This paper shows impermeable properties of H-jointed steel pipe sheet piles (SPSPs) with H-H joints under soil coexistence on impermeable walls used in coastal landfills. The authors have developed a number of technologies such as developing the H-jointed SPSPs and H-H joints for SPSP joint sections aimed at improving performance and widening application areas of SPSPs. Equivalent hydraulic conductivity of the H-jointed SPSPs with H-H joints under several soil coexistences was evaluated by experimental studies and it was clarified experimentally that H-jointed SPSPs with H-H joints can demonstrate the equivalent hydraulic conductivity of the 1 × 10-8cm/s order. This is because the coexistence soil particles are covered by the swelling of swellable waterproof materials inside the H-H joints.
{"title":"Experimental study on impermeable properties of H-jointed SPSPs with H-H joints under soil coexistence","authors":"S. Inazumi, M. Kimura, Takuzo Kuzu, T. Wakatsuki","doi":"10.2472/JSMS.59.74","DOIUrl":"https://doi.org/10.2472/JSMS.59.74","url":null,"abstract":"This paper shows impermeable properties of H-jointed steel pipe sheet piles (SPSPs) with H-H joints under soil coexistence on impermeable walls used in coastal landfills. The authors have developed a number of technologies such as developing the H-jointed SPSPs and H-H joints for SPSP joint sections aimed at improving performance and widening application areas of SPSPs. Equivalent hydraulic conductivity of the H-jointed SPSPs with H-H joints under several soil coexistences was evaluated by experimental studies and it was clarified experimentally that H-jointed SPSPs with H-H joints can demonstrate the equivalent hydraulic conductivity of the 1 × 10-8cm/s order. This is because the coexistence soil particles are covered by the swelling of swellable waterproof materials inside the H-H joints.","PeriodicalId":17366,"journal":{"name":"journal of the Japan Society for Testing Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91550100","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}
The main objective of this study is to clarify the influence of limestone aggregate on strength and drying shrinkage of concrete. Three kinds of limestone aggregates from different regions of Japan were used. The specimens were mixed with fine or coarse limestone and sandstone. As a result, the strengths and modulus of elasticity of concretes with limestone were larger than those of sandstone concretes. The drying shrinkage of concrete with fine or coarse limestone aggregate decreased clearly regardless of the region of production. Furthermore, the volume change of limestone aggregate in water and drying condition was quite smaller than that of sandstone aggregate. It is thought that the main cause of the reduction of drying shrinkage in concretes with limestone is the volume change of the aggregate itself.
{"title":"Influence of Limestone Aggregate on Strength and Drying Shrinkage of Concrete","authors":"M. Inoue, A. Carlos, H. Miura, T. Okamoto","doi":"10.2472/JSMS.59.769","DOIUrl":"https://doi.org/10.2472/JSMS.59.769","url":null,"abstract":"The main objective of this study is to clarify the influence of limestone aggregate on strength and drying shrinkage of concrete. Three kinds of limestone aggregates from different regions of Japan were used. The specimens were mixed with fine or coarse limestone and sandstone. As a result, the strengths and modulus of elasticity of concretes with limestone were larger than those of sandstone concretes. The drying shrinkage of concrete with fine or coarse limestone aggregate decreased clearly regardless of the region of production. Furthermore, the volume change of limestone aggregate in water and drying condition was quite smaller than that of sandstone aggregate. It is thought that the main cause of the reduction of drying shrinkage in concretes with limestone is the volume change of the aggregate itself.","PeriodicalId":17366,"journal":{"name":"journal of the Japan Society for Testing Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80559535","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}
We have so far shown that amorphous metals have many “unstable” atoms even at the equilibrium state, by local lattice instability analysis (LLIA) which discusses the positive definiteness of atomic elastic stiffness coefficients, Bαij. In the present study, we put our focus on the stability switching by the “probabilistic” fluctuation and the “deterministic” mechanical load. We have performed molecular dynamics simulations on Ni amorphous and evaluated the stability switching under no-load equilibrium as well as uniaxial tension. It is definitely true that the ratio of unstable atoms decreases/increases according to the system energy ; however, it is revealed that one-way change of stabilization or destabilization never occur but both positive and negative stability-switching are activated from their ratio under the equilibrium state. That is, a straightforward image of “stabilization/destabilization of local configuration” is not correct for structural change in amorphous metal but “shuffle of atomic arrangement” which involves atomic stabilization and destabilization simultaneously. In fact, we have proved that (1) both switching drastically increase at the slow-down point just before the stress-strain peak, (2) many stabilization/destabilization atoms can be found in the locally deformed area, and (3) such switching atoms actually feel hydrostatic tension in the dilated local configuration on the way of “shuffle”.
{"title":"Local Lattice Instability Analysis on Stability Switching in Amorphous Nickel","authors":"M. Nishimura, K. Yashiro, M. Arai","doi":"10.2472/JSMS.59.631","DOIUrl":"https://doi.org/10.2472/JSMS.59.631","url":null,"abstract":"We have so far shown that amorphous metals have many “unstable” atoms even at the equilibrium state, by local lattice instability analysis (LLIA) which discusses the positive definiteness of atomic elastic stiffness coefficients, Bαij. In the present study, we put our focus on the stability switching by the “probabilistic” fluctuation and the “deterministic” mechanical load. We have performed molecular dynamics simulations on Ni amorphous and evaluated the stability switching under no-load equilibrium as well as uniaxial tension. It is definitely true that the ratio of unstable atoms decreases/increases according to the system energy ; however, it is revealed that one-way change of stabilization or destabilization never occur but both positive and negative stability-switching are activated from their ratio under the equilibrium state. That is, a straightforward image of “stabilization/destabilization of local configuration” is not correct for structural change in amorphous metal but “shuffle of atomic arrangement” which involves atomic stabilization and destabilization simultaneously. In fact, we have proved that (1) both switching drastically increase at the slow-down point just before the stress-strain peak, (2) many stabilization/destabilization atoms can be found in the locally deformed area, and (3) such switching atoms actually feel hydrostatic tension in the dilated local configuration on the way of “shuffle”.","PeriodicalId":17366,"journal":{"name":"journal of the Japan Society for Testing Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79637151","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}
Electronic structures of (6,0), (8,0), and (10,0) single-walled boron nitride nanotubes (SWBNNTs) under tension, torsion and flattening are investigated using first-principles calculations. Energy bands and charge distributions of the SWBNNTs are calculated within the density-functional theory, and forces required to deform the SWBNNTs are estimated from the energy variation with deformation. Our calculations show that the tension, torsion and flattening decrease energy gaps of the SWBNNTs because of a decrease in the energy of the conduction band minimum (CBM). The decrease in the CBM energy is caused by an overlap of CBM charge densities between boron atoms. It is found that the flattening deformation leads to the larger decrease in energy gaps of the SWBNNTs with the smaller force than the tension and torsion.
{"title":"Deformation-Induced Electronic Structure Changes in Boron Nitride Nanotubes","authors":"Y. Kinoshita, N. Ohno","doi":"10.2472/JSMS.59.604","DOIUrl":"https://doi.org/10.2472/JSMS.59.604","url":null,"abstract":"Electronic structures of (6,0), (8,0), and (10,0) single-walled boron nitride nanotubes (SWBNNTs) under tension, torsion and flattening are investigated using first-principles calculations. Energy bands and charge distributions of the SWBNNTs are calculated within the density-functional theory, and forces required to deform the SWBNNTs are estimated from the energy variation with deformation. Our calculations show that the tension, torsion and flattening decrease energy gaps of the SWBNNTs because of a decrease in the energy of the conduction band minimum (CBM). The decrease in the CBM energy is caused by an overlap of CBM charge densities between boron atoms. It is found that the flattening deformation leads to the larger decrease in energy gaps of the SWBNNTs with the smaller force than the tension and torsion.","PeriodicalId":17366,"journal":{"name":"journal of the Japan Society for Testing Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85149365","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}
Mod.9Cr-1Mo steel has been used for boiler components in ultra-supercritical (USC) thermal power plants. The creep strength of welded joint of this steel decreases due to Type-IV creep cracking formed in heat affected zone (HAZ) at high temperatures. The present paper aims to clarify the damage process and microstructural degradation of the welded joint. Long-term creep tests for base metal, simulated HAZ and welded joints were conducted at 550, 600 and 650°C. Furthermore, creep tests of thick welded joint specimens were interrupted at several time steps for 600°C, 90MPa, and the damage distribution was measured. It is found that creep voids initiate at early stage of creep life (t/tr = 0.2), and coalesce into the crack at the later stage of life (t/tr = 0.9). Creep damages concentrate mostly at a quarter depths of the plate thickness in the fine-grained HAZ. The experimental creep damage distribution was compared with the computed one by using the damage mechanics analysis.
{"title":"Mod.9Cr-1Mo鋼溶接継手のクリープ損傷挙動","authors":"宏通 本郷, 正明 田淵, 永奎 李, 高橋 由紀夫","doi":"10.2472/JSMS.58.101","DOIUrl":"https://doi.org/10.2472/JSMS.58.101","url":null,"abstract":"Mod.9Cr-1Mo steel has been used for boiler components in ultra-supercritical (USC) thermal power plants. The creep strength of welded joint of this steel decreases due to Type-IV creep cracking formed in heat affected zone (HAZ) at high temperatures. The present paper aims to clarify the damage process and microstructural degradation of the welded joint. Long-term creep tests for base metal, simulated HAZ and welded joints were conducted at 550, 600 and 650°C. Furthermore, creep tests of thick welded joint specimens were interrupted at several time steps for 600°C, 90MPa, and the damage distribution was measured. It is found that creep voids initiate at early stage of creep life (t/tr = 0.2), and coalesce into the crack at the later stage of life (t/tr = 0.9). Creep damages concentrate mostly at a quarter depths of the plate thickness in the fine-grained HAZ. The experimental creep damage distribution was compared with the computed one by using the damage mechanics analysis.","PeriodicalId":17366,"journal":{"name":"journal of the Japan Society for Testing Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75894976","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}
R. Tanegashima, T. Shirosaka, H. Akebono, Masahiko Kato, A. Sugeta, K. Minoshima
In this study, fatigue properties of PM (Powder Metallurgy) soft magnetic materials were investigated by observation of the small fatigue crack propagation. The materials to which binder resin were added (Material BA) and three kinds of materials with different density (Material LD, MD and HD) were used in this study. Reversed plane bending fatigue tests were conducted at room temperature and small fatigue crack growths were studied in detail by means of replication technique. The fatigue strength became higher in the order, material HD, MD, LD, BA. In all specimens, cracks initiated at multi sites and each crack propagated with frequent deflection. Furthermore, cracks were coalesced repeatedly and specimen reached final fracture. Moreover, the difference between the materials was not recognized clearly in the da/dN-Kmax relationship. The maximum defect size, √area max, which was estimated by the statistics of extreme value became higher in the order, material BA, LD, MD, HD. As a result, the addition of the binder resin to PM alloy was not effective in improvement of fatigue strength. Furthermore, densification by increasing compacting pressure was effective in improvement of fatigue strength because the maximum defect size in each material became smaller. The ΔK0-Nf/√area max was estimated to consider whether the evaluation by the statistics of extreme value had propriety to the fatigue strength. Then, their curves were not corresponded. The disagreement was originated in the difference of coalescence frequency until the specimen reached to final fracture.
{"title":"Fatigue Crack Propagation of P/M Soft Magnetic Materials with a High-Resistance Surface Layer","authors":"R. Tanegashima, T. Shirosaka, H. Akebono, Masahiko Kato, A. Sugeta, K. Minoshima","doi":"10.2472/JSMS.58.853","DOIUrl":"https://doi.org/10.2472/JSMS.58.853","url":null,"abstract":"In this study, fatigue properties of PM (Powder Metallurgy) soft magnetic materials were investigated by observation of the small fatigue crack propagation. The materials to which binder resin were added (Material BA) and three kinds of materials with different density (Material LD, MD and HD) were used in this study. Reversed plane bending fatigue tests were conducted at room temperature and small fatigue crack growths were studied in detail by means of replication technique. The fatigue strength became higher in the order, material HD, MD, LD, BA. In all specimens, cracks initiated at multi sites and each crack propagated with frequent deflection. Furthermore, cracks were coalesced repeatedly and specimen reached final fracture. Moreover, the difference between the materials was not recognized clearly in the da/dN-Kmax relationship. The maximum defect size, √area max, which was estimated by the statistics of extreme value became higher in the order, material BA, LD, MD, HD. As a result, the addition of the binder resin to PM alloy was not effective in improvement of fatigue strength. Furthermore, densification by increasing compacting pressure was effective in improvement of fatigue strength because the maximum defect size in each material became smaller. The ΔK0-Nf/√area max was estimated to consider whether the evaluation by the statistics of extreme value had propriety to the fatigue strength. Then, their curves were not corresponded. The disagreement was originated in the difference of coalescence frequency until the specimen reached to final fracture.","PeriodicalId":17366,"journal":{"name":"journal of the Japan Society for Testing Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86817486","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}
Three kinds of copper thin films were fabricated by RF-magnetron sputtering. The target power was selected to be 10 and 150W to change the properties of the films. Thin glass sheet was used as a substrate. For the target power of 150W, the deposition time was selected to be 7 and 40min. The thickness was 0.6μm and 2.9μm, and the grain size measured was 243nm and 450nm, respectively. The grain size of thicker film was larger than that of thinner one. On the other hand, for the target power of 10W, the thickness and grain size were 2.4μm and 54nm, respectively. The grain size depends on the target power, too. The residual stress distribution in the films was measured by X-ray method. Several methods such as the grazing incidence X-ray diffraction method, the constant penetration depth method and the conventional sin2ψ method were adopted. The measured weighted average stress increased with increasing depth. After taking the maximum value at about 0.3μm from the surface, the value decreased with increasing depth. The stress distribution near the surface in the films deposited at 150W was almost identical irrespective of thickness. On the other hand, for the target power of 10W, the stress distribution shifted to compression side. The reason could be explained by the effect of the thermal residual stress. The real stress distribution was estimated by using the optimization technique. The stress took the maximum value at 0.5μm from the surface, and was compressive near the substrate.
{"title":"Measurement of Residual Stress Distribution in Sputtered Cu Thin Films by X-Ray Method","authors":"Y. Akiniwa, H. Kimura, Takuhisa Sakaue","doi":"10.2472/JSMS.58.575","DOIUrl":"https://doi.org/10.2472/JSMS.58.575","url":null,"abstract":"Three kinds of copper thin films were fabricated by RF-magnetron sputtering. The target power was selected to be 10 and 150W to change the properties of the films. Thin glass sheet was used as a substrate. For the target power of 150W, the deposition time was selected to be 7 and 40min. The thickness was 0.6μm and 2.9μm, and the grain size measured was 243nm and 450nm, respectively. The grain size of thicker film was larger than that of thinner one. On the other hand, for the target power of 10W, the thickness and grain size were 2.4μm and 54nm, respectively. The grain size depends on the target power, too. The residual stress distribution in the films was measured by X-ray method. Several methods such as the grazing incidence X-ray diffraction method, the constant penetration depth method and the conventional sin2ψ method were adopted. The measured weighted average stress increased with increasing depth. After taking the maximum value at about 0.3μm from the surface, the value decreased with increasing depth. The stress distribution near the surface in the films deposited at 150W was almost identical irrespective of thickness. On the other hand, for the target power of 10W, the stress distribution shifted to compression side. The reason could be explained by the effect of the thermal residual stress. The real stress distribution was estimated by using the optimization technique. The stress took the maximum value at 0.5μm from the surface, and was compressive near the substrate.","PeriodicalId":17366,"journal":{"name":"journal of the Japan Society for Testing Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80278427","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}
Isotherm curves of wood samples heated at lower temperatures 150, 175, and 200°C for various periods were examined on the basis of the characterization theories of adsorption, Hailwood and Horrobin theory, Dubinin-Radushkevich theory, and Neimark theory. The adsorption properties were characterized by the parameters of their theories. Their properties without the fractal dimensionality were presented by weight change regardless of heating temperature and had the transition point at weight change = –0.2.
{"title":"Effects of Heating at Lower Temperature on Water Adsorption Behavior for Wood","authors":"M. Shiga, T. Nakano","doi":"10.2472/JSMS.58.175","DOIUrl":"https://doi.org/10.2472/JSMS.58.175","url":null,"abstract":"Isotherm curves of wood samples heated at lower temperatures 150, 175, and 200°C for various periods were examined on the basis of the characterization theories of adsorption, Hailwood and Horrobin theory, Dubinin-Radushkevich theory, and Neimark theory. The adsorption properties were characterized by the parameters of their theories. Their properties without the fractal dimensionality were presented by weight change regardless of heating temperature and had the transition point at weight change = –0.2.","PeriodicalId":17366,"journal":{"name":"journal of the Japan Society for Testing Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84530689","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}
In order to investigate the effect of humidity on fatigue strength of an extruded and age-hardened Al alloy 7075-T6, rotating bending fatigue tests were carried out using plain specimens and circumferential notched ones with notch radii of 1.0, 0.1 and 0.05mm in environments of relative humidity 25% and 85%. Fatigue strength was decreased by high humidity, except for notched specimen with notch radius of 0.1mm. Fatigue limit for notched specimen with notch radius of 0.05mm was very high in low humidity. Notch sensitivity for crack initiation was low and the one for crack propagation was reversely high in high humidity. Branch points were 0.05-0.1mm in low humidity and about 0.3mm in high one, respectively. Crack in sharply notched specimen tended to propagate in shear mode in low humidity with decreases in stress level, though all of crack propagations were in tensile mode in high humidity. This was a main reason for high fatigue limit in notched specimen with notch radius of 0.05mm in low humidity.
{"title":"Effect of Humidity on Fatigue Strength of Notched Age-Hardened Al Alloy","authors":"N. Kawagoishi, T. Kanemaru, K. Kariya, Y. Ohzono","doi":"10.2472/JSMS.58.860","DOIUrl":"https://doi.org/10.2472/JSMS.58.860","url":null,"abstract":"In order to investigate the effect of humidity on fatigue strength of an extruded and age-hardened Al alloy 7075-T6, rotating bending fatigue tests were carried out using plain specimens and circumferential notched ones with notch radii of 1.0, 0.1 and 0.05mm in environments of relative humidity 25% and 85%. Fatigue strength was decreased by high humidity, except for notched specimen with notch radius of 0.1mm. Fatigue limit for notched specimen with notch radius of 0.05mm was very high in low humidity. Notch sensitivity for crack initiation was low and the one for crack propagation was reversely high in high humidity. Branch points were 0.05-0.1mm in low humidity and about 0.3mm in high one, respectively. Crack in sharply notched specimen tended to propagate in shear mode in low humidity with decreases in stress level, though all of crack propagations were in tensile mode in high humidity. This was a main reason for high fatigue limit in notched specimen with notch radius of 0.05mm in low humidity.","PeriodicalId":17366,"journal":{"name":"journal of the Japan Society for Testing Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84427169","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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