• Title/Summary/Keyword: compaction control

Search Result 166, Processing Time 0.031 seconds

Yield and Compaction Behavior of Rapidly Solidified AI-Si Alloy Powders (급속응고 Al-Si 합금 분말의 항복과 압축거동)

  • 김형섭;장기태;조성석;천병선
    • Transactions of Materials Processing
    • /
    • v.6 no.2
    • /
    • pp.145-151
    • /
    • 1997
  • In order to obtain high quality products in powder metallurgy, it is important to control and understand the densification behavior of metal powders. The effect of the characters of powders on the compaction behavior was studied in this study by using three types of powders produced by the gas atomization, the centrifugal atomization and the twin roll-pulverization. The shape of the powders was a major factor in the apparent or tap density, and the deformation resistance of the matrix of the powders was a major factor in compactibility. Han's yield function (eq.2) for metal powders was simplified from the relationship based on the experimental results of copper powders. In spite of some assumptions, the calculated compaction curves using a new yield functionw was in accordance with the experimental results.

  • PDF

A Global Compaction of Microprograms Using Triangular Matrices and Junctiuon Blocks (삼각행렬과 접합블럭을 이용한 마이크로프로그램의 광역적 최적화)

  • Choi, Ki Ho;Lim, In Chil
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.23 no.5
    • /
    • pp.681-691
    • /
    • 1986
  • To represent the relations of the data dependency and resource conflict among micro-operations(MOP's) in the compaction process of microprograms, we propose a DDM (data dependent matrix) representation method instead of the DAG (conventional directed acyclic graph). Also, we propose a global compaction algorithm of microprograms to prevent a kind of block copying by cutting the trace at a junction block. The DDM method and compaction algoristhm have been applied to the Lah's example. The results shows that the proposed algorithm is more efficient than the conventional algorithms in reducing in reducing the total execution time and control memory space.

  • PDF

Effect of the Hopper of the Plug Transplanter and Moisture Content, Compaction Method, and Initial Irrigation of the Soil on the Seedling Survival rate at Transplant of Plug Seedling (플러그묘 정식시 정식기의 호퍼 크기, 토양수분, 초기관수량 및 진압방법이 작물에 미치는 영향)

  • 문성동;민영봉;박중춘
    • Journal of Bio-Environment Control
    • /
    • v.6 no.4
    • /
    • pp.258-263
    • /
    • 1997
  • The result was summarized of basic test and field test to find what quantity of irrigation, what state of compaction and what size of transplanting hopper could induce the optimum taking root in the transplantation of plug seedling by transplanters, and thus acquired the basic data for the development of the related transplanters and the optimum growth and development control. Livability of vegetables after transplanting had no significant difference with respect to for the size of hopper, but was greatly affected by the length of seedlings. The longest possible length of seedling for transplanting and optimal length were found to be 30cm and 28cm, respectively. For irrigation when transplanting red pepper or Chinese cabbage it was thought that large-sized hopper was appropriate. The livability of plug seedling 10 days after transplantation was mainly affected by soil moisture content. Consequently it was thought no irrigation would be needed when transplanting at the soil moisture content of more than 18% ; irrigation of more than 50cc would be needed at the soil moisture content of 13% : initial irrigation of more than 100cc and subsequent irrigation would be needed at the soil moisture content of less than 3.8%. The improvement of soil compaction method (left and right side compaction) with conventional semi-automatic transplanter was not necessary, since there was no difference in livability depending on the compaction methods, left-right side compaction or back-forth-left-right side compaction.

  • PDF

A Development on the Non-Destructive Testing Equipment for the Compaction Control and the Evaluation of Pavements Properties (지반물성추정 및 다짐관리를 위한 비파괴시험장비의 개발)

  • 최준성;김인수;유지형;김수일
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2000.11a
    • /
    • pp.385-390
    • /
    • 2000
  • In this study, the Non-Destructive Testing Equipment was introduced for the compaction control and the evaluation of pavements properties and the developing process was showed. Falling Weight Deflectometer(FWD) is a system for performing non-destructive testing of pavement and the other foundation structures. The system develops forces from the acceleration caused by the arrest of a falling weight and these forces are transmitted onto the surface of a structure causing it to deflect much as it would due to the weight of a passing wheel load. The structure will bend downward and exhibit a deflection basin. FWD uses a set of velocity sensors to determine the amplitude and shape of the deflection basin. The deflection response, when related to the applied loading, can provide information about the strength and condition of the various elements of the test structure. In this study, a computer program was developed that can be used to evaluate pavement and foundation structures from the data produced by FWD. The Falling Weight Deflectometer, non-destructive testing equipment, is increasing used at the whole world.

  • PDF

Electronic Circuit System of a Portable Rl Gauge for Compaction Control (성토다짐용 휴대용 Rl 계기의 전자회로 시스템)

  • 김기준
    • Journal of Korea Society of Industrial Information Systems
    • /
    • v.4 no.2
    • /
    • pp.32-38
    • /
    • 1999
  • In this study, an objection is to develop a electronic circuit of a gauage using radioisotope for compaction control to be needed at public works The developed gauage makes use of radioisotope with the activity exempted from domestic atomic law and consists of measuring circuits for gamma-rays and thermal neutrons, a high voltage supply unit and a microprocessor. To obtain meaningful numbers of pulse counts, parallel five and tow circuits are provided for gamma-rays and thermal neutrons, respectively. Also, to minimize effects of natural environmental radiation and electrical noise, circuits are electrostatically shielded and pulses made by ripples are eliminated by taking frequency of high voltage supplied to the circuit and pulse height of ripples into consideration One-chip microprocessor is applied to process various counts, results are stored, Enough and meaningful numbers of pulses are counted with the prototype gauage for compaction control.

  • PDF

Investigation on the Repeatability of Modified Proctor Test for Roller Compacted Concrete Pavement (롤러 전압 콘크리트 포장을 위한 수정다짐시험의 반복재현성 고찰)

  • Hwang, Seok Hee;Rith, Makara;Hong, Seong Jae;Lee, Seung Woo
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.35 no.4
    • /
    • pp.931-940
    • /
    • 2015
  • Roller Compacted Concrete Pavement (RCCP), is a type of pavement using compaction roller and asphalt finisher on concrete mixture that contains low amount of water. RCCP strength and durability are greatly affected by compaction level. Quality control is performed by ensuring the degree of compaction at site based on dry density. In the field, Modified Proctor Test is used in order to obtain optimum dry density. However, there is no clear compaction curve analysis criteria of Modified Proctor Test for RCCP. In this study, compaction curve built by three samples of Modified Proctor Test was produced and it was used to compare with compaction curve contented lower number of samples (one and two samples) in order to analyze their reliability. Thus, a conclusion was drawn from the results; by comparing to the result from Modified Proctor Test of three samples, the use of two samples represented result with only 0.5% of error which means the reliability is 99.5%.

A Study on the Evaluation of the Effect of the Ground Improvement of Reclaimed Land Based on Dynamic Compaction Method (동다짐 공법이 적용된 준설매립지반의 개량효과 평가에 관한 연구)

  • Kim Jong-Kook;Chae Young-Su
    • Journal of the Korean Geotechnical Society
    • /
    • v.22 no.5
    • /
    • pp.13-26
    • /
    • 2006
  • The purpose of this study is to examine the method of liquifaction potential occuring at the reclaimed land in Incheon district and to compare the result obtained by the method based on the earthquake of 6.5 magnitude. In addition, the effects of ground improvement and liquifaction potential were evaluated on the basis of SPT and CPT, which have been performed before and after the compaction pilot test. As a result, we realized that the bigger the energy of dynamic compaction test was, the better effect we got. After the dynamic compaction test, as the strength of ground increased, the safe factor also increased. It was evaluated that the method of dynamic compaction improved the seismic performance. Accordingly, the method of the quality control of reclaimed land based on dynamic compaction method was presented.

Prediction of the Elastic Modulus of Improved Soil Using the Flat TDR System (판형 TDR 시스템을 이용한 개량지반의 탄성계수 예측)

  • Song, Minwoo;Kim, Wanmin;Kim, Daehyeon;Choi, Chanyong
    • Journal of the Korean Geosynthetics Society
    • /
    • v.15 no.3
    • /
    • pp.77-85
    • /
    • 2016
  • This study was conducted to solve the problem such as damage of completed compaction ground using the conventional compaction control method. In this study, a TDR system equipped with a flat type probe has been developed. Also, the Piezoelectric stack, which is an instrument for measuring the elastic wave on the ground, has been added to the developed flat type probe. In this study, the strength variation of reinforced soil with time was determined by using the TDR system. The value of compression and shear modulus increased from 198.65MPa to 541.80MPa and from 125.55MPa to 302.02MPa with time, respectively. Based on the test results, it has been confirmed that the developed TDR system can be used as reinforced effect analysis of soil and compaction control.

A Study on Various Soil Stiffness Evaluation Methods with Field Test (현장시험을 통한 다양한 지반강성 평가방법에 대한 연구)

  • Yoo, Wan-Kyu;Kim, Byoung-Il;Kim, Ju-Hyong;Park, Keun-Bo
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.11 no.4
    • /
    • pp.1373-1380
    • /
    • 2010
  • The plate loading test(PLT) and the field density test are mainly used on the construction of embankments to control the compaction of a limited layer thickness. These two test methods are very time consuming and inefficient, but they are still commonly used as the methods of quality control for soil compaction. In the last 3 decades, many devices such as geogauge, light falling weight deflectometer(LFWD) and dynamic cone penetrometer(DCP) etc., have been introduced into the engineering market with the objective of acquiring in situ stiffness properties of the compacted soil layers. Recently, a new type of sensor, called compactometer, which in mounted on the drum of a roller and measures impact forces continuously with GPS, called as Continuous Compaction Control(CCC), has come into use in many countries such as America, Germany, Japan and so on. The main objective of this paper is to assess the potential use of these new devices as quality control and assurance devices for compacted soil layers. Based on this study, compactometer and the LFWD results werestrongly correlated with the result obtained from the PLT and the field density test.

Effect of Suspension Property on Granule Characteristics and Compaction Behavior of Fine Si3Na4 Powder (분산계 특성이 질화규소 미분의 과립특성 및 충진거동에 미치는 영향)

  • 이해원;오성록
    • Journal of the Korean Ceramic Society
    • /
    • v.32 no.4
    • /
    • pp.462-470
    • /
    • 1995
  • The characteristics of spray-dried granules are important for dry pressing operation since they have great influences on die-filling, compaction ratio, and resulting green microstructure. An attempt was made to control granule morphology and the packing structure of fine Si3N4 particles in granules by adjusting suspension property. Mercury porosimetry was used to characterize the pore structures of both granules and green compacts. Finally, the effects of particle packing structure in granules and green microstructure on sintering behavior were investigated.

  • PDF