• Anatomy and Cell Biology
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• v.56 no.4
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• pp.482-493
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• 2023

Understanding the anatomy of suprascapular area helps the clinicians and surgeons in management of any disability at the shoulder region. This work aimed to clear the different morphological and morphometrical types of suprascapular notch (SSN). Unknown 120 dry human scapulae of both sides and 60 formalin-embalmed cadaveric upper limbs (40 males and 20 females) were used in the present study. Three main morphological forms of SSN were reported: J, U, and V-shaped. J-shaped notch showed the highest incidence followed by U-shaped then V-shaped one. Morphometrically, type (III) notch was the most prevalent in both dry bones and cadavers, while the incidence of type (II) was the lowest form. Also, the measurements of superior transverse diameter, middle transverse diameter and vertical dimension of the different types of the notch showed no side or sex significant difference. The suprascapular foramen with ossified superior transverse scapular ligament (STSL) was seen in 5.8% of dry bones and 10% of cadaveric specimens. Fan and band-shaped ossified transverse scapular ligaments were reported. Absence of SSN was seen in 10.8% of dry bones, 7.5% of male and 10% of female specimens with left side predominance. V-shaped, absence, and ossified STSL were considered as predisposing factors of suprascapular nerve entrapment syndrome. Knowledge of the morphology and morphometric parameters of SSN is of great clinical significance for anatomists, radiologists, physiotherapists, orthopedics and neurosurgeons to perform good diagnosis and best planning for surgical or arthroscopic interventions within the shoulder region.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.1
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• pp.89-95
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• 2016

This study investigated the design factors of the opening area in order to consider the kinematic stability of a valve plate, conducting an analysis of the reduction effects of pressure pulsation and flow ripple depending on the design factors, using the $SimulationX^{(R)}$ (Germany) hydraulic analysis program. Further, we performed a structure analysis to confirm the kinematic stability of the valve plate in a swash plate type piston pump, and analyzed the effects of pulsation on a 1-step V-type notch, 2-step V-type notch, and 2-step U-type notch to determine the effects of pulsation reduction. Finally, we show the effectiveness of our proposed design of the pre-compression sections on a valve plate in terms of low pulsation by using the hydraulic analysis program, $SimulationX^{(R)}$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1215-1216
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• 2013

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.2
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• pp.244-250
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• 2015

We propose a simulation technique to estimate the reduction effect of the pressure/flow pulsation by analysis of the pulsation variables and notch shape of the valve plate of a swash-plate-type variable piston pump. First, using SimulationX$^{(R)}$, we perform a theoretical kinematic analysis according to the variable swash-plate angle and rotational velocity in order to design a single-piston pump. In designing the notch shape of the valve plate of the swash-plate-type variable piston pump as one of the pulsation variables, we investigate the effect of the pulsation by comparing two notch types (circular type and V type). Then, we extend our analysis to a nine-piston pump model. This paper not only confirms the effect of the pressure/flow pulsation according to pulsation variables but can also be applied to the development of a SimulationX$^{(R)}$-based simulation technique for notch-shape optimization for a swash-plate-type variable piston pump.

• Journal of Mechanical Science and Technology
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• v.18 no.6
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• pp.1019-1025
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• 2004

Pressure variation is one of the major sources on noise emission in the axial type oil piston pumps. Therefore, it is necessary that the pressure variation characteristics of the oil hydraulic piston pumps be clarified to reduce the pump noise. Pressure variations in a cylinder at the discharge region and the pump noise were simultaneously measured with discharge pressures and rotational speeds during the pump working. To investigate the effects of the pre-compression and the V-notch in the valve plate, we used the three types of valve plates. In this research, it is clear that the pressure variation characteristics of axial type oil piston pumps is deeply related to the pre-compression and to the V-notch design in valve plate. Therefore, we could reduce the pump noise by using the appropriate pre-compression angle and the notch design that are between the suction port and the discharge port in valve plate.

• Journal of Electrical Engineering and Technology
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• v.9 no.5
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• pp.1577-1581
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• 2014

This paper presents a method to minimize torque ripple of a V-type IPMSM using the PSO (Particle Swarm Optimization) method with FEM. The proposed algorithm includes one objective function and three design variables for a notch on the surface of a rotor. The simulation model of the V-type IPMSM has 3-phases, 8-poles and 48 slots with 2 notches on the one-pole rotor surface. The arc-angle, length and width of the notch are optimized to minimize the torque ripple of the motor. The cogging torque of the model is reduced by 55.6% and the torque ripple is decreased by 15.5 %. Also, the efficiency of the motor is increased by 15.5 %.

• Computers and Concrete
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• v.33 no.3
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• pp.265-273
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• 2024

Predicting fracture properties requires an understanding of structural failure behaviour in relation to specimen type, dimension, and notch length. Facture properties are evaluated using various testing methods, wedge splitting test being one of them. The wedge splitting test was numerically modelled three dimensionally using the finite element method on self compacting concrete specimens with varied specimen and notch depths in the current work. The load - Crack mouth opening displacement curves and the angle of rotation with respect to notch opening till failure are used to assess the fracture properties. Furthermore, based on the simulation results, failure curve was built to forecast the fracture behaviour of self-compacting concrete. The fracture failure curve revealed that the failure was quasi-brittle in character, conforming to non-linear elastic properties for all specimen depth and notch depth combinations.

• Journal of Welding and Joining
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• v.13 no.1
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• pp.89-102
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• 1995

The evaluation of reheat cracking susceptibility in CrMoV turbine rotor steel was performed using thermally simulated heat affected zones. The examinations were carried out in terms of microstructural characterization, microhardness measurement and a Charpy type notch opening three point bend test. It was found that reheat cracking susceptibility increased as the peak temperature increased. This effect was due to the combined effects of the carbide dissolution and unrestricted grain growth at 1350.deg. C peak temperature. Reheat cracking susceptibility was estimated based on microhardness measurement and prior austenite grain size. It was established that for this particular material, reheat cracking in coarse grained heat affected zone can be eliminated if the microhardness is below about 360DPH and the grain size is below about 30.mu.m. It is evident that reheat cracking susceptibility can be eliminated or reduced by carefully controlling the welding parameters such that a refined structure is produced in the coarse grained heat affected zone.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1588-1596
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• 2022

In the nuclear power plants, stainless steel is widely used for fabrication of various components such as piping and pipe fittings. These piping components are subjected to cyclic loading due to start up and shut down of the nuclear power plants. The application of cyclic loading may lead to initiation of crack at stress raiser locations such as nozzle to piping connection, crown of piping bends etc. of the piping system. Crack initiation can also take place from the flaws which have gone unnoticed during manufacturing. Therefore, prediction of crack initiation life would help in decision making with respect to plant operational life. The primary objective of the present study is to compile various analytical models to predict the crack initiation life of the pipes with notch. Here notch simulates the stress raisers in the piping system. As a part of the study, Coffin-Manson equations have been benchmarked to predict the crack initiation life of pipe with notch. Analytical models proposed by Zheng et al. [1], Singh et al. [2], Yang Dong et al. [25], Masayuki et al. [33] and Liu et al. [3] were compiled to predict the crack initiation life of SA312 Type 304LN stainless steel pipe with notch under fatigue loading. Tensile and low cycle fatigue properties were evaluated for the same lot of SA312 Type 304LN stainless steel as that of pipe test. The predicted crack initiation lives by different models were compared with the experimental results of three pipes under different frequencies and loading conditions. It was observed that the predicted crack initiation life is in very good agreement with experimental results with maximum difference of ±10.0%.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.4
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• pp.104-112
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• 2018

Considering the shape of a valve plate in design is important for reducing the pulsation phenomenon, which is a negative factor in pump performance. The purpose of this study is to propose an optimized method for a valve-plate V-type notch of a piston pump by modeling and simulation. The method uses $SimulationX^{(R)}$, a commercial hydraulic analysis program, and to provide data for the designing of the notch. The opening areas are determined by performing kinematic analysis of the notch part where the opening area changes rapidly. After applying the result analysis, the main effects on maximum pressure pulsation and maximum backflow according to the notch design factors are analyzed by using the full factorial method of experimental design. The optimized solutions are derived for the notch design variables, based on the analyzed data.