Bioactive ceramics, β-tricalcium phosphate (β-TCP), particles reinforced bioabsorbable plastics poly-L lactide (PLLA) composites have been expected to apply for the fracture fixations which have more biocompatibility than monolithic PLLA. In this study, β-TCP/PLLA composites containing three different β-TCP contents (4.8, 9.5, 14.3wt%) were prepared by injection molding. The results of bending tests show bending strength decreases with increasing β-TCP contents. On the other hand, bending modulus increases with increasing β-TCP contents. After immersion tests in PBS at 37°C up to 8 weeks, the mechanical properties were hardly degraded in all specimens. The results of fracture surface observation by scanning electron microscopy indicated that microscopic damage such as debonding between β-TCP and PLLA initiates at β-TCP agglomeration and grows with increasing loading. Analytical predictions of the relationship between stress and strain based on micromechanics considering the progress of debonding between β-TCP and PLLA were in good agreement with experimental results.
{"title":"Experimental and Analytical Characterization of β-Tricalcium Phosphate Particle Reinforced Poly-L-Lactide Composites","authors":"Satoshi Kobayashi, Kazuki Sakamoto","doi":"10.1299/JSMEA.49.314","DOIUrl":"https://doi.org/10.1299/JSMEA.49.314","url":null,"abstract":"Bioactive ceramics, β-tricalcium phosphate (β-TCP), particles reinforced bioabsorbable plastics poly-L lactide (PLLA) composites have been expected to apply for the fracture fixations which have more biocompatibility than monolithic PLLA. In this study, β-TCP/PLLA composites containing three different β-TCP contents (4.8, 9.5, 14.3wt%) were prepared by injection molding. The results of bending tests show bending strength decreases with increasing β-TCP contents. On the other hand, bending modulus increases with increasing β-TCP contents. After immersion tests in PBS at 37°C up to 8 weeks, the mechanical properties were hardly degraded in all specimens. The results of fracture surface observation by scanning electron microscopy indicated that microscopic damage such as debonding between β-TCP and PLLA initiates at β-TCP agglomeration and grows with increasing loading. Analytical predictions of the relationship between stress and strain based on micromechanics considering the progress of debonding between β-TCP and PLLA were in good agreement with experimental results.","PeriodicalId":170519,"journal":{"name":"Jsme International Journal Series A-solid Mechanics and Material Engineering","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125989001","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}
T. Tsujikami, T. Horikawa, Satoru Hirosawa, M. Zako
The inclusion element method with a simple grid model has been proposed as one of the analytical techniques of the mechanical behavior of textile composites, and the effectiveness of this method has been verified. The inclusion element method is applicable to the analysis of all types of textile composites because the element stiffness obtained by the inclusion method through cooperation with a fabric structure simulator is used. From the result of the analysis by the inclusion element method, it has been confirmed that the peculiar crimp-interchange of woven composites occurs and high tensile stress arises at the elements with fiber bundles oriented in the load direction. A comparison between the analyses using a real model and the inclusion element model has shown relatively good agreement. Although the analytical result is greatly dependent on the grid pattern, the inclusion element method can provide a sufficient accuracy of results even when the number of elements in the model is lower than that in the real model.
{"title":"Approach to Analysis of Mechanical Behavior of Textile Composites by Inclusion Element Method","authors":"T. Tsujikami, T. Horikawa, Satoru Hirosawa, M. Zako","doi":"10.1299/JSMEA.49.418","DOIUrl":"https://doi.org/10.1299/JSMEA.49.418","url":null,"abstract":"The inclusion element method with a simple grid model has been proposed as one of the analytical techniques of the mechanical behavior of textile composites, and the effectiveness of this method has been verified. The inclusion element method is applicable to the analysis of all types of textile composites because the element stiffness obtained by the inclusion method through cooperation with a fabric structure simulator is used. From the result of the analysis by the inclusion element method, it has been confirmed that the peculiar crimp-interchange of woven composites occurs and high tensile stress arises at the elements with fiber bundles oriented in the load direction. A comparison between the analyses using a real model and the inclusion element model has shown relatively good agreement. Although the analytical result is greatly dependent on the grid pattern, the inclusion element method can provide a sufficient accuracy of results even when the number of elements in the model is lower than that in the real model.","PeriodicalId":170519,"journal":{"name":"Jsme International Journal Series A-solid Mechanics and Material Engineering","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125049324","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}
This report reveals gigacycle fatigue properties for a modified-ausformed V-added steel with the chemical composition of 0.3C-0.3Si-1.0Cr-0.7Mo-0.3V in mass %. Modified-ausformed and oil-quenched steels were prepared for fatigue tests, followed by tempering at 400°C and 600°C. The tensile strengths of the 600°C tempered steels were almost equal to those of the 400°C tempered versions because of secondary hardening due to fine precipitation of vanadium carbides. The fatigue properties of the 600°C tempered version of oil-quenched steel (QT600) showed little difference from the 400°C tempered version (QT400) in spite of the fine precipitation of vanadium carbides. The modified-ausformed steels (AF400 and AF600) revealed higher fatigue limits at 5× 109 cycles than the oil-quenched versions (QT400 and QT600), although the difference between AF400 and AF600 was small. The remarkable difference between AF400 and AF600 was fatigue strengths at around 106 cycles, i.e. the fatigue strength of AF600 at those cycles was higher than that of AF400. Based on the above results, the effect of the fine precipitation of vanadium carbides was small on the gigacycle fatigue properties, while modified-ausforming could improve those properties. On the other hand, the multiple effects of the fine precipitation and modified-ausforming was large on the fatigue strength at around 106 cycles.
{"title":"Gigacycle Fatigue Properties of V-Added Steel with an Application of Modified Ausforming","authors":"H. Hirukawa, Y. Furuya, S. Matsuoka","doi":"10.1299/JSMEA.49.337","DOIUrl":"https://doi.org/10.1299/JSMEA.49.337","url":null,"abstract":"This report reveals gigacycle fatigue properties for a modified-ausformed V-added steel with the chemical composition of 0.3C-0.3Si-1.0Cr-0.7Mo-0.3V in mass %. Modified-ausformed and oil-quenched steels were prepared for fatigue tests, followed by tempering at 400°C and 600°C. The tensile strengths of the 600°C tempered steels were almost equal to those of the 400°C tempered versions because of secondary hardening due to fine precipitation of vanadium carbides. The fatigue properties of the 600°C tempered version of oil-quenched steel (QT600) showed little difference from the 400°C tempered version (QT400) in spite of the fine precipitation of vanadium carbides. The modified-ausformed steels (AF400 and AF600) revealed higher fatigue limits at 5× 109 cycles than the oil-quenched versions (QT400 and QT600), although the difference between AF400 and AF600 was small. The remarkable difference between AF400 and AF600 was fatigue strengths at around 106 cycles, i.e. the fatigue strength of AF600 at those cycles was higher than that of AF400. Based on the above results, the effect of the fine precipitation of vanadium carbides was small on the gigacycle fatigue properties, while modified-ausforming could improve those properties. On the other hand, the multiple effects of the fine precipitation and modified-ausforming was large on the fatigue strength at around 106 cycles.","PeriodicalId":170519,"journal":{"name":"Jsme International Journal Series A-solid Mechanics and Material Engineering","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124339704","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}
H. Watanabe, Satoshi Kobayashi, M. Fukushima, S. Wakayama
SiC ceramics are expected as oxidation resistant coating material for Carbon/Carbon (C/C) composites. In the present study, SiC ceramics were synthesized through Sol-Gel method with low environmental impact. The gels were synthesized from ethylalcohol, methyltriethoxysilane (MTES), hydrochloric acid (HCl) and purified water (H2O), and it was pyrolyzed at 1 000, 1 500 and 1 700◦C. The structures of gels after heat treatment were analyzed by X-ray diffraction (XRD). XRD results indicated that β-SiC were obtained in the present method and crystallization was increased with increasing heat treatment temperature. There was little weight change in synthesized SiC obtained at 1 000◦C in air, which results in lower weight changes in SiC coated C/C composites comparing with bare C/C composites. However, SiC coated C/C composites were also oxidized because of the generation of cracks during heat treatment at 1 000◦C. Residual tensile strength of SiC coated C/C composites were also higher than that of bare C/C composites after 5 minutes oxidation.
{"title":"Synthesis and Characterization of SiC Ceramics for High Temperature Resistant Coatings and Matrix","authors":"H. Watanabe, Satoshi Kobayashi, M. Fukushima, S. Wakayama","doi":"10.1299/JSMEA.49.237","DOIUrl":"https://doi.org/10.1299/JSMEA.49.237","url":null,"abstract":"SiC ceramics are expected as oxidation resistant coating material for Carbon/Carbon (C/C) composites. In the present study, SiC ceramics were synthesized through Sol-Gel method with low environmental impact. The gels were synthesized from ethylalcohol, methyltriethoxysilane (MTES), hydrochloric acid (HCl) and purified water (H2O), and it was pyrolyzed at 1 000, 1 500 and 1 700◦C. The structures of gels after heat treatment were analyzed by X-ray diffraction (XRD). XRD results indicated that β-SiC were obtained in the present method and crystallization was increased with increasing heat treatment temperature. There was little weight change in synthesized SiC obtained at 1 000◦C in air, which results in lower weight changes in SiC coated C/C composites comparing with bare C/C composites. However, SiC coated C/C composites were also oxidized because of the generation of cracks during heat treatment at 1 000◦C. Residual tensile strength of SiC coated C/C composites were also higher than that of bare C/C composites after 5 minutes oxidation.","PeriodicalId":170519,"journal":{"name":"Jsme International Journal Series A-solid Mechanics and Material Engineering","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115120311","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}
This paper describes the results of our numerical and experimental studies of the nonlinear bending behavior due to domain wall motion in functionally graded piezoelectric actuator under alternating current electric fields. A nonlinear three-dimensional finite element method is employed to simulate the dynamic response of cantilever functionally graded piezoelectric actuator. A phenomenological model of domain wall motion is used in computation, and the effects of ac electric field amplitude and frequency, number of layers, and property gradation on the deflection and internal stresses of the functionally graded bimorphs are examined. It is shown that the predicted deflection results, obtained from the numerical model, agree well with the corresponding experimental results.
{"title":"Nonlinear Dynamic Bending and Domain Wall Motion in Functionally Graded Piezoelectric Actuators under AC Electric Fields: Simulation and Experiment","authors":"Y. Shindo, F. Narita, M. Mikami, Fumitoshi Saito","doi":"10.1299/JSMEA.49.188","DOIUrl":"https://doi.org/10.1299/JSMEA.49.188","url":null,"abstract":"This paper describes the results of our numerical and experimental studies of the nonlinear bending behavior due to domain wall motion in functionally graded piezoelectric actuator under alternating current electric fields. A nonlinear three-dimensional finite element method is employed to simulate the dynamic response of cantilever functionally graded piezoelectric actuator. A phenomenological model of domain wall motion is used in computation, and the effects of ac electric field amplitude and frequency, number of layers, and property gradation on the deflection and internal stresses of the functionally graded bimorphs are examined. It is shown that the predicted deflection results, obtained from the numerical model, agree well with the corresponding experimental results.","PeriodicalId":170519,"journal":{"name":"Jsme International Journal Series A-solid Mechanics and Material Engineering","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132528274","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 objectives of this study are to introduce the use of a photodiode camera for measuring surface strain on soft tissue and to present some representative responses of the tendon. Tendon specimens were obtained from the hindlimbs of canines and frozen to -70°C. After thawing, specimens were mounted in the immersion bath at a room temperature (22°C), preloaded to 0.13N and then subjected to 3% of the initial length at a strain rate of 2%/sec. In tendons which were tested in two blocks of seven repeated extensions to 3% strain with a 120 seconds wait period between, the surface strains were measured with a photodiode camera and near the gripped ends generally were greater than the surface strains in the middle segment of the tendon specimens. The recovery for peak load after the rest period was consistent but the changes in patterns of surface strains after the rest period were not consistent. The advantages of a photodiode measurement of surface strains include the followings: 1) it is a noncontacting method which eliminates errors and distortions caused by clip gauges or mechanical/electronic transducers; 2) it is more accurate than previous noncontact methods, e.g. the VDA and the high speed photographic method; 3) it is a fully automatic, thus reducing labor for replaying video tapes or films and potential errors from human judgement which can occur during digitizing data from photographs. Because the photodiode camera, employs a solid state photodiode array to sense black and white images, scan targets (black image) on the surface of the tendon specimen and back lighting system (white image), and stored automatically image data for surface strains of the tendon specimen on the computer during cyclic extensions.
{"title":"Photodiode Camera Measurement of Surface Strains on Tendons during Multiple Cyclic Tests","authors":"K. Chun, R. Hubbard","doi":"10.1299/JSMEA.49.282","DOIUrl":"https://doi.org/10.1299/JSMEA.49.282","url":null,"abstract":"The objectives of this study are to introduce the use of a photodiode camera for measuring surface strain on soft tissue and to present some representative responses of the tendon. Tendon specimens were obtained from the hindlimbs of canines and frozen to -70°C. After thawing, specimens were mounted in the immersion bath at a room temperature (22°C), preloaded to 0.13N and then subjected to 3% of the initial length at a strain rate of 2%/sec. In tendons which were tested in two blocks of seven repeated extensions to 3% strain with a 120 seconds wait period between, the surface strains were measured with a photodiode camera and near the gripped ends generally were greater than the surface strains in the middle segment of the tendon specimens. The recovery for peak load after the rest period was consistent but the changes in patterns of surface strains after the rest period were not consistent. The advantages of a photodiode measurement of surface strains include the followings: 1) it is a noncontacting method which eliminates errors and distortions caused by clip gauges or mechanical/electronic transducers; 2) it is more accurate than previous noncontact methods, e.g. the VDA and the high speed photographic method; 3) it is a fully automatic, thus reducing labor for replaying video tapes or films and potential errors from human judgement which can occur during digitizing data from photographs. Because the photodiode camera, employs a solid state photodiode array to sense black and white images, scan targets (black image) on the surface of the tendon specimen and back lighting system (white image), and stored automatically image data for surface strains of the tendon specimen on the computer during cyclic extensions.","PeriodicalId":170519,"journal":{"name":"Jsme International Journal Series A-solid Mechanics and Material Engineering","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132144145","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}
Y. Uetsuji, Toshihiro Yoshida, T. Yamakawa, K. Tsuchiya, S. Ueda, E. Nakamachi
Macroscopic ferroelectric properties of piezoelectric polycrystals are strongly affected by microscopic inhomogeneous crystal structure. In our previous study, a multi-scale finite element method based on crystallographic homogenization method has been developed to estimate macroscopic properties considering microscopic crystal morphology. In this paper, the crystal orientation distribution of polycrystalline barium titanate has been measured by SEM·EBSD technique, and the measured crystal orientation distribution has been introduced to the microscopic finite element model. As the prediction of macroscopic properties depends on the sampling conditions of the measured crystal orientations, the effects of number of sampling points and sampling area have been investigated. As a result, the effective sampling conditions have been clarified to estimate macroscopic ferroelectric properties.
{"title":"Evaluation of Ferroelectric Properties of Piezoelectric Ceramics Based on Crystallographic Homogenization Method and Crystal Orientation Analysis by SEM·EBSD Technique","authors":"Y. Uetsuji, Toshihiro Yoshida, T. Yamakawa, K. Tsuchiya, S. Ueda, E. Nakamachi","doi":"10.1299/JSMEA.49.209","DOIUrl":"https://doi.org/10.1299/JSMEA.49.209","url":null,"abstract":"Macroscopic ferroelectric properties of piezoelectric polycrystals are strongly affected by microscopic inhomogeneous crystal structure. In our previous study, a multi-scale finite element method based on crystallographic homogenization method has been developed to estimate macroscopic properties considering microscopic crystal morphology. In this paper, the crystal orientation distribution of polycrystalline barium titanate has been measured by SEM·EBSD technique, and the measured crystal orientation distribution has been introduced to the microscopic finite element model. As the prediction of macroscopic properties depends on the sampling conditions of the measured crystal orientations, the effects of number of sampling points and sampling area have been investigated. As a result, the effective sampling conditions have been clarified to estimate macroscopic ferroelectric properties.","PeriodicalId":170519,"journal":{"name":"Jsme International Journal Series A-solid Mechanics and Material Engineering","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115454643","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}
K. Tsuchiya, T. Kitagawa, Y. Uetsuji, E. Nakamachi
PZT piezoelectric thin films can be promising candidates for microactuators or microsensors in MEMS (Micro Electro Mechanical Systems) or NEMS (Nano Electro Mechanical Systems) because of the quick response. In this research, the RF magnetron sputtering method is used for PZT thin films deposition. The sputtering conditions to control the crystalline plane (111) of perovskite structure for PZT to influence the piezoelectric constant can be proposed. Those sputtering conditions such as substrate angle and temperature, Ar/O2 pressure and flow rate were investigated by the heuristic and experimental design method to fabricate optimum PZT perovskite crystal thin film. The condition of substrate temperature was the most important factor to improve piezoelectric constant. The crystalline structure, surface topography and piezoelectric constant of the deposited PZT were observed by X-ray diffraction structural analysis, atomic force microscope and piezoelectric constant evaluation equipment. PZT thin films with only perovskite structure were obtained. PZT (111) was grown with the increase in substrate temperature, and the piezoelectric property was improved. The elastic modulus of 70GPa for the deposited PZT found a good agreement with the quoted value for commercial based bulk PZT. We obtained a piezoelectric constant d31=-28pm/V and a high performance of bimorph actuator.
{"title":"Fabrication of Smart Material PZT Thin Films by RF Magnetron Sputtering Method in Micro Actuators","authors":"K. Tsuchiya, T. Kitagawa, Y. Uetsuji, E. Nakamachi","doi":"10.1299/JSMEA.49.201","DOIUrl":"https://doi.org/10.1299/JSMEA.49.201","url":null,"abstract":"PZT piezoelectric thin films can be promising candidates for microactuators or microsensors in MEMS (Micro Electro Mechanical Systems) or NEMS (Nano Electro Mechanical Systems) because of the quick response. In this research, the RF magnetron sputtering method is used for PZT thin films deposition. The sputtering conditions to control the crystalline plane (111) of perovskite structure for PZT to influence the piezoelectric constant can be proposed. Those sputtering conditions such as substrate angle and temperature, Ar/O2 pressure and flow rate were investigated by the heuristic and experimental design method to fabricate optimum PZT perovskite crystal thin film. The condition of substrate temperature was the most important factor to improve piezoelectric constant. The crystalline structure, surface topography and piezoelectric constant of the deposited PZT were observed by X-ray diffraction structural analysis, atomic force microscope and piezoelectric constant evaluation equipment. PZT thin films with only perovskite structure were obtained. PZT (111) was grown with the increase in substrate temperature, and the piezoelectric property was improved. The elastic modulus of 70GPa for the deposited PZT found a good agreement with the quoted value for commercial based bulk PZT. We obtained a piezoelectric constant d31=-28pm/V and a high performance of bimorph actuator.","PeriodicalId":170519,"journal":{"name":"Jsme International Journal Series A-solid Mechanics and Material Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131070345","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 this paper a new theoretical method is proposed for calculating the normalized contact duration and indentation depth in elastic, elastic-plastic and plastic collision of circular plates. The contact duration is composed of total loading time and unloading time that are dependent on the relationship between the interaction force and normal indentation. For plastic collision, the contact duration relates to the coe ffi cient of restitution (COR) of the collision. Considering the actual thickness of a circular plate, a coe ffi cient of indentation (COI) is newly introduced in theoretical analyses of the COR. According to experimental results of COR, a hybrid nonlinear model is also proposed to describe the COR of circular plates for obtaining the unloading time of the plastic collision. Contact force history during collision can be expressed approximately by a half-sine wave and the force and contact duration is calculated numerically.
{"title":"Theoretical Investigation on the Contact Duration in Elastic and Inelastic Collision of a Circular Plate to a Planar Surface","authors":"Zhong-Lan Lu, Koichi Tanaka, M. Nishida, F. Huang","doi":"10.1299/JSMEA.49.258","DOIUrl":"https://doi.org/10.1299/JSMEA.49.258","url":null,"abstract":"In this paper a new theoretical method is proposed for calculating the normalized contact duration and indentation depth in elastic, elastic-plastic and plastic collision of circular plates. The contact duration is composed of total loading time and unloading time that are dependent on the relationship between the interaction force and normal indentation. For plastic collision, the contact duration relates to the coe ffi cient of restitution (COR) of the collision. Considering the actual thickness of a circular plate, a coe ffi cient of indentation (COI) is newly introduced in theoretical analyses of the COR. According to experimental results of COR, a hybrid nonlinear model is also proposed to describe the COR of circular plates for obtaining the unloading time of the plastic collision. Contact force history during collision can be expressed approximately by a half-sine wave and the force and contact duration is calculated numerically.","PeriodicalId":170519,"journal":{"name":"Jsme International Journal Series A-solid Mechanics and Material Engineering","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131571108","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}
K. Mori, Y. Nakagawa, H. Kuroki, Keisuke Nakashima, K. Ikeuchi, T. Mine, Takashi Nakamura, S. Kawai, Takashi Saito
In orthopedic field, various new treatments of articular cartilage defect, for example autogenous osteochondral grafts, have been developed. With the spread of these treatments, orthopedists began to focus on the mechanical properties of recovered articular cartilage. The quantitative evaluation of articular cartilage before and after these treatments gives orthopedists the important information to improve these treatments and develop new treatments. We have been investigating the non-contact ultrasonic evaluation for articular cartilage under arthroscopy. In this paper, it was hypothesized that the ultrasonic evaluation depended on the collagen fiber in cartilage. The enzymatically degradation of collagen fiber in cartilage surface was performed. The effect of the degradation on sound velocity, attenuation coefficient and signal intensity, which is the index of cartilage stiffness calculated from the proposed method, was measured. The numerical analysis was performed to clear the relation between the cartilage character and ultrasonic parameters. Experimental and numerical results suggest that the present method can be expanded the sensitive evaluation for cartilage disease in clinical field.
{"title":"Non-Contact Evaluation for Articular Cartilage Using Ultrasound","authors":"K. Mori, Y. Nakagawa, H. Kuroki, Keisuke Nakashima, K. Ikeuchi, T. Mine, Takashi Nakamura, S. Kawai, Takashi Saito","doi":"10.1299/JSMEA.49.242","DOIUrl":"https://doi.org/10.1299/JSMEA.49.242","url":null,"abstract":"In orthopedic field, various new treatments of articular cartilage defect, for example autogenous osteochondral grafts, have been developed. With the spread of these treatments, orthopedists began to focus on the mechanical properties of recovered articular cartilage. The quantitative evaluation of articular cartilage before and after these treatments gives orthopedists the important information to improve these treatments and develop new treatments. We have been investigating the non-contact ultrasonic evaluation for articular cartilage under arthroscopy. In this paper, it was hypothesized that the ultrasonic evaluation depended on the collagen fiber in cartilage. The enzymatically degradation of collagen fiber in cartilage surface was performed. The effect of the degradation on sound velocity, attenuation coefficient and signal intensity, which is the index of cartilage stiffness calculated from the proposed method, was measured. The numerical analysis was performed to clear the relation between the cartilage character and ultrasonic parameters. Experimental and numerical results suggest that the present method can be expanded the sensitive evaluation for cartilage disease in clinical field.","PeriodicalId":170519,"journal":{"name":"Jsme International Journal Series A-solid Mechanics and Material Engineering","volume":"43 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132501310","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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