In Pyo Cha

A Study on the Nondestructive Evaluation of Carbon/Carbon Brake Disks Using Infrared Thermography

Carbon/carbon brake disks that use carbon fibers impregnated in a carbon matrix are widely utilized in aircrafts and automobiles owing to their high strength, high heat conductivity, low density, and excellent overall mechanical properties. Carbon/carbon brake disks are high cost products and require multi-process manufacturing. The safety and material efficiency of defective products reduces significantly and nondestructive testing is required to monitor the quality, homogeneity, and integrity of the material. In general, radiographic evaluations pose safety problems owing to the use of radiation in such evaluations and ultrasonic flaw detection is difficult to use because of its dependence on the surface of the specimen. This study uses an infrared thermography camera technique, which is not influenced by the sample surface, to monitor the heterogeneity of materials during the manufacturing process and to thus prove the reliability of the method.

A Study on the Structure Analysis of Skate for Transportation Using Composite Materials

As society became more complex, the logistics also increased, demanding for logistics transport vehicles and feeder has increased. Because the self-weight of skate for cargo transport used in this study is heavy, it needs to be weight lightening. However there is a lack of capital and technology not to improve lasting. We conducted FEM studies about weight lightening applying composites on cargo transport skate and the stiffness can be obtained at the same time. However, due to the presence of discontinuities such as holes in the parts. If you are applying composite, Because this causes the degradation of the strength of the material under static and fatigue load induced stress concentration in parts. In order to examine the safety of the cargo transport skate, you must consider the impact of the static strength damage on the stress concentration because of the discontinuous parts. In this study, therefore, the cargo skate was performed to evaluate the structural analysis through the FEM analysis. As a result, it was found that CFRP compared to existing SM45C is superior 25% when considering the characteristics. It indicated the best results in about 30% of the weight lightening.

Structural Analysis and Optimal Design of Lightweight Skate for Loading and Unloading

Topology optimization and shape optimization of structural optimization techniques are applied to transport skate the lightweight. Skate properties by varying the design variables and minimize the maximum stress and strain in the normal operation, while reducing the volume of the objective function of optimal design and Skate the static strength of the constraints that should not degrade compared to the performance of the initial model. The skates were used in this study consists of the main frame, sub frame, roll, pin main frame only structural analysis and optimal design was performed using the finite element method. Simplified initial model set design area and it compared to SM45C, AA7075, CFRP, GFRP was using the topology optimization. Strength does not degrade compared to the initial model, decreased volume while minimizing the stress and strain results, the optimum design was achieved efficient lightweight.