Pub Date : 1996-01-15DOI: 10.1299/JSMEA1993.39.1_55
Y. Pala
In this study, internal stresses of an elliptical ring sector with the cross section of a multi connected region composed of two confocal ellipses, subjected to pure bending are analyzed. Gohner's method is used for analysis and therefore, some difficulties caused by elliptical coordinates are eliminated. The analysis is limited to determining the first correction to the initial stress state for pure bending of an elliptical ring sector with the cross section of two confocal ellipses.
{"title":"Pure Bending of Elliptical Ring Sector with Cross Section of Multi-Connected Region Composed of Confocal Ellipses","authors":"Y. Pala","doi":"10.1299/JSMEA1993.39.1_55","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.1_55","url":null,"abstract":"In this study, internal stresses of an elliptical ring sector with the cross section of a multi connected region composed of two confocal ellipses, subjected to pure bending are analyzed. Gohner's method is used for analysis and therefore, some difficulties caused by elliptical coordinates are eliminated. The analysis is limited to determining the first correction to the initial stress state for pure bending of an elliptical ring sector with the cross section of two confocal ellipses.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114829339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-15DOI: 10.1299/JSMEA1993.39.1_42
T. Shibuya, A. Ohtomo
In this paper, the axisymmetric torsion problem of a compound infinite cylinder with an external annular crack is considered on the basis of the three-dimensional theory of elasticity. This problem is reduced to the solution of an infinite system of simultaneous equations. The coefficient matrix is given by the product of three matrices including an inverse matrix. Numerical results are illustrated for the distributions of displacement and shear stress and for the variations of the stress intensity factor K III for various ratios of inner to outer material shear modulus and various ratios of inner to outer radius of the cylinder.
{"title":"Torsion of Compound Cylinder with an External Annular Crack","authors":"T. Shibuya, A. Ohtomo","doi":"10.1299/JSMEA1993.39.1_42","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.1_42","url":null,"abstract":"In this paper, the axisymmetric torsion problem of a compound infinite cylinder with an external annular crack is considered on the basis of the three-dimensional theory of elasticity. This problem is reduced to the solution of an infinite system of simultaneous equations. The coefficient matrix is given by the product of three matrices including an inverse matrix. Numerical results are illustrated for the distributions of displacement and shear stress and for the variations of the stress intensity factor K III for various ratios of inner to outer material shear modulus and various ratios of inner to outer radius of the cylinder.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129791342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-15DOI: 10.1299/JSMEA1993.39.1_135
K. Sakino, J. Shioiri
In the previous work, strain rate change tests were conducted for high-purity polycrystalline aluminum at very high strain rates. Here we present the results of reduction tests carried out for copper. The experimental apparatus devised in the previous work is used to attain a sufficiently steep reduction in the strain rate. The flow stress obtained from the reduction tests is analyzed by means of the deconvolution method. The results indicate that the instantaneous strain rate plays a more important role than the strain rate history for the dynamic flow stress at very high strain rates where a steep increase in the strain rate sensitivity of the flow stress is observed. The above-mentioned results are the same as those found in the previous work.
{"title":"Effect of steep reduction in strain rate on the dynamic flow stress of copper at very high strain rates","authors":"K. Sakino, J. Shioiri","doi":"10.1299/JSMEA1993.39.1_135","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.1_135","url":null,"abstract":"In the previous work, strain rate change tests were conducted for high-purity polycrystalline aluminum at very high strain rates. Here we present the results of reduction tests carried out for copper. The experimental apparatus devised in the previous work is used to attain a sufficiently steep reduction in the strain rate. The flow stress obtained from the reduction tests is analyzed by means of the deconvolution method. The results indicate that the instantaneous strain rate plays a more important role than the strain rate history for the dynamic flow stress at very high strain rates where a steep increase in the strain rate sensitivity of the flow stress is observed. The above-mentioned results are the same as those found in the previous work.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122110656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-15DOI: 10.1299/JSMEA1993.39.1_1
M. Goto, N. Kawagoishi, H. Nisitani, H. Miyagawa
In order to investigate the scatter characteristics of growth rate for small cracks rotating-bending fatigue tests of smooth specimens were carried out using 0.21% carbon steels with different ferrite grain sizes. Fifteen to eighteen specimens were fatigued at each stress amplitude, and the growth rate of a crack which led to the fracture was measured for all the specimens. The growth data were analyzed statistically. The results show that the growth rate for each crack length can be expressed by a three- or two-parameter Weibull distribution. The CV, coefficient of variance, for crack growth rate distribution was calculated, and using the CV the relations between the scatter in growth rate and the ferrite grain size were investigated.
{"title":"STATISTICAL PROPERTY OF SMALL-CRACK GROWTH RATE IN 0.21% C STEEL SMOOTH SPECIMENS HAVING DIFFERENT FERRITE GRAIN SIZES","authors":"M. Goto, N. Kawagoishi, H. Nisitani, H. Miyagawa","doi":"10.1299/JSMEA1993.39.1_1","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.1_1","url":null,"abstract":"In order to investigate the scatter characteristics of growth rate for small cracks rotating-bending fatigue tests of smooth specimens were carried out using 0.21% carbon steels with different ferrite grain sizes. Fifteen to eighteen specimens were fatigued at each stress amplitude, and the growth rate of a crack which led to the fracture was measured for all the specimens. The growth data were analyzed statistically. The results show that the growth rate for each crack length can be expressed by a three- or two-parameter Weibull distribution. The CV, coefficient of variance, for crack growth rate distribution was calculated, and using the CV the relations between the scatter in growth rate and the ferrite grain size were investigated.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121024297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-15DOI: 10.1299/JSMEA1993.39.1_86
Kaishin Liu, T. Yokoyama
The present paper is concerned with a numerical and experimental investigation of the transient torsional waves in a semi-infinite stepped circular bar subjected to torsional impact loading at its free end. The differential equations governing the dynamic torsional deformation of the stepped bar are solved by means of the method of numerical integration along bi-characteristics. The stability and convergence of the numerical solutions are checked by estimating the total energy of the system. The torsional elastic wave-propagation experiments for the stepped bar are performed using a modified version of the torsional Hopkinson bar apparatus. The numerical results for the torsional shear strain-time profiles on the surface before and after the discontinuity of cross section of the stepped bar are shown to be in reasonable agreement with the experimental results. The limitations of the classical one-dimensional torsional wave equation for thin rods are examined by determining the two-dimensional distributions of the dynamic torsional shear stresses in the vicinity of the discontinuity of the cross section of the stepped bar.
{"title":"Transient Torsional Waves in Stepped Circular Bars : Two-Dimensional Numerical Analysis and Its Experimental Verification","authors":"Kaishin Liu, T. Yokoyama","doi":"10.1299/JSMEA1993.39.1_86","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.1_86","url":null,"abstract":"The present paper is concerned with a numerical and experimental investigation of the transient torsional waves in a semi-infinite stepped circular bar subjected to torsional impact loading at its free end. The differential equations governing the dynamic torsional deformation of the stepped bar are solved by means of the method of numerical integration along bi-characteristics. The stability and convergence of the numerical solutions are checked by estimating the total energy of the system. The torsional elastic wave-propagation experiments for the stepped bar are performed using a modified version of the torsional Hopkinson bar apparatus. The numerical results for the torsional shear strain-time profiles on the surface before and after the discontinuity of cross section of the stepped bar are shown to be in reasonable agreement with the experimental results. The limitations of the classical one-dimensional torsional wave equation for thin rods are examined by determining the two-dimensional distributions of the dynamic torsional shear stresses in the vicinity of the discontinuity of the cross section of the stepped bar.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117350807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-15DOI: 10.1299/JSMEA1993.39.1_18
M. Okane, T. Satoh, Y. Mutoh, Shogo Suzuki
Fretting fatigue tests were carried out using HIP-sintered silicon nitride to study the effect of relative slip amplitude between the specimen and the contact pad on fretting fatigue behavior. Fretting fatigue strength decreased with increasing relative slip amplitude. Application of static contact without fretting motion had no influence on static fatigue strength. Therefore, fretting action with relative slip is essential for the degradation of fatigue strength. Fretting fatigue life prediction based on fracture mechanics analysis was also carried out, where the frictional force between the specimen and the contact pad was taken into consideration. The predicted fretting fatigue lives agreed well with the experimental results.
{"title":"Effect of Relative Slip Amplitude on Fretting Fatigue Behavior of Silicon Nitride","authors":"M. Okane, T. Satoh, Y. Mutoh, Shogo Suzuki","doi":"10.1299/JSMEA1993.39.1_18","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.1_18","url":null,"abstract":"Fretting fatigue tests were carried out using HIP-sintered silicon nitride to study the effect of relative slip amplitude between the specimen and the contact pad on fretting fatigue behavior. Fretting fatigue strength decreased with increasing relative slip amplitude. Application of static contact without fretting motion had no influence on static fatigue strength. Therefore, fretting action with relative slip is essential for the degradation of fatigue strength. Fretting fatigue life prediction based on fracture mechanics analysis was also carried out, where the frictional force between the specimen and the contact pad was taken into consideration. The predicted fretting fatigue lives agreed well with the experimental results.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130201968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-15DOI: 10.1299/JSMEA1993.39.1_129
H. Yanai, N. Kishine, Y. Komaba, Y. Murakami
In order to evaluate the mechanical properties of a very thin film, this paper proposes a convenient method for separately determining Young's moduli of two thin films of a magnetic recording medium. Furthermore, the particular stress distribution inside a magnetic recording film (two bonded thin films) is analyzed. The internal stress in the medium is not uniform when the medium is subjected to unidirectional tension. The analysis shows that the difference in Poisson's ratio on two thin films causes flexure of the two bonded films under tension, as well as shearing stress at the interface between the magnetic layer and the substrate. Since the shearing stress may cause fatigue damage of the tape edge, detailed FEM analysis on its distribution is carried out.
{"title":"Measurement of Young's Modulus and Stress Analysis of a Magnetic Thin Film","authors":"H. Yanai, N. Kishine, Y. Komaba, Y. Murakami","doi":"10.1299/JSMEA1993.39.1_129","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.1_129","url":null,"abstract":"In order to evaluate the mechanical properties of a very thin film, this paper proposes a convenient method for separately determining Young's moduli of two thin films of a magnetic recording medium. Furthermore, the particular stress distribution inside a magnetic recording film (two bonded thin films) is analyzed. The internal stress in the medium is not uniform when the medium is subjected to unidirectional tension. The analysis shows that the difference in Poisson's ratio on two thin films causes flexure of the two bonded films under tension, as well as shearing stress at the interface between the magnetic layer and the substrate. Since the shearing stress may cause fatigue damage of the tape edge, detailed FEM analysis on its distribution is carried out.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127374955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-15DOI: 10.1299/JSMEA1993.39.1_99
Zhihong Guo, O. Watanabe
We discuss the accuracy of finite-element solutions for metals possessing dominant plasticity, resulting in an incompressible response in a large deformation field. It is known that poor numerical solutions are obtained for the constrained problem due to incompressibility of deformed metals, but they can be improved by selecting an appropriate shape function and numerical integration technique, as well as by applying the mixed method derived from Lagrangian multipliers. Many studies have been made for rigid-plastic finite-element solutions so far, but large-deformation elastoplastic structural analysis is rarely discussed in the literature. In this work, we discuss the advantages of such techniques in large-deformation analysis using the Jaumann stress rate and isotropic hardening hypoelasticity model.
{"title":"Study on Accuracy of Finite-Element Solutions in Elastoplastic Large Deformation : Effects of Shape Function and Numerical Integration, and Application of Mixed Method","authors":"Zhihong Guo, O. Watanabe","doi":"10.1299/JSMEA1993.39.1_99","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.1_99","url":null,"abstract":"We discuss the accuracy of finite-element solutions for metals possessing dominant plasticity, resulting in an incompressible response in a large deformation field. It is known that poor numerical solutions are obtained for the constrained problem due to incompressibility of deformed metals, but they can be improved by selecting an appropriate shape function and numerical integration technique, as well as by applying the mixed method derived from Lagrangian multipliers. Many studies have been made for rigid-plastic finite-element solutions so far, but large-deformation elastoplastic structural analysis is rarely discussed in the literature. In this work, we discuss the advantages of such techniques in large-deformation analysis using the Jaumann stress rate and isotropic hardening hypoelasticity model.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116584235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-15DOI: 10.1299/JSMEA1993.39.1_49
H. Ohta, N. Saito, H. Miura, N. Okamoto
The stress development mechanism during local thermal oxidation of a silicon substrate is discussed based on the predicted results using a two-dimensional thermal oxidation process simulation program OXSIM2D developed by the authors. Predicted stress change during the oxidation agrees well with the measured data obtained by means of micro-Raman spectroscopy. There are three main factors which play important roles in stress delelopment in the newly grown oxide film and the substrate. They are the volume expansion of the oxide film, the viscosity of the oxide film, and the bending of the silicon nitride film which is used as the oxidation barrier. These factors give rise to the complicated stress distribution and the stress change near the edge of the nitride film during thermal oxidation.
{"title":"Stress Analysis in Silicon Substrates during Thermal Oxidation","authors":"H. Ohta, N. Saito, H. Miura, N. Okamoto","doi":"10.1299/JSMEA1993.39.1_49","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.1_49","url":null,"abstract":"The stress development mechanism during local thermal oxidation of a silicon substrate is discussed based on the predicted results using a two-dimensional thermal oxidation process simulation program OXSIM2D developed by the authors. Predicted stress change during the oxidation agrees well with the measured data obtained by means of micro-Raman spectroscopy. There are three main factors which play important roles in stress delelopment in the newly grown oxide film and the substrate. They are the volume expansion of the oxide film, the viscosity of the oxide film, and the bending of the silicon nitride film which is used as the oxidation barrier. These factors give rise to the complicated stress distribution and the stress change near the edge of the nitride film during thermal oxidation.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133809834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-15DOI: 10.1299/JSMEA1993.39.1_78
K. Kaizu, S. Tokunaga, S. Tanimura
A numerical method is presented to analyze three-dimensional stress waves in an elastic/viscoplastic thick plate, when oblique impact is applied to the surface of the thick plate at various impact angles. For the numerical analysis, the finite difference method based on integration along the bicharacteristics is employed. From the numerical results obtained for various loading conditions, the effect of the impact angle on impact fracture is examined. It is also demonstrated that the dynamic behavior of the plate due to oblique impact can be examined in detail using this method.
{"title":"Dynamic behavior of thick plates due to oblique impact : (Numerical analysis of three-dimensional stress waves in an elastic/viscoplastic body)","authors":"K. Kaizu, S. Tokunaga, S. Tanimura","doi":"10.1299/JSMEA1993.39.1_78","DOIUrl":"https://doi.org/10.1299/JSMEA1993.39.1_78","url":null,"abstract":"A numerical method is presented to analyze three-dimensional stress waves in an elastic/viscoplastic thick plate, when oblique impact is applied to the surface of the thick plate at various impact angles. For the numerical analysis, the finite difference method based on integration along the bicharacteristics is employed. From the numerical results obtained for various loading conditions, the effect of the impact angle on impact fracture is examined. It is also demonstrated that the dynamic behavior of the plate due to oblique impact can be examined in detail using this method.","PeriodicalId":143127,"journal":{"name":"JSME international journal. Series A, mechanics and material engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130759561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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