• Title/Summary/Keyword: Load evaluation

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Experimental Method for Durability Evaluation of a Chisel Mounted on a Composite Working Implement

  • Han, Jeongwoo;Moon, Sanggon;Lee, Geunho;Kang, Daesik
    • Journal of Biosystems Engineering
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    • v.42 no.4
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    • pp.251-257
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    • 2017
  • Purpose: A chisel mounted on working implement, such as agricultural machinery used in irregular farming conditions, is subjected to highly variable fatigue loading during work. To ensure the safety of the chisel on a working implement for the duration of its service life, fatigue testing must be performed with the proper fatigue test load conditions. In this study, working loads for a chisel were developed by reconstructing loads from strain gage data collected during field tests and used to conduct fatigue tests on the chisel component. Methods: FE analysis with nCode software was utilized to select the proper quantity and locations of strain gages for load measurements. A fatigue test was performed to experimentally verify the fatigue strength of the chisel and to evaluate the validity of the load history developed with the load reconstruction technique. Results: A strain history for the chisel was obtained from data collected during field tests. The data was filtered for the 14-16 km/h speed range, connected, and merged. The chisel load history was developed using the load reconstruction technique. The resulting load history was expressed as a load spectrum using the rain-flow counting method. Conclusions: A fatigue test was conducted on a chisel under a constant load condition with an equivalent load amplitude and number of cycles, as calculated by Miner's Rule for linear damage accumulation. During the fatigue test, there were no cracks at any position. It is concluded that the fatigue test method proposed in this study can be utilized successfully as a durability evaluation method for the chisel.

Thermal Performance Evaluation of Design Parameters and Development of Load Prediction Equations of Office Buildings (사무소 건설의 설계변수 열성능 평가 및 부하예측방정식 개발)

  • 석호태;김광우
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.9
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    • pp.914-921
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    • 2001
  • The objective of this study is to evaluate the design parameters and to develop the cooling and heating load prediction equations of office buildings. The building load calculation simulation was carried out using the DOE-2.1E program. The results of the simulation was used as a data for ANOVA and multiple regression analysis which could develop the load prediction equations.

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Quantitative Evaluation of Median Nerve Motor Function in Carpal Tunnel Syndrome Using Load Cell : Correlation with Clinical, Electrodiagnostic, and Ultrasonographic Findings

  • Kim, Dong Hwan;Park, Sung Bae;Lee, Sang Hyung;Son, Young-Je;Chung, Gih Sung;Yang, Hee-Jin
    • Journal of Korean Neurosurgical Society
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    • v.54 no.3
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    • pp.232-235
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    • 2013
  • Objective : Major complaints of carpal tunnel syndrome (CTS) are sensory components. However, motor deficit also impedes functional status of hand. Contrary to evaluation of sensory function, the objective, quantitative evaluation of median nerve motor function is not easy. The motor function of median was evaluated quantitatively using load cell and its correlation with findings of electrodiagnostic study (EDS) was evaluated. Methods : Objective motor function of median nerve was evaluated by load cell and personal computer-based measurement system. All of the measurement was done in patients diagnosed as having idiopathic CTS by clinical features and EDS findings. The strength of thumb abduction and index finger flexion was measured in each hand three times, and the average value was used to calculate thumb index ratio (TIR). The correlation of TIR with clinical, EDS, and ultrasonographic findings were evaluated. Results : The TIR was evaluated in 67 patients (119 hands). There were 14 males and 53 females, mean age were 57.6 years (range 28 to 81). The higher preoperative nerve conductive studies grade of the patients, the lower TIR was observed [p<0.001, analysis of variance (ANOVA)]. TIR of cases with thenar atrophy were significantly lower than those without (p<0.001, t-test). TIR were significantly lower in patients with severe median nerve swelling in ultrasonography (p=0.042, ANOVA). Conclusion : Measurements of median nerve motor function using load cell is a valuable evaluation tool in CTS. It might be helpful in detecting subclinical motor dysfunction before muscle atrophy develops.

Constructing Database and Probabilistic Analysis for Ultimate Bearing Capacity of Aggregate Pier (쇄석다짐말뚝의 극한지지력 데이터베이스 구축 및 통계학적 분석)

  • Park, Joon-Mo;Kim, Bum-Joo;Jang, Yeon-Soo
    • Journal of the Korean Geotechnical Society
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    • v.30 no.8
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    • pp.25-37
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    • 2014
  • In load and resistance factor design (LRFD) method, resistance factors are typically calibrated using resistance bias factors obtained from either only the data within ${\pm}2{\sigma}$ or the data except the tail values of an assumed probability distribution to increase the reliability of the database. However, the data selection approach has a shortcoming that any low-quality data inadvertently included in the database may not be removed. In this study, a data quality evaluation method, developed based on the quality of static load test results, the engineering characteristics of in-situ soil, and the dimension of aggregate piers, is proposed for use in constructing database. For the evaluation of the method, a total 65 static load test results collected from various literatures, including static load test reports, were analyzed. Depending on the quality of the database, the comparison between bias factors, coefficients of variation, and resistance factors showed that uncertainty in estimating bias factors can be reduced by using the proposed data quality evaluation method when constructing database.

Light weight vehicle design by stick model (스틱모델에 의한 차체 경량화 설계)

  • 김천욱;김지홍
    • Journal of the korean Society of Automotive Engineers
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    • v.12 no.5
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    • pp.97-106
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    • 1990
  • A method of weight evaluation of the load-bearing structural elements of cars is presented and the weight ratio of the analysis model is investigated. Replacing the materials of floor elements of the car into the high-strength steel, a considerable weight-reduction of the model has been obtained. The 1500cc model is selected for the present study and the stick model analysis is employed for the structural analysis. The torsional stiffness of the weight-reduced model is also evaluated and it is shown it has a reasonable rigidity. The ratio of the weight of the load-bearing structural elements to the unladen vehicle weight of cars is about 0.12for the 1500cc model and the weight-reduction of this study can be obtained around 17% of the weight of the load-bearing structural elements.

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Evaluation of Load Carrying Capacity of RC Slab Bridges Considering Moment Redistribution (모멘트 재분배를 고려한 RC 슬래브교의 내하력 평가)

  • Kim Hu Seung;Kim Dae Joong;Yum Hwan Seok;Kim Woo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.335-338
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    • 2005
  • This paper describes a proposal for evaluation load carrying capacity of reinforced concrete slab bridges considering the moment redistribution. Recognition of redistribution of moments can be important because it permits a more realistic appraisal of the actual load-carrying capacity of a structure, thus leading to improved economy. In addition, it permits the designer to modify, within limits, the moment diagrams for which members are to be designed. The predicted results shows that moment redistribution are different from estimated by the current KCI, ACI 318-02, EC2 provisions, and propose reasonable load carrying capacity of the reinforced concrete slab bridge.

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Evaluation of Wheel Load Fatigue Performance of FRP-Concrete Composite Deck (FRP-콘크리트 합성 바닥판의 윤하중 피로 성능 평가)

  • Cho, Keun-Hee;Park, Sung-Yong;Cho, Jeong-Rae;Kim, Sung-Tae;Kim, Byung-Suk
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.38-41
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    • 2006
  • Wheel load fatigue experiment is carried out on a FRP-concrete composite deck. In FRP-concrete composite deck, FRP plays a role of a main tensile member as well as a permanent formwork and concrete plays a role of a main compressive member. Wheel load fatigue experiment, which shows more realistic behavior than pulsating fatigue experiment, is selected as a fatigue performance evaluation method. Until 1,000,000 cycles of loadings, load resistant performance is maintained without any loss, while residual deflection is increased.

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Strength Evaluation of Bogie by Loading Test (하중시험에 의한 대차의 강도 평가)

  • Yoon Sung-Cheol;Kwon Sung-Tae;Kim Myung-Rong;Lee Kang-Won
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.622-627
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    • 2004
  • This paper describes the result of load test of bogie frame. The purpose of test is to evaluate an safety which bogie frame shall be considered fully sufficient rigidity so as to satisfy proper system function under maximum load. Bogie system consist of bogie frame, suspensions, wheel-sets, brake system and transmission system. Among these component, the bogie frame is the most significant component subjected to the vehicle and passenger loads. The evaluation method is used the JIS E 4207 specification throughout the static load test. The test results have been very safety and stable for design load conditions.

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A safety evaluation on the loading and vibration test of freight car (화차 안전성 평가를 위한 차체 정하중시험 및 진동시험)

  • 권성태;정종덕;김원경;홍용기;허현무
    • Proceedings of the KSR Conference
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    • 2002.10a
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    • pp.92-97
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    • 2002
  • This paper describes the result of carbody and vibration test for freight car. The purpose of the test is to evaluate an safety which carbody structure shall be considered fully sufficient rigidity so as to load a freight car under maximum load and operating condition on line track. The test carbody is constructed by RS korea co., LTD. in accordance with KNR specification. The test cases of the carbody is tested the vertical load and compressive load to verify the strength and stiffness. The vibration test is tested for analysis and evaluation of vibration, to allow for the fact that mechanical vibration in railway vehicles have specific characteristics.

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