Pub Date : 1900-01-01DOI: 10.1299/transjsme.21-00172
Yuta Kasuya, Naoki Iinuma, Ryo Shirata, Hiroshige Sato, Y. Kakinuma
Ultrasonic abrasive machining is a machining method in which an ultrasonically-vibrated tool presses the workpiece via free abrasive grains and induces hammering motion of free abrasives. This machining technique is especially applicable to hardand-brittle materials such as ceramic matrix composites and sufficient machining speed is practically achieved by performing micro-brittle fractures tens of thousands of times per second. Nevertheless, there are few studies that quantitatively evaluate the parameters of this machining method and their interactions. The problem is that this machining process is conducted manually and the machining conditions are determined by the experience of an operator. Hence, derivation of conditions to improve machining efficiency is required. In this study, the factor effects and their interactions among machining pressure, oscillator power and slurry flow, which are the typical parameters of ultrasonic abrasive machining, were evaluated by analysis of variance and the related experiments in monolithic SiC. As a result of analysis of variance and the related experiments, it was shown that the combination of machining pressure of 135 g/mm, oscillator power of 100 W and slurry flow of 2500 mL/min remarkably improves the machining efficiency in monolithic SiC. It was also clarified that there are significant interactions between the machining pressure and the oscillator power and between the machining pressure and the slurry flow, respectively.
{"title":"Performance evaluation of ultrasonic abrasive machining by analysis of variance","authors":"Yuta Kasuya, Naoki Iinuma, Ryo Shirata, Hiroshige Sato, Y. Kakinuma","doi":"10.1299/transjsme.21-00172","DOIUrl":"https://doi.org/10.1299/transjsme.21-00172","url":null,"abstract":"Ultrasonic abrasive machining is a machining method in which an ultrasonically-vibrated tool presses the workpiece via free abrasive grains and induces hammering motion of free abrasives. This machining technique is especially applicable to hardand-brittle materials such as ceramic matrix composites and sufficient machining speed is practically achieved by performing micro-brittle fractures tens of thousands of times per second. Nevertheless, there are few studies that quantitatively evaluate the parameters of this machining method and their interactions. The problem is that this machining process is conducted manually and the machining conditions are determined by the experience of an operator. Hence, derivation of conditions to improve machining efficiency is required. In this study, the factor effects and their interactions among machining pressure, oscillator power and slurry flow, which are the typical parameters of ultrasonic abrasive machining, were evaluated by analysis of variance and the related experiments in monolithic SiC. As a result of analysis of variance and the related experiments, it was shown that the combination of machining pressure of 135 g/mm, oscillator power of 100 W and slurry flow of 2500 mL/min remarkably improves the machining efficiency in monolithic SiC. It was also clarified that there are significant interactions between the machining pressure and the oscillator power and between the machining pressure and the slurry flow, respectively.","PeriodicalId":341040,"journal":{"name":"Transactions of the JSME (in Japanese)","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116585768","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 : 1900-01-01DOI: 10.1299/transjsme.20-00045
Hideto Taoka, Nobuo Ishida, T. Toriyama
A test on the water tightness performance of watertight doors was conducted to obtain knowledge on the fragility beyond design conditions. The performance test was conducted on three types of standard single-swinging watertight doors used for nuclear facilities. Assuming tsunami conditions during an earthquake, the water pressure and the shear strain caused by horizontal force were applied on the watertight door during the test. A shear strain of up to 4000 μ and a water pressure of up to 0.3 MPa were loaded step by step. The water that leaked from the door was measured at each step. The test results showed that the water pressure was related to the leakage quantities, but no clear relationship was observed between the shear strain and leakage quantities. Subsequently, a confirmation test was conducted focusing on the sealed portion of the watertight doors. The condition of the packing and the leakage of the seal during water pressure loading was observed. Consequently, we found that a large quantity of leakage under water pressure was caused by protrusion of the packing, and we inferred that leakage would occur by the same mechanism in actual watertight doors. Using the test results, we considered a method for evaluating the water tightness limit of the door. An analysis on the performance test was conducted using the evaluation method. The result showed that the water pressure that formed a leakage path in the analysis was consistent with the water pressure that caused a large quantity of leakage in the test.
{"title":"Examination and analysis of the water tightness of watertight doors in nuclear facilities (Water tightness of the watertight doors beyond design conditions)","authors":"Hideto Taoka, Nobuo Ishida, T. Toriyama","doi":"10.1299/transjsme.20-00045","DOIUrl":"https://doi.org/10.1299/transjsme.20-00045","url":null,"abstract":"A test on the water tightness performance of watertight doors was conducted to obtain knowledge on the fragility beyond design conditions. The performance test was conducted on three types of standard single-swinging watertight doors used for nuclear facilities. Assuming tsunami conditions during an earthquake, the water pressure and the shear strain caused by horizontal force were applied on the watertight door during the test. A shear strain of up to 4000 μ and a water pressure of up to 0.3 MPa were loaded step by step. The water that leaked from the door was measured at each step. The test results showed that the water pressure was related to the leakage quantities, but no clear relationship was observed between the shear strain and leakage quantities. Subsequently, a confirmation test was conducted focusing on the sealed portion of the watertight doors. The condition of the packing and the leakage of the seal during water pressure loading was observed. Consequently, we found that a large quantity of leakage under water pressure was caused by protrusion of the packing, and we inferred that leakage would occur by the same mechanism in actual watertight doors. Using the test results, we considered a method for evaluating the water tightness limit of the door. An analysis on the performance test was conducted using the evaluation method. The result showed that the water pressure that formed a leakage path in the analysis was consistent with the water pressure that caused a large quantity of leakage in the test.","PeriodicalId":341040,"journal":{"name":"Transactions of the JSME (in Japanese)","volume":"123 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129552508","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 : 1900-01-01DOI: 10.1299/transjsme.20-00253
Y. Yamazaki, Kosuke Umemura, Mitsuru Tokai, Marenori Matsuba
{"title":"Influences of manufacturing process parameters on interfacial strength in an additive manufactured ABS-resin/Al-alloy dissimilar joint","authors":"Y. Yamazaki, Kosuke Umemura, Mitsuru Tokai, Marenori Matsuba","doi":"10.1299/transjsme.20-00253","DOIUrl":"https://doi.org/10.1299/transjsme.20-00253","url":null,"abstract":"","PeriodicalId":341040,"journal":{"name":"Transactions of the JSME (in Japanese)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129864361","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 : 1900-01-01DOI: 10.1299/transjsme.18-00469
Taichi Hayashi, Satoki Ogiso, Takanobu Kuroyama
{"title":"Estimation of no-line-of-sight sound source using ratio of peak and root mean square values of cross correlation function","authors":"Taichi Hayashi, Satoki Ogiso, Takanobu Kuroyama","doi":"10.1299/transjsme.18-00469","DOIUrl":"https://doi.org/10.1299/transjsme.18-00469","url":null,"abstract":"","PeriodicalId":341040,"journal":{"name":"Transactions of the JSME (in Japanese)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128743991","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 : 1900-01-01DOI: 10.1299/TRANSJSME.20-00390
T. Yamazaki, Yuji Soda, T. Yamaoka, T. Sasaki
cosα法によるショットピーニング処理したばね鋼表面の残留応力評価 Evaluation of residual stress on shot peened spring steel surface by X-ray cosα method Tomohiro YAMAZAKI*1, Yuji SODA*1, Takuya YAMAOKA*1 and Toshihiko SASAKI*2 *1 Research and Development Center, Mitsubishi Steel MFG. Co., Ltd. 1-6 Yawata, Kaigandori, Ichihara-shi, Chiba 290-0067, Japan *2 Department of Materials Science and Engineering, Kanazawa University Kakuma-machi, Kanazawa-shi, Ishikawa 920-1192, Japan Abstract The purpose of this study is to carry out the basic verification necessary for the correct evaluation of the residual stress of shot peened spring steel by the cosα method. Spring steel (JIS-SUP9) was used as the specimen. Shot peening (SP) was performed on the surface of the specimen by changing the direction and the number of SP. In the X-ray stress measurement, the Debye ring was measured from five directions for each measurement point and used to determine the residual stress. We also examined the effects of changing X-ray incident angles. Residual stress was determined assuming plane stress or tri-axial stress, respectively. As a result, it was found that out-of-plane shear stress (τxz) may occur depending on the direction of SP, and in that case, if stress analysis assuming plane stress is performed, a measurement error will occur. Furthermore, it was found that the smaller the incident angle of X-rays, the larger the measurement error.
{"title":"Evaluation of residual stress on shot peened spring steel surface by X-ray cosα method","authors":"T. Yamazaki, Yuji Soda, T. Yamaoka, T. Sasaki","doi":"10.1299/TRANSJSME.20-00390","DOIUrl":"https://doi.org/10.1299/TRANSJSME.20-00390","url":null,"abstract":"cosα法によるショットピーニング処理したばね鋼表面の残留応力評価 Evaluation of residual stress on shot peened spring steel surface by X-ray cosα method Tomohiro YAMAZAKI*1, Yuji SODA*1, Takuya YAMAOKA*1 and Toshihiko SASAKI*2 *1 Research and Development Center, Mitsubishi Steel MFG. Co., Ltd. 1-6 Yawata, Kaigandori, Ichihara-shi, Chiba 290-0067, Japan *2 Department of Materials Science and Engineering, Kanazawa University Kakuma-machi, Kanazawa-shi, Ishikawa 920-1192, Japan Abstract The purpose of this study is to carry out the basic verification necessary for the correct evaluation of the residual stress of shot peened spring steel by the cosα method. Spring steel (JIS-SUP9) was used as the specimen. Shot peening (SP) was performed on the surface of the specimen by changing the direction and the number of SP. In the X-ray stress measurement, the Debye ring was measured from five directions for each measurement point and used to determine the residual stress. We also examined the effects of changing X-ray incident angles. Residual stress was determined assuming plane stress or tri-axial stress, respectively. As a result, it was found that out-of-plane shear stress (τxz) may occur depending on the direction of SP, and in that case, if stress analysis assuming plane stress is performed, a measurement error will occur. Furthermore, it was found that the smaller the incident angle of X-rays, the larger the measurement error.","PeriodicalId":341040,"journal":{"name":"Transactions of the JSME (in Japanese)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128751881","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 : 1900-01-01DOI: 10.1299/TRANSJSME.20-00428
K. Kizu
Data analysis was conducted to investigate the causes of the difference in creep strength between the heats of Gr. 91 steel. Creep rupture data were divided into multiple regions and fitted with an exponential degradation model. The Larson-Miller constant of each heat obtained by the fitting was used as the objective variable, and chemical concentrations of important elements, hardness and grain size were used as explanatory variables. The stepwise method was used for the data analysis. As a result of the data analysis, it is found that hardness in region H, grain size in region G, and Cr and C concentrations in regions M and L are the causes of the difference in creep strength between the heats.
{"title":"Analysis of the difference in creep strength between heats in Gr. 91 steel by data science","authors":"K. Kizu","doi":"10.1299/TRANSJSME.20-00428","DOIUrl":"https://doi.org/10.1299/TRANSJSME.20-00428","url":null,"abstract":"Data analysis was conducted to investigate the causes of the difference in creep strength between the heats of Gr. 91 steel. Creep rupture data were divided into multiple regions and fitted with an exponential degradation model. The Larson-Miller constant of each heat obtained by the fitting was used as the objective variable, and chemical concentrations of important elements, hardness and grain size were used as explanatory variables. The stepwise method was used for the data analysis. As a result of the data analysis, it is found that hardness in region H, grain size in region G, and Cr and C concentrations in regions M and L are the causes of the difference in creep strength between the heats.","PeriodicalId":341040,"journal":{"name":"Transactions of the JSME (in Japanese)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128806670","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 : 1900-01-01DOI: 10.1299/transjsme.23-00076
Atsushi Kagawa, Yoshihide Suwa
{"title":"MPS陽解法による高粘性ニュートン流体攪拌トルクの数値解析","authors":"Atsushi Kagawa, Yoshihide Suwa","doi":"10.1299/transjsme.23-00076","DOIUrl":"https://doi.org/10.1299/transjsme.23-00076","url":null,"abstract":"","PeriodicalId":341040,"journal":{"name":"Transactions of the JSME (in Japanese)","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128350619","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 : 1900-01-01DOI: 10.1299/transjsme.20-00257
N. Kawagoishi, Yuzo Nakamura, K. Kariya, K. Morino, T. Nagano, K. Yamane
In order to investigate fatigue properties of 18%Ni maraging steel at elevated temperature, rotating bending fatigue tests were conducted for plain and drilled specimens at room temperature (RT) and 673K in air. The specimens involved single-aged ones under an under-aging condition at 753K and double-aged ones in which the second aging was performed at 673K to the single-aged ones. Fatigue strength of the single-aged plain specimens was higher at 673K than at RT, though the static strength was inversely decreased at the elevated temperature. On the other hand, the single-aged drilled specimens exhibited nearly the same fatigue strength at both temperatures. It was found that hardness measured at RT increased with time in the single-aged plain specimens fatigued at 673K, which also appeared in the static aging at 673K. This hardness increase was considered to be attributed to precipitation hardening which might occur due to the existence of excess Mo solute atoms. On the other hand, crack observations revealed that crack initiation in the plain specimens was retarded markedly at 673K in comparison with that at RT, whereas crack propagation rate did not differ significantly between these temperatures and between the plain and drilled specimens. The marked delay of crack initiation in the plain specimens at 673K arose from the oxidation of their surfaces. It was also observed that the double-aging led to a large increase in fatigue strength at RT, but resulted in a slight increase at 673K. Based on these results, it was shown that the main reason of the increase in fatigue strength at 673K in the plain specimens was the suppression of crack initiation due to oxidation, while the increase in hardness observed at this temperature played a minor role.
{"title":"Strengthening mechanism in fatigue of maraging steel at elevated temperature","authors":"N. Kawagoishi, Yuzo Nakamura, K. Kariya, K. Morino, T. Nagano, K. Yamane","doi":"10.1299/transjsme.20-00257","DOIUrl":"https://doi.org/10.1299/transjsme.20-00257","url":null,"abstract":"In order to investigate fatigue properties of 18%Ni maraging steel at elevated temperature, rotating bending fatigue tests were conducted for plain and drilled specimens at room temperature (RT) and 673K in air. The specimens involved single-aged ones under an under-aging condition at 753K and double-aged ones in which the second aging was performed at 673K to the single-aged ones. Fatigue strength of the single-aged plain specimens was higher at 673K than at RT, though the static strength was inversely decreased at the elevated temperature. On the other hand, the single-aged drilled specimens exhibited nearly the same fatigue strength at both temperatures. It was found that hardness measured at RT increased with time in the single-aged plain specimens fatigued at 673K, which also appeared in the static aging at 673K. This hardness increase was considered to be attributed to precipitation hardening which might occur due to the existence of excess Mo solute atoms. On the other hand, crack observations revealed that crack initiation in the plain specimens was retarded markedly at 673K in comparison with that at RT, whereas crack propagation rate did not differ significantly between these temperatures and between the plain and drilled specimens. The marked delay of crack initiation in the plain specimens at 673K arose from the oxidation of their surfaces. It was also observed that the double-aging led to a large increase in fatigue strength at RT, but resulted in a slight increase at 673K. Based on these results, it was shown that the main reason of the increase in fatigue strength at 673K in the plain specimens was the suppression of crack initiation due to oxidation, while the increase in hardness observed at this temperature played a minor role.","PeriodicalId":341040,"journal":{"name":"Transactions of the JSME (in Japanese)","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128369169","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 : 1900-01-01DOI: 10.1299/transjsme.20-00155
T. Harada, Yuto Nakamura
A novel structural synthesis of a mechanism based on the multibody kinematics is proposed in this paper. Instead of the degree-of-freedom analysis by the Grübler’s equation, numbers of the generalized coordinates and those of the constraint equations are introduced for the number synthesis of the mechanism. Sufficient and independent constraints which satisfy the number synthesis are described for the structural synthesis. The Jacobian matrix is derived by the derivative of the constraint equations with respect to time. By using the generalized coordinates, the proposed synthesis is widely applied for the lower degree analysis such as the three-dof planar mechanism, as well as the six-dof spatial mechanism without modifying the primary calculation method of the multibody kinematics. The lower degree analysis removes the redundant coordinates and over-constrained conditions, thus improves the complicated calculation, such as analyzing the planar mechanism using six-dof full spatial analysis. The proposed method is applied to the synthesis of the two-dof differential screw mechanism. The differential screw is comprised of two screw-nut mechanisms, each of them has two mechanical elements. The differential screw mechanisms are divided into two types; The coaxial serial-type differential screw mechanism in which one of the end of each non-driven mechanical element is directory connected to each other, and the parallel-type in which the non-driven mechanical element is connected via mechanical pairs. The rotational pair and the sliding pair are treated as the zero lead and the infinity lead of the screw pair as well as the general helix screw pair. A total of eight generalized coordinates, six kinematic constraints and two driving constraints are set for the number analysis. By evaluating the singularity of the Jacobian matrix from the generalized input velocity and that of the output element, forty combinations of the parallel-type differential screw mechanisms and twenty-four combinations of the serial-type are derived.
{"title":"Structural synthesis of two-dof differential screw mechanism by the multi-body kinematics","authors":"T. Harada, Yuto Nakamura","doi":"10.1299/transjsme.20-00155","DOIUrl":"https://doi.org/10.1299/transjsme.20-00155","url":null,"abstract":"A novel structural synthesis of a mechanism based on the multibody kinematics is proposed in this paper. Instead of the degree-of-freedom analysis by the Grübler’s equation, numbers of the generalized coordinates and those of the constraint equations are introduced for the number synthesis of the mechanism. Sufficient and independent constraints which satisfy the number synthesis are described for the structural synthesis. The Jacobian matrix is derived by the derivative of the constraint equations with respect to time. By using the generalized coordinates, the proposed synthesis is widely applied for the lower degree analysis such as the three-dof planar mechanism, as well as the six-dof spatial mechanism without modifying the primary calculation method of the multibody kinematics. The lower degree analysis removes the redundant coordinates and over-constrained conditions, thus improves the complicated calculation, such as analyzing the planar mechanism using six-dof full spatial analysis. The proposed method is applied to the synthesis of the two-dof differential screw mechanism. The differential screw is comprised of two screw-nut mechanisms, each of them has two mechanical elements. The differential screw mechanisms are divided into two types; The coaxial serial-type differential screw mechanism in which one of the end of each non-driven mechanical element is directory connected to each other, and the parallel-type in which the non-driven mechanical element is connected via mechanical pairs. The rotational pair and the sliding pair are treated as the zero lead and the infinity lead of the screw pair as well as the general helix screw pair. A total of eight generalized coordinates, six kinematic constraints and two driving constraints are set for the number analysis. By evaluating the singularity of the Jacobian matrix from the generalized input velocity and that of the output element, forty combinations of the parallel-type differential screw mechanisms and twenty-four combinations of the serial-type are derived.","PeriodicalId":341040,"journal":{"name":"Transactions of the JSME (in Japanese)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128663522","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 : 1900-01-01DOI: 10.1299/TRANSJSME.18-00336
S. Kawamura, K. Nomura, T. Ise, M. Matsubara
At present, there are many types of isolation system, and many of them are designed for the short-period ground motion. The long-period ground motion has recently attracted the attention, though the isolation system for the short-period ground motion does not have an ability to suppress the vibration due to the long-period ground motion because the frequency of the long-period ground motion is near the natural frequency of the isolation system. In this study, a new isolation system is proposed for not only the short-period ground motion but also the long-period one. The basic concept is that the dynamic property, which is the natural frequency, is changed by adding a spring when the amplitude of isolation table exceeds a threshold value. The validity of the method is checked by the numerical simulation using a single-degree-of-freedom system against the sine sweep ground motion and the actual earthquake ground motion. As a result, it is shown that the resonance can be suppressed by the proposed method. Then the applicability is checked by using the experimental setup. In the experiment, the additional spring is connected with the isolation table by using the clamping mechanism. The adequate clearance between the isolation table and the additional spring is determined in advance. As a result, the system can suppress the resonance phenomenon, so that it was concluded that the proposed system has a sufficient ability to suppress the resonance due to the long-period ground motion.
{"title":"Proposition of isolation system applicable to the long-period earthquake ground motion (Method of changing natural frequency of isolation system with additional spring)","authors":"S. Kawamura, K. Nomura, T. Ise, M. Matsubara","doi":"10.1299/TRANSJSME.18-00336","DOIUrl":"https://doi.org/10.1299/TRANSJSME.18-00336","url":null,"abstract":"At present, there are many types of isolation system, and many of them are designed for the short-period ground motion. The long-period ground motion has recently attracted the attention, though the isolation system for the short-period ground motion does not have an ability to suppress the vibration due to the long-period ground motion because the frequency of the long-period ground motion is near the natural frequency of the isolation system. In this study, a new isolation system is proposed for not only the short-period ground motion but also the long-period one. The basic concept is that the dynamic property, which is the natural frequency, is changed by adding a spring when the amplitude of isolation table exceeds a threshold value. The validity of the method is checked by the numerical simulation using a single-degree-of-freedom system against the sine sweep ground motion and the actual earthquake ground motion. As a result, it is shown that the resonance can be suppressed by the proposed method. Then the applicability is checked by using the experimental setup. In the experiment, the additional spring is connected with the isolation table by using the clamping mechanism. The adequate clearance between the isolation table and the additional spring is determined in advance. As a result, the system can suppress the resonance phenomenon, so that it was concluded that the proposed system has a sufficient ability to suppress the resonance due to the long-period ground motion.","PeriodicalId":341040,"journal":{"name":"Transactions of the JSME (in Japanese)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129004083","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：