• Proceedings of the KSME Conference
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• 2000.11a
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• pp.304-309
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• 2000

Strain gage method is used to evaluate the mode I dynamic stress intensity factor of marging steel(18Ni) and titanium alloy(Ti-6A1-4V). To decide the best strain gage position on specimen, static fracture toughness test was performed. Then instrumented charpy impact test and dynamic tensile test was performed by using strain gage method for evlauating dynamic stress intensity factor. Strain gage signals on the crack tip region are used to calculate the stress intensity factors. It is found that strain gage method is more useful than method by using load which is obtained from impact tup to assess dynamic characteristics such as dynamic stress intensity factor.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.271-272
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• 2008

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.12
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• pp.987-993
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• 2001

In this paper, we presents the construction details and output characteristics of a thick film piezoresistive strain gage. The thick film was printed on the ceramic diaphragm back side by screen printing and cured at 850$^{\circ}C$. The strain distribution and deflection on ceramic diaphragm were performed with finite-element method(FEM tool ANSYS-5.3). Various thick film strain gage characteristics were analysed, including nonlinearity, hysteresis, stability and sensitivity of thick film strain gages.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.12
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• pp.1019-1025
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• 2003

We introduce a new auto-calibration/simulation method for a strain gage type transducer/signal-conditioner which guarantees the output linearity and compensates the error automatically. We design a micro voltage supply which is able to interface either AC or DC type excitation voltage. A new strain gage simulator is also designed. We make linearity output of the signal conditioner and can compensate error automatically with this new auto calibration/simulation method. The experimental results show that the error between the real value and the expected one is less than 1%.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1430-1433
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• 2003

Transducers, which are incorporated in control devices for fixed wing aircraft, land vehicles. and weapon systems were designed and manufactured by use of semiconductor strain gages. These transducers consist of three parts; flange mounts, sensing rods, and semiconductor strain gages. In this investigation, we designed cylindrical sensing rods with high sensitivity and developed installation procedures of semiconductor strain gages. The semiconductor strain gage has hish gage factor such that it can produce high resistance change in spite of low strain, but it is so small and fragile that one should handle carefully and sophisticated installation method is needed for good performances. The prototype transducers are manufactured, and then tested about three important factors: sensitivity, linearity, and hysteresis. We got results or 0.084 V/N sensitivity, 0.2% nonlinearity, and 0.5% hysteresis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.4
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• pp.343-351
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• 2004

The flaw assessment method based on ${delta}_5$ parameter was recently proposed and put to the practical use. However: since it is almost impossible to measure the ${delta}_5$ by the existing commercial clip gager, we need to develope the specially designed gages which are suitable for that purpose. In this research, a double cantilever type ${delta}_5$ clip gage with the traveling distance of 4mm was developed by the finite element analysis and the construction of Wheatstone bridge circuit including strain gages. The linearity of developed ${delta}_5$ clip gage was evaluated by the MTS extensometer calibrator with the proper adapters which allow the 6s clip gage to sit on the calibrator. Consequently, the 6s clip gage revealed the good linearity between the output voltage and the traveling distance of gage.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.1
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• pp.53-64
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• 2000

Strain gage method is investigated to evaluate the mode I stress intensity factor. Two types of specimens for CT and three point bend specimen are used. Sharp notch of specimens is manufactured by wiring discharge machining. Strain gages signal from the crack tip region are used to calculate stress intensity factors. The results are compared with those of the ASTM E399 method and finite element analysis. The present experimental results coincide well with the data obtained from finite element analysis. Attached position of strain gage should be seriously considered during the application of this method.

• Journal of the Korean Society of Safety
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• v.17 no.3
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• pp.13-21
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• 2002

The tincture toughness is evaluated by using U(compact tension) and 3PB(three point bending) specimens of AI alloys far propulsive engine. To evaluate the static fracture toughness, strain gage method is used. The static fracture toughness obtained from the strain measurement is compared with the results by ASTM standard and FEM analysis. For the reliable evaluation of fracture toughness, strain gages are attached at various positions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.112-115
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• 2005

The objectives of this study are to evaluate the dynamic fracture toughness of advance glass ceramics(MACOR glass-filled ceramic, Corning Glass Works) for dome port cover of the ramjet. Static and dynamic fracture toughness tests are performed using strain gage method in the variation of notch radii.

• Journal of Korean Society of Steel Construction
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• v.18 no.5
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• pp.625-631
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• 2006

Residual stresses in structural materials are stresses that exist in the objective without the application of any service or other external loads. Manufacturing processes are the most common causes of residual stress. To examine the effect and the distribution of residual stress due to press forming and welding in the production of a 600MPa-class steel tube, a residual stress evaluation test was performed. The measurement used the Hole-Drilling Strain Gauge Method and evaluated the distribution of residual stress, which measured a total of 59 places near the welding line.