• International Journal of Aeronautical and Space Sciences
• /
• 제14권4호
• /
• pp.350-355
• /
• 2013

Electrical resistance change measurements were performed, to detect fatigue damage of a quasi-isotropic CFRP and cross-ply CFRP laminates. A four-probe method was used to measure the exact electrical resistance change. A three-probe method was used to measure the electrical contact resistance change, during long cyclic loading. The specimen side surface was observed using a video-microscope to detect damage. The measured electrical resistance changes were compared with the observed damage. The results of this study show that the electrical resistance increase of the quasi-isotropic laminate was caused by a delamination crack between ${\pm}45^{\circ}$ plies. Matrix cracking caused a small electrical resistance increase of the cross-ply laminate, but the decreased electrical resistance caused by the shear-plastic deformation impedes matrix-cracking detection.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.2480-2484
• /
• 2005

Electrical resistance tomograpy (ERT) maps resistivity values of the soil subsurface and characterizes buried objects. The characterization includes location, size, and resistivity of buried objects. In this paper, truncated least squares (TLS) is presented for the solution of the ERT image reconstruction. Results of numerical experiments in ERT solved by the TLS approach is presented and compared to that obtained by the Gauss-Newton method.

• 전기학회논문지P
• /
• 제58권4호
• /
• pp.597-601
• /
• 2009

Green car such as a hybrid electrical vehicle and fuel cell vehicle is developed as a commercial target. UN/ECE/WP29 is developing GTR of HFCV and establishing the regulation and standard of electrical safety by ELSA. The regulation and standard about Electrical safety of vehicle are prescribed in ISO, UN/ECE, FMVSS, Japanese Attachment and so on, in case of insulation resistance is referred to keep more than 100/Vdc, 500/Vac. However, accurate method to measure insulation resistance agreeable to structure of vehicle does not exist now, it is actually that correctness of measurement drops according to the feature of battery and fuel cell stack. In this paper, the method to measure insulation resistance for protection against electrical shock by direct contact or indirect contact in Green Car will be indicated by making a comparison between the insulation measurement in standard of electrical safety and the experiment results for HEV and HFCV.

• 조명전기설비학회논문지
• /
• 제19권3호
• /
• pp.119-126
• /
• 2005

Electrical resistance tomography(ERT)는 적절하게 설계된 전류를 대지 지하에 주입하여 이에 따른 인가전압을 대지 경계에서 측정한 후 이를 근거로 ERT의 영상복원 알고리즘에서 대지 지하의 대지저항률 분포를 얻고 대지 지하에 뭍힌 물체를 크기와 위치, 그리고 저항률에 대한 특성을 파악할 수 있는 기술이다. 본 논문에서는 ERT의 영상복원 기법으로 Gauss-Newton, TLS와 SIRT 방법들을 살펴본다. 컴퓨터 시뮬레이션을 통해 TLS 방법을 이용한 ERT 영상복원의 성능이 Gauss-Newton와 SIRT방법에 의해 얻어진 결과보다 향상되는 것을 보이도록 한다.

• Journal of international Conference on Electrical Machines and Systems
• /
• 제2권3호
• /
• pp.288-294
• /
• 2013

This paper introduces a novel method of on-line identifying the stator resistance and leakage inductance of dual three phase induction motor (DTPIM). According to the machine mathematical model, the stator resistance and leakage inductance can be estimated using the voltage and current values in harmonic subspace. Thus a method of voltage vector injection in harmonic subspace (VVIHS) is proposed, which causes currents in harmonic space. Then the errors between command and actual harmonic currents are utilized to regulate the machine parameters, including stator resistance and leakage inductance. The principle is presented and analyzed in detail. Experimental results prove the feasibility and validity of proposed method.

• 에너지공학
• /
• 제20권1호
• /
• pp.21-25
• /
• 2011

본 연구에서는 방사성 폐기물을 처리하는 원통형 회전 분리기를 감시하기 위해 전기 저항법을 제안하고 수학적 모델을 연구하였다. 회전형 방사성 폐기물 분리기에서 관 벽에 설치된 한 쌍의 전극의 전기 저항은 표면을 따라 형성된 불용해성 입자의 환상 영역의 두께와 그 영역의 불용해성 입자의 농도와 관련이 있다. 본 연구는 전위 방정식에 대한 2차원 해와 실험적인 전도도-농도 관계를 기반으로 전술한 인자들 사이의 해석적 관계를 기술하였다. 또한, 원통형 회전 분리기를 감시하기 위한 전기 저항법의 적용 가능성을 논의 하였다.

• International Journal of Safety
• /
• 제7권2호
• /
• pp.1-6
• /
• 2008

In this paper, the effects of the position and the angle of the potential probes on the measurements of the ground resistance using the fall-of-potential method are described and the testing techniques for minimizing the measuring errors are proposed. The fall-of-potential method is theoretically based on the potential and current measuring principle and the measuring error is primarily caused by the position and angle of auxiliary probes. In order to analyze the relative error in the measured value of the ground resistance due to the position of the potential probe, the ground resistance was measured for the case in which the distance of the current probe was fixed at 50[m] and the distance of the potential probe was located from 10[m] to 50[m]. Also, the potential probe was located in turn at $30[^{\circ}]$, $45[^{\circ}]$, $60[^{\circ}]$, $90[^{\circ}]$, and $180[^{\circ}]$. As a consequence, relative error decreased with increasing distance of the potential probe and decreasing angle between the current probe and potential probe. The results could help to determine the position of the potential probe during the ground resistance measurement.

• Geomechanics and Engineering
• /
• 제39권1호
• /
• pp.105-113
• /
• 2024

Recently, electrical resistivity surveys have been used to obtain information related to underground structures including burial structure type and depth. However, various field conditions hinder understanding measured electrical resistance, and thus there is a need to understand how various geometries affect electrical resistance. This study explores the effect of geometric parameters of a structure and electrodes on electrical resistance in the framework of the finite element method. First, an electrical resistance module is developed using the generalized mesh modeling technique, and the accuracy of the module is verified by comparing the results with the analytical solution for a cylindrical electrode with conical tip. Then, 387 cases of numerical analysis including geometric parameters of a buried structure and electrodes are conducted to quantitatively estimate the detection depth under a steady-state current condition. The results show that electrical resistance is increased as (1) shallower burial depth of structure, (2) closer distance between ground electrode and structure, (3) longer horizontal electrode distance. In addition, the maximum detection depth corresponding to converged electrical resistance is deeper as (4) closer distance between ground electrode and structure, (5) shorter horizontal electrode distance. The distribution of the electric potential around the electrodes and underground structure is analyzed to provide a better understanding of the measured electrical resistance. As engineering purpose, the empirical equation is proposed to calculate maximum detection depth as first approximation.

• 정보저장시스템학회논문집
• /
• 제3권4호
• /
• pp.160-166
• /
• 2007

In this paper, the measured electrical resistance method is proposed to analyze the ramp-tab contact during the load/unload (L/UL) process. Since this method supplies the voltage change due to the resistance change, we can easily and conveniently identify the ramp-tab contact from the acoustic emission (AE) signal. At first, we carefully deposit the conductive material on the surface of the conventional ramp by sputtering method. The ratio frequency (RF) magnetron co-sputtering system is applied to accomplish the deposited double-layers on the ramp surface. One layer is the stainless steel for the conductive layer and the other is the titanium layer for the cohesive function between the ramp surface and the stainless steel layer. In order to guarantee the stiffness and damping properties of the original ramp, the deposited conductive layer is intended to have very thin thickness. After integration the proposed ramp device into the L/UL system and networking the electrical resistance circuit, the L/UL performance is experimentally evaluated by comparing the measured electrical resistance signal and AE signal.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
• /
• pp.146-147
• /
• 2007

A universal four-point contact measurement method, has an advantage of non-existence of contact resistance, is demonstrated by the experiments with carbon nanotubes and ZnO nanowire. Ti/Au and Pt are tried to compare the influence of contact resistance between two different metals. These metals are selected to make Ohmic contact and Schottky contact originated from their different work functions. For precise experiments, Ti/Au and Pt are separately evaporated to form double 'four-point contact electrodes' on CNTs or ZnO, and the voltage-current characteristics are measured. This method can be applied to universal resistivity measurement for nanotubes and nanowires.