• Journal of Computational Design and Engineering
• /
• v.2 no.4
• /
• pp.197-205
• /
• 2015

Bladed disk (BLISK) is a vital part in jet engines with a complicated shape which is exclusively machined on a five-axis machine and requires high accuracy of machining. Poor quality of tool orientation (e.g., false tool positioning and unsmooth tool orientation transition) during the five-axis machining may cause collision and machine vibration, which will debase the machining quality and in the worst case sabotage the BLISK. This paper presents a reference plane based algorithm to generate a set of smoothly aligned tool orientations along a tool path. The proposed method guarantees that no collision would occur anywhere along the tool path, and the overall smoothness is globally optimized. A preliminary simulation verification of the proposed algorithm is conducted on a BLISK model and the tool orientation generated is found to be stable, smooth, and well-formed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.10a
• /
• pp.24-29
• /
• 2002

In any rapid prototyping process, the layer by layer building process introduces an area error between the staircase and the surface line specified by the computer-aided design model. This affects the dimensional accuracy as well as the surface finish for different part build orientations. This paper describes a methodology for computing the area error for any orientation of the part built by the fused deposition modelling system. This technique can be applied to determine the best build orientation of the part, based on the minimum area error. This technique is verified by comparing the results with the experimental measurements of the area error of the parts built at different orientations.

• Composites Research
• /
• v.24 no.4
• /
• pp.41-47
• /
• 2011

This paper deals with anisotropic property and structural analysis for short fiber reinforced plastic composites manufactured by the injection molding process. The common approach for modeling this type of material is the consideration of the material as homogenous and isotropic. However, the common isotropy approach often results in unexpected failure. To overcome this, new structure analysis methodology was developed in order to consider fiber orientation effect using injection mold flow analysis and Halpin-Tsai equations for unidirectional composites and taking an orientation average. The numerical predictions are compared to experimental data for tensile specimen. The predicted mechanical properties agree well with experimental data for fiber orientation and weld line effect. The analysis system was also applied to an automobile part. The proposed anisotropic model predicted different mechanical properties by position of the part and different mechanical performance of the part was changed according to injection gate position.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.21 no.4
• /
• pp.699-709
• /
• 1997

The purpose of this study is to investigate consumer shopping orientation toward foreign brands in the context of clothing involvement, ethnocentrism, country-of-origin effects and demograpic variables. Prior to this paper, shopping orientation was studied in connection with ethnocentrism and country-of-origin effects. The questionnaire was distributed to 300 female consumers over twenty years old living in Pusan area and finally 213 data serfs were used for statistical analysis. By factor analysis, 6 clothing involvement factors were identified; fashion interest, symbolism, pleasure interest, inclination to harmony, aesthetic expression and perceived risk. A result of canonical correlation analysis about shopping orientation factors and clothing involvement factors is as follows. Two shopping orientation factors (follow to foreign brands and country-of-orion consciousness) positively correlate with three clothing involvement factors (fashion interest, symbolism and pleasure interest) , and two shopping orientation factors (preference to domestics and country-of-orion consciousness) positively correlate with author clohting involvement factor (percived risk). Anocova procedure revealed that five shopping orientation factors were related to clothing involvement factors, groups according to ethnocentric disposition, country-of-origin effects and demograpics respectively, even though there are some differences. Based on the conclusions, marketing strategies were developed.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.23 no.6
• /
• pp.566-576
• /
• 2003

Carbon-fiber reinforced plastics (CFRP) composite laminates often possess strong in-plane elastic anisotropy attributable to the fiber orientation and layup sequence. The layup orientation thus greatly influences its properties in a composite laminate. It could result in the part being rejected or discarded if the layup orientation of a ply is misaligned. A nondestructive technique would be very beneficial, which could be used to test the part after curing and to require less time than the optical test. In this paper, ultrasonic scanners were set out for different measurement modalities for acquiring ultrasonic signals as a function of in-plane azimuthal angle. The motorized scanner was built first for making transmission measurements using a pair of normal-incidence shear wave transducers. Another scanner was then built fer the acousto-ultrasonic configuration using contact transducers. A ply-by-ply vector decomposition model has been developed, simplified, and implemented for composite laminates fabricated from unidirectional plies. We have compared the test results with model data. It is found that strong agreement are shown between tests and the model developed in characterizing cured layups of the laminates.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2001.10a
• /
• pp.33-38
• /
• 2001

This study aims to systematically research the various phenomena which arise from compression molding of fiber reinforced plastic composites. Long fiber reinforced plastic composites are rib type compression molded in order to measure the orientation in products, and the specimens are photographed with soft X-ray. The intensity of the photograph is applied by an image scanner, and the fiber orientation distribution of products is measured by using an image processing technique.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.04a
• /
• pp.591-596
• /
• 2002

Fused deposition(FD) modeling by Stratasys Inc., is one of the material deposition subfamilies of solid freefrom fabrication(SFF) technologies. In this process, build material in the form of a flexible filament, is heated to a semi-liquid state and extruded from a controlled deposition head onto a fixtureless table in a temperature controlled environment. The position of nozzle is computer controlled relative to the base, which allows geometric complex models to be made to precise dimensions. FDM provide what the part was directly tested by the worker. It provide believable data. This Study is identify to surface roughness by build orientation adjustment. So, the paper is the study on surface roughness by build orientation at FDM.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.8
• /
• pp.983-991
• /
• 1988

In this paper, a new two dimensional processing method is presented, which determines the identity, position and orientation of a part. Matching between the object and model is performed in the frequency domain. The DFT of the object contour is decomposed to estimated the orientation of the object and to evaluate the similarity between the object and model. In this context, this new approach is very rbust with respect to noise and no preprocessing of the contour is required. Also, this method has many advantages over the conventional correlation technique. With only a few uniformly sampled points, this method can estimate the accurate orientation in an efficient manner even in a noisy environment.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.11
• /
• pp.42-50
• /
• 2001

In this paper, a new technique and theory are proposed which correct the orientation (inclination of a vertical axis) of a cylinder in vertical-micro positioning device. An algorithm for determining the orientation of the cylinder with a pair of displacement sensor units is derived and two types of the correction methods are described. To assess the performance and efficiency of the developed correction technique, the compensation errors originated from the correction algorithm and the machined characteristics of cylinder surface are evaluated from the geometrical considerations and the statistical techniques. Based upon the evaluation results, the maximum compensation error is estimated for the orientation of cylinder and the optimum correction technique is derived.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.8
• /
• pp.122-129
• /
• 1999

A 5-axis CNC machine tool is more useful compared with a 3-axis machine tool, because the position and the orientation of a tool tip can be controlled simultaneously. Unlike the 3-axis machine tool, the 5-axis machine tool has the volumetric position error and volumetric orientation error due to the quasi-static error of each machine tool joint which is a major source of machined part error. So, the generalized error synthesis model of the 5-axis CNC machine tool was developed to predict and to compensate for the volumetric position error and the volumetric orientation error. It was proposed that a compensation algorithm to correct simultaneously the volumetric position error and the volumetric orientation error of the 5-axis CNC machine by error inverse kinematic.