Papers by Keyword: Contact Width

Abstract: Previous studies on corrugated metal gaskets have established that the contact width, contact stress, and surface roughness are important design parameters for optimizing gasket performance. However, the contact stress and contact width considering the surface roughness when the leakage occur did not defined yet. In this study, we determined the real contact stress and contact width when leakage started on 25A-size metal gasket. The contact width determined through a comparison between simulation and experimental results. The contact stress determined through a simulation analysis. The experiment involves a helium leakage test using new metal gaskets having different surface roughness levels. The result justified that the real contact width and average contact stress when the leakage started occur were 0.195mm and 800MPa, respectively. There is a good agreement for contact width both by simulation and experiment result. The contact width for flange having surface roughness 1.5μm is longest than the others.

Abstract: Contact width is important design parameter for optimizing design of new metal gasket. The contact width was found have relationship with helium leak quantity. Increasing axial force, the contact width will increase and helium leakage will decrease. This study we conducted the surface roughness evaluation of 25A-size metal gasket before and after use. The results denote the real contact width after contact with flange having different surface roughness. The real contact width for the flange having smoother surface roughness is wider than the rougher one.

Abstract: Previous studies on corrugated metal gaskets have established that the contact width, contact stress, and surface roughness are important design parameters for optimizing gasket performance. However, the metal gaskets studied previously required a high axial force for the tightening process; in addition that metal gaskets tend to corrode easily. In this study, we examined the deformation mode of a thin stainless gasket using a finite element method (FEM) analysis. A final evaluation was made using a compression examination. The analysis based on the dimension of flat and convex portion. The load, deformation mode, and contact stress were obtained through a simulation. Based on the deformation of the flat and convex portions, the deformation modes were divided into three types. The deformation mode of the thin stainless gasket material has a higher probability of deformation in mode I when the aspect ratio of the length of the flat portion to the length of the convex portion, L/D, increases.

Abstract: In the previous study, the relationship between leakage and the contact width size that prevent leakage for 25A size of new metal gasket has been examined. In this study, large size of new metal gasket which are 50A, 80A and 100 A sizes were evaluated by using same approach of leak measurement and the relationship between leakage and the contact width. A new approach of leak measurement was performed to clarify the relationship between the presence of leak produced by the water pressure test and the amount of helium leak rate using helium leak test. Moreover, comparing the evaluation results of the relationship between the clamping load and the contact width by using the finite element method (FEM) analysis with the experimental results of the clamping load and the leakage, the contact width which affects the occurrence of leakages on new metal gasket was clarified. The results obtained for these gaskets indicated that the contact width is similar.

Abstract: The relationship of contact width and leakage had been found as design concept to optimize new metal gasket. By using this design concept, the limits of contact width for no leakage can be chosen. The optimize gasket shape can be developed by increasing of contact width. In this study, a gasket shape was optimized based on contact width as design concept and involving contact stress consideration. The design of experimentation (DOE) Taguchi method is used to analyses the effect of each parameter design and predict optimal design of new 25A metal gasket. The L18 orthogonal array was concerned to design experimental matrix for seven factors with three levels. The optimum design of gasket at 0 MPa mode is the model with OH = 4 mm, p₁ = 3.5 mm, p₂ = 4 mm, p₃ = 4 mm, t = 1.2 mm, R = 3.5 mm and h = 0.4 mm. The optimum design of gasket at 400 MPa mode is the model with OH = 3 mm, p₁ = 3.5 mm, p₂ = 4.5 mm, p₃ = 4.5 mm, t = 1.8 mm, R = 1.5 mm and h = 0.3 mm.

Abstract: A method to easily and economically manufacture more precise patterns compared with usual MEMS technique has been searched for. Under such circumstances, this research aims to clarify the formation of nano-scale protrusion structure produced by local anodic oxidation on Si wafer surface in expectation of the nano/micro mold production for nanoimprint lithography in future. In this report, the influences of contact width and distance between probe tip and Si wafer surface (distance between terminals) on the size and shape of protrusion patterns were examined in order to clarify the fundamental phenomena in local anodic oxidation. A scanning probe microscope equipped with a current measuring unit was utilized in local anodic oxidation experiments. As a result, it was confirmed that the size of generated protrusion structure became larger with increasing the contact width and became smaller with increasing the distance between probe tip and Si wafer surface. These facts will be useful in producing 3-D nanostructures in future.