• Title/Summary/Keyword: Plastic spike

Search Result 12, Processing Time 0.027 seconds

Effect of Different Golf Shoe treads on Wear and Ball Speed of Putting Green (퍼팅그린의 마모와 골프공의 구름에 미치는 골프화의 영향)

  • 심포룡;심규열
    • Asian Journal of Turfgrass Science
    • /
    • v.11 no.3
    • /
    • pp.205-210
    • /
    • 1997
  • The metal spikes evaluated in this study significantly affected more negative on the turf wear and ball speed of putting green than alternative plastic spikes. 1.The metal spikes caused the most amount of wear compared with plastic spikes, athletic shoes and mountain-climbing shoes. On the other hand, athletic shoes caused the least amount of wear. Plastic spikes caused wear more than athletic shoes, hut apparently wear less than metal spikes. The wear from metal spike repaired later than any other tread types. 2.The wear from all kinds of shoe treads in wetcondition green were higher than in dry-condition green and the wear from metal spikes was more severe compared with plastic spikes in both green condition. 3. Ball speed of heavy compaction area by metal spike was reduced about 9% compared with that of light compaction area, hecause metal spikes made many holes in the putting green surface. On the other hand, plastic spikes did not affect hall speed of heavy and light compaction area in the putting green. Key words: Metal spike, Plastic spike, Wear, Ball speed.

  • PDF

A Comparative Study for Incompressibility of Rigid Plastic Finite Element Method (강소성 유한요소법에서 비압축성조건에 관한 비교 연구)

  • 이상재;조종래;배원병;김영호
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 1997.10a
    • /
    • pp.40-44
    • /
    • 1997
  • The governing functional in plastic deformation has to satisfy the incompressible condition. This incompressible condition imposed on the velocity fields can be removed by introducing either the Langrange multiplier or the penalty function into the functional. In the study two-dimensional rigid plastic FEM programs using by Lagrange multiplier and penalty function are developed. A compression of cylinder and a spike forging are simulated to compare the data of loads, local mean stresses and reductions of volume.

  • PDF

A Comparative Study for Incompressibility of Rigid Plastic Finite Element Method (강소성 유한요소법에서 비압축성조건에 관한 비교 연구)

  • 이상재;조종래;배원병;김영호
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 1997.10a
    • /
    • pp.57-61
    • /
    • 1997
  • The governing functional in plastic deformation has to satisfy the incompressible condition. This incompressible condition imposed on the velocity fields can be removed by introducing either the Langrange multiplier or the penalty function into the functional. In this study two-dimensional rigid plastic FEM programs using by Langrange multiplier and penalty function are developed. A compression of cylinder and a spike forging are simulated to compare the data of loads, local mean stresses and reductions of volume.

  • PDF

Hourglass Control in Rigid-Plastic Finite Element Analysis (강소성 유한요소해석에서 Hourglass Control)

  • Gang, Jeong-Jin;O, Su-Ik
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.20 no.4
    • /
    • pp.1290-1300
    • /
    • 1996
  • The finite element method, based on rigid-plastic formulation, is widely used to simulate metal forming processes. In order to improve the computational efficiency of the rigid-plastic FEM, one-point integration is used to evaluate the stiffness matrix with four-node rectangular elements and eight-node brick elements. In order to control the hourglass modes, hourglass strain rate components were introduced and included in the effective strain rate definition, Numerical tests have shown that the proposed one-point integration scheme reduces the stiffness matrix evaluation time without deteriorating the convergence behavior of Newton-Raphson method. Simulations of a ring compression, a plane-strain closed-die forging and the three-dimensional spike forging processes were carried out by using the proposed integration method. The simulation results are compared to those obtained by applying the conventional integraiton method in terms of the solution accuracy and computational efficiency.

Controlled Surface Functionalities of metals using Femtosecond Laser-induced Nano- and Micro-scale Surface Structures (펨토초 레이저 유도 나노 및 마이크로 구조물을 활용한 금속 표면 기능성 제어)

  • Taehoon Park;Hyo Soo Lee;Hai Joong Lee;Taek Yong Hwang
    • Design & Manufacturing
    • /
    • v.17 no.2
    • /
    • pp.55-61
    • /
    • 2023
  • With femtosecond (fs) laser pulse irradiation on metals, various types of nano- and micro-scale structures can be naturally induced at the surface through laser-matter interaction. Two notable structures are laser-induced periodic surface structures (LIPSSs) and cone/spike structures, which are known to significantly modify the optical and physical properties of metal surfaces. In this work, we irradiate fs laser pulses onto various types of metals, cold-rolled steel, pickled & oiled steel, Fe-18Cr-8Ni alloy, Zn-Mg-Al alloy coated steel, and pure Cu which can be useful for precise molding and imprinting processes, and adjust the morphological profiles of LIPSSs and cone/spike structures for clear structural coloration and a larger range of surface wettability control, respectively, by changing the fluence of laser and the speed of raster scan. The periods of LIPSSs on metals used in our experiments are nearly independent of laser fluence. Accordingly, the structural coloration of the surface with LIPSSs can be optimized with the morphological profile of LIPSSs, controlled only by the speed of the raster scan once the laser fluence is determined for each metal sample. However, different from LIPSSs, we demonstrate that the morphological profiles of the cone/spike structures, including their size, shape, and density, can be manipulated with both the laser fluence and the raster scan speed to increase a change in the contact angle. By injection molding and imprinting processes, it is expected that fs laser-induced surface structures on metals can be replicated to the plastic surfaces and potentially beneficial to control the optical and wetting properties of the surface of injection molded and imprinted products.

DEVELOPMENT OF MUSHROOM SPAWN BOTTLE CUTTER-SPAWM CAKE SHREDDER

  • Choe, Kwang-Jae;Chang, Yu-Seob;Yun, Jin-Ha
    • Proceedings of the Korean Society for Agricultural Machinery Conference
    • /
    • 1996.06c
    • /
    • pp.1031-1040
    • /
    • 1996
  • Spawn bottle cutting and spawn cake shredding machine has been developed to save the farm labor and operating cost for mushroom growing farmers. The prototype can cut the bottom and side of the bottle while shredding the spawn cake by one farmer. The cutting plastic shell is done by two couples of high speed disc saws that can cut cross section and lengthwise two side of the bottle, while spawn cake shredding is done by spike teethed rotating drum and wiremesh concave. The optimum speed of cutting disc saw was observed 1.700rpm both the cross cutting saw and lengthwise cutting saw in consideration of the cutting accuracy. And the location for the instalation of cross cutting disc saw was considered as around 4 mm above the table bottom , while the optimum clearance between two edges of lengthwise cutting disc saw was showed 86mm. For the sawdust spawn cake shredder , proper size of spawn sawdust granule was observed in the 15 x 15mm size withmesh concave with the shredding rum speed of 500rpm. The prototype can be reduce 73 per cent of working hours with the working cost reduction of 49 per cent compare with those of conventional operation.

  • PDF

The external benefit of combustible waste-to-energy: A contingent valuation study (가연성 폐기물 에너지화의 외부편익 : 조건부 가치측정법의 적용)

  • Lim, Seul-Ye;Kim, Ho-Young;Yoo, Seung-Hoon
    • Journal of Energy Engineering
    • /
    • v.22 no.3
    • /
    • pp.270-282
    • /
    • 2013
  • Combustible waste into energy policy is an effective method to respond to climate change and depletion of fossil fuels. Combustible waste into energy is the process of generating energy in the form of electricity and/or heat from the combustible waste such as vinyl, paper and plastic. This study tries to estimate the external benefit of enhancing the ratio of combustible waste into energy to primary energy from 1.89% to 5% using contingent valuation(CV) method. To this end, we report the results from a CV survey to elicit the willingness to pay (WTP) for combustible waste into energy. A CV survey of 500 households was conducted in the Seoul by using person-to-person interviews. Thus, the procedures of applying and the findings from the one-and-one-half bounded dichotomous choice spike model used to deal with the zero WTP responses are provided in the paper. The results show that the average WTP is estimated to be 2,724 won per household per month and statistically significant at the 5% level. Expanding the value to the Seoul gives us an aggregate value of 13.7 billion won per year.

Effects of Water Table Depth in Different Soil Texture on Growth and Yield of Barley and Wheat (토성별 지하수위가 밀, 보리의 생육 및 수량에 미치는 영향)

  • 이홍석;박의호;송현숙;구자환
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.40 no.2
    • /
    • pp.195-202
    • /
    • 1995
  • This experiment was performed to characterize the optimum water table level for the growth and yield of barley(var. Olbori) and wheat(var, Grumil), Olbori and Grumil were grown in the 550 liter plastic pot filled with silt loam or sandy loam, During the whole growth period, the water table adjusted to be 20, 30, 40, 50, and 70cm, Higher water table was resulted in the decrease in plant height and top dry weight, but in the increase of the ratio of top to root dry weight, especially in barley, This suggested that high water table level affected more the growth of top than that of root, The number and area of green leaves were decreased as the water table was higher than 30 to 40cm at the late growth period(May 18, 1993), The largest number and area of green leaves were shown at 50cm of water table in sandy loam and at 70cm in silt loam, As the water table was high, the leaf chlorophyll content was low, And barley was affected more significantly than wheat by soil texture, The photosynthetic activity was decreased remarkably at 20cm water table, Heading period was 2 to 3 and 4 days earlier at the 20cm water table of sandy loam in barley and wheat, respectively, However this earlier heading was not shown in silt loam, Grain filling was accelerated 5 to 7 days earlier in barley and 10 days in wheat grown at 20cm water table, The highest yield was present at 50 and 70cm water table, The yield was decreased remarkably at 20cm water table, resulting that yield reduction ratio of barley was 71.1% and 72, 2%, and that of wheat was 41.0% and 60, 0% in sandy loam and silt loam, respectively, High water table decreased the number of spike per unit area, but increased the seed weight per spike in barley, However, High water table reduced the seed weight per spike in wheat. There was significant correlation between yield and leaf chlorophyll content in wheat and barley, Yield was correlated significantly with green leaf area in barley, and with top dry weight, ratio of top to root dry weight chlorophyll content and photosynthetic activity in wheat. The optimum water table was 50 to 70cm in wheat and barley, They grew fairly well at 30cm water table of sandy loam, and at 40cm of silt loam.

  • PDF

A Study on Changes of Furniture Hard Ware in Korea - From the Joseon Era to Modern Times - (한국 가구 하드웨어 변화 연구 - 조선시대부터 현대까지 -)

  • Cho, Sook-Kyung;Moon, Sun-Ok
    • Journal of the Korea Furniture Society
    • /
    • v.23 no.2
    • /
    • pp.122-129
    • /
    • 2012
  • This article was intended as fundamental materials to recognize the current status of furniture hard ware in Korean market and to fix the identity of Korean furniture, by investigating and comparing the furniture hard ware used in the Joseon era and in modern times by type, function, shape and material. The analysis of furniture hard ware of the Joseon era and modern times from the view of functional aspects was oriented to the hard ware necessary to open and close the door & drawer on one side, and to that being attached to the main body of furniture not to scratch the wood by another wood on the other side, and from this the following conclusion was drawn. First of all, "Gwangdoojung" - a kind of spike- and metal decoration on the edge of the furniture disappeared, while the function-oriented hard wares have been diversified in modern times, from the perspective of the change of kinds. Second, the functional aspect of the furniture hard ware was emphasized in modern times than the Joseon era. In other words, the hard wares of the Joseon era came into view due to their strong appeal to decoration, whereas those of modern times were mostly hidden or moderated, keeping the function substantially. Third, the hard wares from the Joseon era were shown in concrete and detailed shape motivated by natural objects and furthermore even gloriously, but the modern hard wares are simple & basic geometry, from a formative point of view. Fourth, the material aspects present that the Joseon era's hard ware was mainly cast iron, whereas that of modern times shows the diversification from metal to even plastic. Finally, the recent trend in naming of the hard wares is the words of foreign origin. This resulted from that the foreign names of hard wares are valid also after import process in Korean market, so the domestic development of hard ware as the essential factor for the furniture design is urgently necessary to establish the identity of Korean modern furniture.

  • PDF

Determination of Peening Area for Finite Element Residual Stress Analysis of Ultrasonic Nanocrystal Surface Modification under Multiple Impact Conditions (초음파나노표면개질 다중충격 조건에서의 잔류응력 예측을 위한 유한요소 피닝해석 영역 결정)

  • Tae-Hyeon Seok;Seung-Hyun Park;Nam-Su Huh
    • Transactions of the Korean Society of Pressure Vessels and Piping
    • /
    • v.17 no.2
    • /
    • pp.145-156
    • /
    • 2021
  • Ultrasonic Nanocrystal Surface Modification (UNSM) is a peening technology that generates elastic-plastic deformation on the material surface to which a static load of a air compressor and a dynamic load of ultrasonic vibration energy are applied by striking the material surface with a strike pin. In the UNSM-treated material, the structure of the surface layer is modified into a nano-crystal structure and compressive residual stress occurs. When UNSM is applied to welds in a reactor coolant system where PWSCC can occur, it has the effect of relieving tensile residual stress in the weld and thus suppressing crack initiation and propagation. In order to quantitatively evaluate the compressive residual stress generated by UNSM, many finite element studies have been conducted. In existing studies, single-path UNSM or UNSM in a limited area has been simulated due to excessive computing time and analysis convergence problems. However, it is difficult to accurately calculate the compressive residual stress generated by the actual UNSM under these limited conditions. Therefore, in this study, a minimum finite element peening analysis area that can reliably calculate the compressive residual stress is proposed. To confirm the validity of the proposed analysis area, the compressive residual stress obtained from the experiment are compared with finite element analysis results.