• Transactions of Materials Processing
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• v.30 no.3
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• pp.149-156
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• 2021

Fine blanking is a high-precision process combining principles of metal stamping and cold forming. Unlike conventional metal stamping, fine blanking uses a special triple action such as V-ring force, counter force, shearing force. This study performed the effect of pocket-shaped compression molding on the mold life of the fine blanking using the 7.4mm thick SM45C material. In order to determine the lifespan of the punch and die in the fine blanking molds, a trial mold was manufactured and various punch materials were selected to perform the mold life test. A study on the life of a fine blanking mold by applying a thick plate material was experimentally performed through a mold test.

• Geomechanics and Engineering
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• v.35 no.5
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• pp.465-473
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• 2023

The higher order shear deformable model and an exact analytical method is used for analytical bending analysis of a cylindrical shell subjected to mechanical loads, in this work. The shell is modelled using sinusoidal bivariate shear strain theory, and the static governing equations are derived using changes in virtual work. The eigenvalue-eigenvector method is used to exactly solve the governing equations for a constrained cylindrical shell The proposed kinematic relation decomposes the radial displacement into bending, shearing and stretching functions. The main advantage of the method presented in this work is the study of the effect of clamping constraints on the local stresses at the ends. Stress, strain, and deformation analysis of shells through thickness and length.

• Earthquakes and Structures
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• v.10 no.5
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• pp.1033-1048
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• 2016

An analytical solution based on the neutral surface concept is developed to study the free vibration behavior of simply supported functionally graded plate reposed on the elastic foundation by taking into account the effect of transverse shear deformations. No transversal shear correction factors are needed because a correct representation of the transversal shearing strain obtained by using a new refined shear deformation theory. The foundation is described by the Winkler-Pasternak model. The Young's modulus of the plate is assumed to vary continuously through the thickness according to a power law formulation, and the Poisson ratio is held constant. The equation of motion for FG rectangular plates resting on elastic foundation is obtained through Hamilton's principle. Numerical examples are provided to show the effect of foundation stiffness parameters presented for thick to thin plates and for various values of the gradient index, aspect and side to thickness ratio. It was found that the proposed theory predicts the fundamental frequencies very well with the ones available in literature.

• Geomechanics and Engineering
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• v.15 no.6
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• pp.1193-1205
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• 2018

A footing located on slopes possess relatively lower bearing capacity as compared to the footing located on the level ground. The bearing capacity further reduces under seismic loading. The adverse effect of slope inclination and seismic loading on bearing capacity can be minimized by proving sufficient setback distance. Though few earlier studies considered setback distance in their analysis, the range of considered setback distance was very narrow. No study has explored the critical setback distance. An attempt has been made in the present study to comprehensively investigate the effect of setback distance on footing under seismic loading conditions. The pseudo-static method has been incorporated to study the influence of seismic loading. The rate of decrease in seismic bearing capacity with slope inclination become more evident with the increase in embedment depth of footing and angle of shearing resistance of soil. The increase in bearing capacity with setback distance relative to level ground reduces with slope inclination, soil density, embedment depth of footing and seismic acceleration. The critical value of setback distance is found to increase with slope inclination, embedment depth of footing and density of soil. The critical setback distance in seismic case is found to be more than those observed in the static case. The failure mechanisms of footing under seismic loading is presented in detail. The statistical analysis was also performed to develop three equations to predict the critical setback distance, seismic bearing capacity factor ($N_{{\gamma}qs}$) and change in seismic bearing capacity (BCR) with slope geometry, footing depth and seismic loading.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.1
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• pp.144-153
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• 2001

The effect of crosslinking on hand of the cellulase treated Tencel fabrics was investigated. Tencel fabrics were crosslinked with DMDHEU, mechanically prefibrillated, hydrolyzed by cellulase, and treated with softener. The treated fabrics were characterized by add-on, weight loss, DP rating, WRA, strength, SEM analysis and hand measurement. As DMDHEU concentration increased, weight loss of DMDHEU/cellulase treated fabrics decreased. However, cellulase treatment decreased DP properties and strength retention. Less fibrils were observed in the cellulase treated fabrics after DMDHEU treatment than the cellulase treated ones. It was confirmed that crosslinking with DMDHEU treatment was effective to control fibrillation. At 5% of DMDHEU concentration, DMDHEU/cellulase treated fabrics showed softer, smoother and bulkier hand compared with other treated fabrics. Among mechanical properties, bending and shearing properties were decreased progressively through DMDHEU, cellulase, and softener treatment. DMDHEU treatment contributed to impart resilience, cellulase treatment to bulkiness and softener treatment to smoothness. As the treatment of DMDHEU, cellulase, and softener progressed NUMREI, FUKURAMI, and THV increased with the exception of KOSHI.

• Journal of Biosystems Engineering
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• v.25 no.1
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• pp.1-10
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• 2000

This study was conducted to develop the mathmatical model for predicting the side thrust which is generated by the shearing action on the vertical surfaces of the sides of the track. Experiments were conducted with the three different shear plates with grouser length of 1, 3 and 5 cm for two different soil condition using soil bin system. The measured side thrust were compared with the values predicted by the new model developed in this study and by Bekker's model respectively. The values of side thrust predicted by the new model were more close to the measured values than those of the side thrust predicted by Bekker's model . The total thrust measured were also compared with the values predicted by the conventional model which considers only bottom thrust effect and by the new model which contains not only bottom thurst but side thrust effect. The values of the thrust predicted by conventional modelwere lower than measured values for both of the soil conditions and the three levels of grouser length. The maximum errors of conventional model were increased with the increase of grouser length. but the values of the total thrust predicted by the model developed in this study were well matched to the measured ones for both of the soil conditions and the three levels of grouser lengths.

• Tribology and Lubricants
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• v.4 no.1
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• pp.43-55
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• 1988

A Study on the effect of the additives in lubricating oil was investigated on the basis of the thermal activated wear theory in terms of their wear behaviours, using four ballwear machine. The sample oils, which included diethyl-3, 5-di-t-butyi-4-hydroxy-benzyl phosphonate (DEP), ZDDP and TCP additives respectively, showed distinct wear characteristics depending upon the bulk oil temperature and the sliding velocity. The newly synthesized additive, viz., DEP showed excellent antiwear performance cornpared with the conventional additives, ZDDP and TCP. On the basis of the experimental results, it is reduced that the wear mechanism of the conventional additives, viz., ZDDP and TCP is the protective film formation and their antiwear capability is depending upon the shearing strength of the film formed. On the other hand, the new additive, DEP showed that the secondary activation energy was much eliminated and so, the thermal instability was reduced by the hydrogen scavenging reaction of the new additive, which was virtually an endothermic reaction process.In conclusion, a new concept of antiwear mechanism is estabilished and testified. And new chemical, which showed the function of hydrogen and free radical scavenging role, is synthesized and introduced as the new, highly antiwear effective lubricating oil additive.

• Fibers and Polymers
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• v.6 no.2
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• pp.169-173
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• 2005

Low temperature plasma (LTP) treatment was applied to wool fabric with the use of a non-polymerizing gas, namely oxygen. After the LTP treatment, the fabric properties including low-stress mechanical properties, air permeability and thermal properties, were evaluated. The low-stress mechanical properties were evaluated by means of Kawabata Evaluation System Fabric (KES-F) revealing that the tensile, shearing, bending, compression and surface properties were altered after the LTP treatment. The changes in these properties are believed to be related closely to the inter-fiber and inter-yam frictional force induced by the LTP. The decrease in the air permeability of the LTP-treated wool fabric was found to be probably due to the plasma action effect on increasing in the fabric thickness and a change in fabric surface morphology. The change in the thermal properties of the LTP-treated wool fabric was in good agreement with the above findings and can be attributed to the amount of air trapped between the yams and fibers. This study suggested that the LTP treatment can influence the final properties of the wool fabric.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.8
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• pp.1153-1164
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• 2004

The purpose of this study was to knitted nine kinds of single knit and examined mechanical properties and hand to provide the fact that knit, tuck and miss stitch applied to various structure have an effect on hand of weft knitted fabrics. It was good to use tuck stitch rather than miss stitch to increase elasticity of knitted fabrics. As tuck stitch and miss stitch were double or triple overlaps, tensile resilence(RT) decreased by increase of friction contacted among stitch. As cross tuck stitch and cross miss stitch were knitted double or triple, bending rigidity(B), hysteresis of bending moment(2HB) and shearing(G) properties increased by jamming of stitch. As tuck stitch and miss stitch were overlap, thickness increased and they became thicker than miss stitch. Also, as they became thicker by these tuck stitch and miss stitch, compressional energy(WC) increased. It appeared that coefficient of friction(MIU) of cross tuck stitch was larger than coefficient of cross miss stitch. Mean deviation of surface roughness(SMD) had a tendency to be larger as tuck stitch and miss stitch increased. As cross tuck stitch and cross miss stitch were overlaps double or triple, KOSHI and FUKURAMI increased, total hand value(TIV) and NUMERI appeared high in double cross tuck stitch and double cross miss stitch.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.12
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• pp.54-59
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• 2001

The stability of a thin plate structure is very crucial problem which results buckling. Because the buckling strength of thin plates is lower than the yield strength of the material, reinforcement plate must be used to increase the buckling strength. And, in this case, spot welding is commonly used, however, the spot welded joints are practically designed by experimental decisions, so it is Inefficient and has the risks of buckling demolition. In this study, two parameters, such as the area ratio and the distance ratio of spot welding which have influence on the buckling strength, should be chosen. Under compressive and shearing load, the effect of two parameters on the critical stress is discussed.