v.26 no.5
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• pp.605-617
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• 2020

In this study, the experimental tests for the direct tensile strength measurement of Ultra-High Performance Concrete (UHPC) were numerically modeled by using the discrete element method (circle type element) and Finite Element Method (FEM). The experimental tests used for the laboratory tensile strength measurement is the Compressive-to-Tensile Load Conversion (CTLC) device. In this paper, the failure process including the cracks initiation, propagation and coalescence studied and then the direct tensile strength of the UHPC specimens measured by the novel apparatus i.e., CTLC device. For this purpose, the UHPC member (each containing a central hole) prepared, and situated in the CTLC device which in turn placed in the universal testing machine. The direct tensile strength of the member is measured due to the direct tensile stress which is applied to this specimen by the CTLC device. This novel device transferring the applied compressive load to that of the tensile during the testing process. The UHPC beam specimen of size 150 × 60 × 190 mm and internal hole of 75 × 60 mm was used in this study. The rate of the applied compressive load to CTLC device through the universal testing machine was 0.02 MPa/s. The direct tensile strength of UHPC was found using a new formula based on the present analyses. The numerical simulation given in this study gives the tensile strength and failure behavior of the UHPC very close to those obtained experimentally by the CTLC device implemented in the universal testing machine. The percent variation between experimental results and numerical results was found as nearly 2%. PFC2D simulations of the direct tensile strength measuring specimen and ABAQUS simulation of the tested CTLC specimens both demonstrate the validity and capability of the proposed testing procedure for the direct tensile strength measurement of UHPC specimens.