Dong Hong Kim

A Study on Development of Automotive Panel of Bumper Reinforcement with High Strength Steel Using Roll Forming Process

Roll forming process is a sheet metal forming process where the forming occurs with rolls in several steps, often from an undeformed sheet to a product ready to use. And each pair of forming rolls installed in a forming machine operates a particular role in making up the required final cross-section. This process used to many industry manufactures and recently apply to automotive industry. This study, FEM simulation applied bumper reinforcement using SHAPE-RF software and analyzed about total effective strain, longitudinal strain, thickness according to the roll-pass.

Angle Calculation Rotation Angle of One-axis Manipulator in Laser Module

Laser assisted machining is the processing method that preheating brittle materials by laser heat source and cutting the soften area. This processing applied to various industries because it can be cutting difficult-to-cut materials. However, the laser assisted machining appeared the limitations of processing for equipped with the spindle. So, it assumed separate model that spindle and laser assisted machining. In feed, the calculation of changing the angle of the laser module according to preheat point and the shape of the feed is important and it tried easy calculating changing angle of 1-axis Manipulator in separate model. In 3 types feed shape, angle of 1-axis Manipulator was calculated when fixed and moved in the outside of spindle. In this study, suggest 2 types of methods for laser module when fixed and moved.

Study on Spring-Back Effect according to Roll Gap and Forming Velocity of Roll Forming Process

The spring-back and bow phenomenon in the roll forming process are important factors regarding the accuracy of evaluation of production goods. The purpose of this study was to determine the influence of spring-back and bow phenomenon according to the main variables (forming velocity and roll gap). The material of the forming sheet was high tension steel (SPFH 590), which has been used commonly in recent years. In order to accurately measure the spring-back and bow phenomenon, the forming sheet was formed into a V-shape. The study was applied to OFAT (One Factor at a Time) experimentation, with respect to the experimental variables (the forming speed and the roll gap). In the experimental results, the forming speed had a small influence on the spring-back and bow phenomenon. However, the roll gap had a greater influence on the spring-back and the bow phenomenon, as opposed to the forming speed.

Study on the Spring-Back Effect with Stress Distribution According to Forming Sheet Width in the Roll Forming Process

This study, based on finite element analysis, analyzed the spring back phenomenon and stress distribution of forming sheets (HTS) in the roll forming process. By comparison of the stress distribution, this study analyzed two kinds of simulation. The first simulation performed simple bending simulation before roll forming simulation. With reference to the first simulation results, the second simulation analyzed the relationship between the stress distribution and the phenomenon of spring back. We also studied the stress distribution effect for spring back in the forming sheet.

Study on Bending Process of Forming Analysis at the Edge of a Sphere and the Optimization of Initial Blank Shape

Material is deformed upon the application of an external force. If the external force is removed, the material either returns to the original shape, or it is transformed forever. The ability of a material transform without destroying it is called plasticity, and the permanent transformation is called plastic deformation. Using the plastic properties, of a material in processing is called plastic process. Press processing is a kind of the plastic processing method. In todays automotive industry and electronics industry, press processing is an indispensable processing method to produce frames or panels. In this study, the best initial shape before forming of blank metal material is determined for bending processes to produce a refrigerator door panel.

Die Design and Numerical Simulation for the Die Forging Forming of Shifting Fork

At present, the domestic most use the traditional machining methods of production, such as general milling, drill, ground, etc. But the traditional processing method is low material utilization ratio, time-consuming power consumption, and low production efficiency. as the same time the product quality is difficult to meet the requirement of high strength. In contrast, shifting fork forming die forging can improve labor productivity, and can obtain the ideal parts surface roughness and size accuracy. And with the forming of die forging the variable speed fork general rarely cutting processing, just in require special high points will has fine grinding. This design has completed the variable speed fork of die forging shape of mold design giving the design plan and design process. This topic is about the design of the numerical simulation, getting the expected of the press one.

The Development of Forming Analysis Technology for Material Selection Based on Different Manufacturing in REF SILL OTR-R/L Auto-Body Panel Stamping

Using a new method in this study, we were able to solve the problem with the existing method, which was panel manufacturing after selecting the most appropriate material from the possible manufacturing material. The possibility of application in the practical industry site and validity were verified. This study involves analyzing the stamping process problems by using AutoForm commercial software, which used the static-implicit method. According to this study, the results of the simulation will provide engineers good information to access the die design for optimization.

A Study on the Development of Tool Planning for REF SILL OTR-R/L Auto-Body Panel by Using Forming Analysis

The characteristics of the sheet metal process include the loss of material during the process, short processing time and excellent price and strength. The sheet metal process with the above characteristics is commonly used in the industrial field, but in order to analyze irregular field problems, a reliable and economical analysis method are needed. The finite element method is a very effective method to simulate the forming processes with a good prediction of the deformation behaviour. Among the finite element method, the static-implicit finite element method is applied effectively in order to analyze the real-size auto-body panel stamping processes, which include the forming stage.

Extrusion Foaming System for Fabricating Open-Cell Structure of Low Density Polyethylene (LDPE)

Low Density Polyethylene (LDPE) foam of open-cell type was manufactured through extrusion foaming system using a physical blowing agent for the application of sound absorption. For the purpose of enhancing the open cell content, salt powder was blended with LDPE changing the content and particle size. Scanning electron microscopy (SEM) analysis was carried out in order to observe the cell morphology. With a view to characterizing the open-cell structure, open-cell content and expansion ratio were measured with extruded foams. Finally the effect of formulation and processing parameters on cell morphology was investigated.

A Study on Developing Robustness Engineering by Using Stochastic Analysis Method

The purpose of this study is to evaluate the influence of the scatter in mechanical properties and stamping process parameters on an industrial sheet metal forming process. Based on a previously optimized forming process, a robustness analysis has been performed. The robustness analysis clearly showed production problems for the part not initially revealed by the analysis of the process that was trimmed for “optimality”. The sensitivity of the results on the variation of the parameters was evaluated. It was shown that all parts of the sheet do not react equally sensitively to the variation of the input. Zones of critical response could be identified in accordance with the zones on the actual part that showed failure in mass production. The results reveal that the common practice of performing evaluations with fixed safety margins is non-effective and hence very dangerous, or is extremely conservative and thus costly. The application of stochastic simulation methods reduces the need for wide safety margins while simultaneously increasing the reliability of the process by incorporating uncertainty into the simulation