The Experts below are selected from a list of 152109 Experts worldwide ranked by ideXlab platform
E Niemi - One of the best experts on this subject based on the ideXlab platform.
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Analysis of the stress Concentration Factor for a shallow notch by the slip-line field method
International Journal of Fatigue, 1997Co-Authors: M. Zheng, E NiemiAbstract:The relationships correlating the local stress and strain at the tip of a notch, the nominal stress expressed by the so called Neuber's rule and Moski and Glinka's equivalent energy density method are studied for a shallow notch,using the slip-line field method proposed in plastic mechanics, and an elastic-plastic solution for the area close to the notch. An elastic-perfect plastic material model is also used. It is found that for lower stress amplitude Moski and Glinka's method is with a good accuracy; however, the relative deviations of the actual stress Concentration Factors calculated by these two methods to the theoretical stress Concentration Factor are not small, even up to 20% for higher stress amplitude as the size of the plastic zone around the notch approaches the value of the radius of the notch curvature. While the geometric mean of the two expressions mentioned above can be considered as a reasonable expression to correlate the local stress-strain and the nominal stress, and thus the corresponding actual equivalent stress Concentration Factor can be evaluated, of which the relative deviations to the theoretical stress Concentration Factor is shown to be
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analysis of the stress Concentration Factor for a shallow notch by the slip line field method
International Journal of Fatigue, 1997Co-Authors: M. Zheng, E NiemiAbstract:The relationships correlating the local stress and strain at the tip of a notch, the nominal stress expressed by the so called Neuber's rule and Moski and Glinka's equivalent energy density method are studied for a shallow notch,using the slip-line field method proposed in plastic mechanics, and an elastic-plastic solution for the area close to the notch. An elastic-perfect plastic material model is also used. It is found that for lower stress amplitude Moski and Glinka's method is with a good accuracy; however, the relative deviations of the actual stress Concentration Factors calculated by these two methods to the theoretical stress Concentration Factor are not small, even up to 20% for higher stress amplitude as the size of the plastic zone around the notch approaches the value of the radius of the notch curvature. While the geometric mean of the two expressions mentioned above can be considered as a reasonable expression to correlate the local stress-strain and the nominal stress, and thus the corresponding actual equivalent stress Concentration Factor can be evaluated, of which the relative deviations to the theoretical stress Concentration Factor is shown to be <5%, if the size of plastic zone close to the notch is not greater than the value of the radius of curvature of the notch.
M. Zheng - One of the best experts on this subject based on the ideXlab platform.
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Analysis of the stress Concentration Factor for a shallow notch by the slip-line field method
International Journal of Fatigue, 1997Co-Authors: M. Zheng, E NiemiAbstract:The relationships correlating the local stress and strain at the tip of a notch, the nominal stress expressed by the so called Neuber's rule and Moski and Glinka's equivalent energy density method are studied for a shallow notch,using the slip-line field method proposed in plastic mechanics, and an elastic-plastic solution for the area close to the notch. An elastic-perfect plastic material model is also used. It is found that for lower stress amplitude Moski and Glinka's method is with a good accuracy; however, the relative deviations of the actual stress Concentration Factors calculated by these two methods to the theoretical stress Concentration Factor are not small, even up to 20% for higher stress amplitude as the size of the plastic zone around the notch approaches the value of the radius of the notch curvature. While the geometric mean of the two expressions mentioned above can be considered as a reasonable expression to correlate the local stress-strain and the nominal stress, and thus the corresponding actual equivalent stress Concentration Factor can be evaluated, of which the relative deviations to the theoretical stress Concentration Factor is shown to be
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analysis of the stress Concentration Factor for a shallow notch by the slip line field method
International Journal of Fatigue, 1997Co-Authors: M. Zheng, E NiemiAbstract:The relationships correlating the local stress and strain at the tip of a notch, the nominal stress expressed by the so called Neuber's rule and Moski and Glinka's equivalent energy density method are studied for a shallow notch,using the slip-line field method proposed in plastic mechanics, and an elastic-plastic solution for the area close to the notch. An elastic-perfect plastic material model is also used. It is found that for lower stress amplitude Moski and Glinka's method is with a good accuracy; however, the relative deviations of the actual stress Concentration Factors calculated by these two methods to the theoretical stress Concentration Factor are not small, even up to 20% for higher stress amplitude as the size of the plastic zone around the notch approaches the value of the radius of the notch curvature. While the geometric mean of the two expressions mentioned above can be considered as a reasonable expression to correlate the local stress-strain and the nominal stress, and thus the corresponding actual equivalent stress Concentration Factor can be evaluated, of which the relative deviations to the theoretical stress Concentration Factor is shown to be <5%, if the size of plastic zone close to the notch is not greater than the value of the radius of curvature of the notch.
Jie Yu - One of the best experts on this subject based on the ideXlab platform.
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effect of characteristic parameters of pitting on strength and stress Concentration Factor of cable steel wire
Construction and Building Materials, 2020Co-Authors: Rou Li, Changqing Miao, Jie YuAbstract:Abstract In order to investigate the influence of characteristic parameters of pits on the strength and stress Concentration Factor of cable steel wire, 198 cable steel wires with pits were manually prepared. The variation law of stress distribution of steel wire was analyzed, and its relationships with strength and stress Concentration Factor were studied through tensile test and finite element analysis. On this basis, the calculation model of yield strength and stress Concentration Factor of steel wire with pits was established. The influences of secondary pits on stress distribution and stress Concentration Factor of steel wire were also analyzed. The results showed that the strength of steel wire decreased gradually and the stress Concentration Factor increased with the increase of pit depth and the decrease of pit width. The change of pit clearance on the same side had no obvious effect on the strength and stress Concentration Factor of steel wire, but it had significant effect when located on the opposite side. The strength and stress Concentration Factor of steel wire with adjacent pits usually depended on the depth of the larger pits. The pits with depth to width ratio of 1 to 2 had the most significant effect on the stress Concentration Factor. Moreover, secondary pit would change the stress distribution, and the position of maximum stress changed from near the mouth to the bottom of the pit. The stress Concentration Factor of secondary pit was obviously higher than that of steel wire with only the primary pit.
Naoaki Noda - One of the best experts on this subject based on the ideXlab platform.
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Strain rate Concentration Factor for flat notched specimen to predict impact strength for polymeric materials
Mechanics of Materials, 2019Co-Authors: Naoaki Noda, Rei Takaki, Yunong Shen, Akane Inoue, Daichi Akagi, Yasushi Takase, Yoshikazu Sano, Pedro GalvezAbstract:Abstract In this study, the impact strength of notched specimens of polymeric materials was studied by using high speed tensile test. Focusing on the strain rate at the notch root, the final fracture elongation was expressed in terms of the time-temperature superposition principle. Fracture behavior under various impact speed and temperature can be predicted by mean of the obtained master curves. The validity of the elastic strain rate Concentration Factor was confirmed through elastic-plastic analyses for both polycarbonate and polydimethylsiloxane copolymerized polycarbonate. It is found that the strain rate Concentration Factor can be estimated from the stress Concentration Factor for flat test specimens.
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relationship between strain rate Concentration Factor and stress Concentration Factor
Theoretical and Applied Fracture Mechanics, 2017Co-Authors: Naoaki Noda, Tomohiro Ikeda, Rei Takaki, Yunong Shen, Daichi Akagi, Yoshikazu Sano, Yasushi TakaseAbstract:Abstract In this study, the strain rate Concentration is considered for high speed tensile test, which is now being recognized as a standard testing method. To evaluate the impact strength of engineering materials under high impact speed, Izod and Charpy tests are unsuitable since they cannot control the impact speeds and therefore do not coincide with the real failure of real products. For smooth specimens, the strain rate can be determined from the tensile speed u / t and specimen length l as e smooth = u / tl . For notched specimens, however, the strain rate at the notch root e notch should be analyzed accurately. In this study, therefore, the strain rate Concentration Factor defined as K t e = e notch / e smooth is studied with varying the notch geometry and specimen length. It is found that the strain Concentration Factor K t e can be estimated from stress Concentration Factor K t ∗ .
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Strain rate Concentration Factor in comparison with stress Concentration Factor of a circumferential notch in a round bar specimen
Transactions of the JSME (in Japanese), 2017Co-Authors: Naoaki Noda, Tomohiro Ikeda, Rei Takaki, Yunong Shen, Daichi Akagi, Yoshikazu Sano, Yasushi TakaseAbstract:High-speed tensile testing is now being recognized as a standard testing method for evaluating the impact strength of engineering materials. The impact speeds of Izod and Charpy tests cannot be controlled and therefore do not correspond to the real failure of real products. The brittle-ductile transition of structural materials is affected by the temperature and loading speed. In the high-speed tensile test, it is necessary to obtain the strain rate at the notch root accurately to understand the effect of impact load. For smooth specimens, the strain rate can be determined from the tensile speed u/t and specimen length l as εsmooth = u/tl. For notched specimens, however, the strain rate at the notch root εnotch should be analyzed accurately. In this study, therefore, the strain rate Concentration Factor defined as Ktε = εnotch/εsmooth is studied with varying the notch geometry. To predict the strain rate Concentration Factor Ktε accurately, the relationship between Ktε and the stress Concentration Factor Kt* = σmax/σgross is investigated. Here, σgross is the remote tensile stress and P is the tensile load. It is found that the strain Concentration Factor Ktε can be estimeted from stress Concentration Factor Kt* when the relative notch depth 2t/D≦0.5 (t : notch depth, D : the specimen diameter)
Pedro Galvez - One of the best experts on this subject based on the ideXlab platform.
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Strain rate Concentration Factor for flat notched specimen to predict impact strength for polymeric materials
Mechanics of Materials, 2019Co-Authors: Naoaki Noda, Rei Takaki, Yunong Shen, Akane Inoue, Daichi Akagi, Yasushi Takase, Yoshikazu Sano, Pedro GalvezAbstract:Abstract In this study, the impact strength of notched specimens of polymeric materials was studied by using high speed tensile test. Focusing on the strain rate at the notch root, the final fracture elongation was expressed in terms of the time-temperature superposition principle. Fracture behavior under various impact speed and temperature can be predicted by mean of the obtained master curves. The validity of the elastic strain rate Concentration Factor was confirmed through elastic-plastic analyses for both polycarbonate and polydimethylsiloxane copolymerized polycarbonate. It is found that the strain rate Concentration Factor can be estimated from the stress Concentration Factor for flat test specimens.