著者

太田 高裕

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.851, pp.17-00153-17-00153, 2017 (Released:2017-07-25)

参考文献数

17

被引用文献数

3

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Shot peening is widely applied in the automotive and aerospace industries in order to improve the fatigue strength of the metal components by compressive residual stress. In the case of large components, the peening process is generally performed by moving peening equipment that follows a trajectory on the component surface by means of a robot. In order to construct a robot program for the shot peening of complex components, this study aimed to obtain a functional approximation of the impact pressure distribution in the shot stream. The impact pressure distributions were measured with pressure measurement films (Prescale) and a pressure distribution mapping system. The dependence of the mean impact pressure in the shot stream on the shot mass was in good agreement with the dependence of the arc height of the Almen strip on the shot mass. The impact pressure distributions using various shot masses and standoff distances were measured and approximated by modified Gaussian distribution functions, which included the saturation curve. Three coefficients in the modified Gaussian distribution functions depended on the shot mass and the standoff distance. The modified Gaussian distribution functions were used to determine the impact pressure distributions of a twice-shot peened samples. These calculated values were in good agreement with the experimental results. However, for tilted shot peening, the impact pressure distributions were more complex because the standoff distance at each position on the film was different. The impact pressure distributions of the tilted conditions calculated by the modified Gaussian distribution function, which considered the variation in the standoff distance, were in good agreement with the experimental results for a tilt angle ranging from 30° to 90°.

著者

太田 高裕 河野 亮 小﨑 貴史

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.849, pp.16-00451-16-00451, 2017 (Released:2017-05-25)

参考文献数

12

被引用文献数

2

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Peen forming has been widely used in the aerospace industry for forming complex components of large thin wings. The conventional peen forming using spherical shots shows a tendency to form the spherical surface because of its axisymmetric plastic strain. In this study, a new peen forming method using rectangular solid pins is developed. It is possible to produce the different distribution between x direction (short side of pin) plastic strain and z direction (long side of pin) plastic strain. The anisotropic plastic strain distribution causes smaller curvature radius of x direction section than that of z direction section. In order to verify the anisotropic plastic strain distribution in this method, the effects of pin tip shape are analyzed by dynamic explicit finite element method. The ratios of x direction plastic strain to z direction plastic strain increase with decreasing pin tip radius. It is confirmed that anisotropic double-curved surfaces are produced by drop tests using multi- rectangular-solid pins.