• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.437-446
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• 2013

There have been numerous studies on end milling processes. However, these have been restricted to the application of tools for special cutting purposes. A side milling cutter can handle long, deep, and open slots in a more efficient manner, and it provides the best stability and productivity for this type of milling. In this paper, a method to predict the cutting forces in side milling is described, and simulated cutting forces are compared with those obtained by cutting experiments. In particular, the side milling process easily generates relative motion between the tools and the workpiece because it produces intermittent cutting forces that cause vibrations over a wide frequency range. Therefore, the application of a dynamic cutting model instead of a static cutting model is appropriate to forecast the cutting forces more accurately.

• Journal of Mechanical Science and Technology
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• v.15 no.7
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• pp.982-994
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• 2001

Commercially available software packages permit to position human models of various geometries in practical scenarios while respecting the anatomical constraints of the skeletal joints and of the bulk of the bodies. Beyond such features, the PAM-Comfort(sup)TM software has been conceived to provide direct access to the muscular forces needed by humans to perform physical actions where muscle force is required. The PAM-Comfort(sup)TM human models are made of multi-body linked anatomical skeletons, equipped with finite elements of the relevant skeletal muscles. The hyper-static problem of determination of muscle forces is solved by optimisation technique. Voluntary stiffening of muscles can be added to the basic contraction levels needed to perform a specific task. The calculated muscle forces obey Hills model. The model and software have been applied in several interesting scenarios of various fields of application, such as car industry, handling of equipment and sports activities.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.04a
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• pp.101-108
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• 1993

A simplified dynamic analysis method for high-rise building structures is proposed in this study. In the proposed method, member forces are obtained through static analysis using story forces derived from story shear forces which are obtained using dynamic analysis procedure. Major advantage of the proposed method is in the convenience in load combinations for design analysis.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.123-133
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• 1998

The effectiveness of TiN ion-plating was examined with TiN ion-plated Co-Cr wires(.016“, .016”x.022“) on three different types of bracket(TiN ion-plated metal bracket ceramic bracket and plastic bracket). Maximum static frictional forces and characteristic curves obtained from the frictional characteristic graph, were compared and surface roughness of wires and bracket slots before and after friction experiment was observed by SEM. The obtained results were as follows $\cdot$The frictional forces of TiN ion-plated wires were significantly lower than those of non ion-plated wires(p<0.05). $\cdot$On the effect of wire shape, the frictional forces of round wires were significantly lower than those of rectangular wires(p<0.05) $\cdot$As the result of the SEM observation on the wires and bracket slots after the friction experiment the surface of non ion-plated wires was rougher than that of TiN ion-plated ones. $\cdot$The difference between the static frictional forces and the kinetic frictional forces was not significant in case of the TiN ion-plated round ins, but the static frictional forces were a little higher than the kinetic frictional forces in the TiN ion-plated rectangular wires. $\cdot$The static frictional forces were much higher than the kinetic frictional forces in the case of non ion-plated wires.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.473-478
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• 2003

This paper presents static and dynamic measurement of the stress and motion characteristics for crawler type excavators. Eight scenarios were prepared for static measurement based on two extreme digging positions, maximum digging reach position and maximum digging force position. The measured items for static motion included stress, cylinder pressure, cylinder stroke and digging force. The measured static stresses showed that asymmetric digging force acting on a bucket induced higher stress level than symmetric one. The measured static pressures and digging forces also agreed with design pressures and design digging forces, respectively. The dynamic measurement was performed for two types of motion, that is, simple reciprocation of each cylinder and actual digging motion. The measured items for dynamic motion were stroke and pressure of each cylinder, stresses on the working device and acceleration on the upper plate of an arm. The measured data showed that the natural frequency of the excavator highly depended on the hydraulic stiffness of cylinders. Digging motion tests revealed that digging motion was closer to static motion rather than dynamic one.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1003-1008
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• 2007

Compliance effect consideration method for real-time multibody vehicle dynamics is proposed using quasi-static analysis. The multibody vehicle model without bush elements is used based on the subsystem synthesis method which provides real-time computation on the multibody vehicle model. Reaction forces are computed in the suspension subsystem. According to deformation from the quasi-static analysis using reaction forces and bush stiffness, suspension hardpoint locations and suspension linkage orientation are changed. To validate the proposed method, quarter car simulations of McPherson strut and multilink suspension subsystems. Full car bump run simulations are also carried out comparing with the ADAMS vehicle model with bush elements. CPU times are also measured to see the real-time capabilities of the proposed method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.2
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• pp.162-169
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• 2008

Compliance effect consideration method for real-time multibody vehicle dynamics is proposed using quasi-static analysis. The multibody vehicle model without bush elements is used based on the subsystem synthesis method which provides real-time computation on the multibody vehicle model. Reaction forces are computed in the suspension subsystem. According to deformation from the quasi-static analysis using reaction forces and bush stiffness, suspension hardpoint locations and suspension linkage orientation are changed. To validate the proposed method, quarter car simulations of McPherson strut and multilink suspension subsystems are performed. Full car bump run simulations and fish hook handling test simulations are also carried out comparing with the ADAMS vehicle model with bush elements. CPU times are also measured to see the real-time capabilities of the proposed method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.315-319
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• 2004

Static and dynamic responses of micro cantilever beam structures undertaking electrostatic forces are obtained employing Galerkin's method based on Euler beam theory. Variations of static and dynamic responses as well as resonant frequencies are estimated for several sets of beam properties and applied voltages. It is shown that the applied voltage influences the deflection and the modal characteristics significantly. Such information can be usefully employed for the design of MEMS structures.

• Journal of Korean Association for Spatial Structures
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• v.17 no.1
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• pp.77-84
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• 2017

Vortex-induced vibration and instability vibration of tall buildings are very important fluid-structure interaction phenomenon, and many fundamental questions concerning the influence of body movement on the unsteady aerodynamic force remain unanswered. For tall buildings, there are two experimental methods to investigate the characteristics of unsteady aerodynamic forces, one is forced vibration method and the other is free vibration method. In the present paper, a free vibration method was used to investigate the unsteady aerodynamic force on tall building whose aspect ratio is 9 under boundary layer simulating city area. Wind pressures on surfaces and tip displacements were measured simultaneously, and the characteristics of tip displacements and generalized forces were discussed. It was found that variation of across-wind displacements showed different trend between the case when wind speed increases and wind speed decreases, and the fluctuating generalize forces in across-wind direction of vibrating model are larger than that of static model near the resonant wind speed and approach to the static value. And for higher wind speed range, there were two peaks in across-wind power spectra of generalize forces of vibrating model, which means that two frequency components are predominant in unsteady aerodynamic forces.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.642-651
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• 2009

The history of excavator design is not long enough which still causes most of the design considerations to be focused on static analysis or simple functional improvement based on static analysis. However, the real forces experiencing on each component of excavator are highly transient and impulsive. Therefore, the prediction and the evaluation of the movement of the excavator by dynamic load in the early design stage through the dynamic transient analysis of the excavator and ensuring of design technique plays an importance role to reduce development-cost, shorten product-deliver, decrease vehicle-weight and optimize the system design. In this paper, Commercial software DADS and ANSYS help to develop the track model of the crawler type excavator, and to evaluate the performance and the dynamic characteristics of excavator with various simulations. For that reason, the track of crawler type excavator is modelled with DADS Track Vehicle Superelement, and the reaction forces on the track rollers were predicted through the driving simulation. Also, the upper frame and cabin vibration characteristics, at the low RPM idle state, were evaluated with engine rigid body modelling. And flexibility body effects were considered to determine the more accurate joint reaction forces and accelerations under the upper frame swing motion.