Deformation of a carbon fiber in an epoxy matrix was investigated by measuring electrical resistance change of a arbon fiber. First, electrical resistance change of a carbon fiber due to temperature change was measured to eliminate the effect of exothermal reaction of epoxy matrix. Then,electrical resistance change of carbon fiber in an epoxy matrix was measured during the matrix curing. Electrical resistance of the carbon fiber decreased in the early phase of the matrix curing,then increased due to the shrinkage of the epoxy matrix. The effect of low electrical resistance of the epoxy hardener was larger than the effect of temperature change. After the curing of the epoxy matrix, electrical resistance change of the carbon fiber was about 0.2%,from which deformation of the carbon fiber was discussed. The carbon fiber contracted both in longitudinal and radial direction due to shrinkage of the epoxy matrix.

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Direct compression test of a single carbon fiber was performed by originally developed testing machine. The maximum displacement of the testing machine was 200μm with 5nm step and maximum load was 200mN with 0.3mN resolution, Carbon fiber with 5μm diameter was fixed on a base using an epoxy and then cut into 10μm length using a focused ion beam to prevent buckling in the compression test. Measured compressive strength of the carbon fiber was about 3000MPa which was much lower than the tensile strength 5880MPa. Fracture surface of the carbon fiber showed ending fracture which may reduce measured compressive strength. Young's modulus of the carbon fiber was not obtained because of relatively high compliance of the test fixture. The experimental results imply the need for some modification of the test apparatus to correctly measure the compression property of a single carbon fiber.

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Compression test of a single carbon fiber in an epoxy matrix was performed by means of a four point bending test. Compressive behavior of the carbon fiber was observed during the test. Initiation of compressive failure was detected by measuring electric resistance change of the carbon fiber. The electric resistance decreased with increase of compressive stain. Then, the electric resistance increased with onset of the fiber compressive failure. Pure compressive failure was observed without fiber micro-buckling. A compressive strength of the carbon fiber was calculated using a liner constitutive law. Compressive strength of t1!e unidirectional CFRP was also measured. The compressive strength of the carbon fiber in die epoxy matrix and the unidirectional CFRP was discussed from the results.

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This paper examines fiber/matrix interfacial strength and growth behavior of the interfacial debonding with glass fiber and epoxy using a partially embedded single fiber. Test specimen with partially embedded single fiber in the resin is made by using the capillary action of the resin, By observing the cross section of a specimen with an optical microscope, it can be confirmed that the fiber is partially embedded in the resin. Interfacial debonding test is conducted by applying peeling force to the fiber to evaluate interfacial fracture toughness. By using the partially embedded single fiber fracture toughness is calculated from the load-displacement curve and the debonding growth length which is obtained by the experiments.

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A cruciform specimen with multiple fibers is used to evaluate the fiber/matrix interfacial tensile strength. The model composite contains thick fibers for the precise detection of the debonding initiation location. By arranging two fibers the influence of the adjoining fiber on a debonding behavior can be estimated. The fibers are aligned parallel each other and perpendicular to the loading direction. The effect of the interval between two fibers on the debonding behavior is observed. FEM analysis shows that the stress concentration at the inner pole of an interface becomes large as a fiber interval becomes small. However, it is experimentally observed that the debonding initiation occurs at the outer pole. Since this behavior is considered to be due to the cure shrinkage of resin, FE analysis in which thermal expansion is incorporated as chemical shrinkage is conducted. As a result of the analysis, it is explained that debonding initiates at the interface angle of 90°.

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Effect of filler content on higher-order structure of poly(L-lactic acid)(PLLA)β-tricalcium phosphate/poly(L-Lactic Acid) composites (β-TCP/PLLA) after immersion in a phosphate-buffered solution at 37℃ was investigated by differential scanning calorimetry. It is found that β-TCP/PLLA composite has higher initial crystallinity and lower crystallization temperature than neat PLLA. The crystallinity of PLLA and 15wt% composites increased monotonically by immersion in PBS. Conversely, the crystallinity of 30wt% composites increased and decreased after 16 weeks. From the experimental results, it has been suggested that PLLA was hydrolyzed and crystallized simultaneously, then selective hydrolysis of amorphous regions and growth of crystallites into the larger crystalline or crystallographic transformation occurred.

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In the present study, in order to improve interfacial strength between Poly lactic acid (PLA) and β-tricalcium phosphate (p-TCP) in β-TCP/PLA particles dispersed bioabsorbable composites, effects of a weight-average molecular weight of PLA On the mechanical properties of β-TCP/PLA particles dispersed bioabsorbable composites were investigated by using two poly lactic acids with different weight-average molecular weight. In the result, when weight-average molecular weight of PLA changed mechanical properties of β-TCP/PLA particles dispersed bioabsorbable composites also changed. A purpose of this study is clarifying the mechanism of stress transferring in an interphase in order to prevent destruction due to interfacial debonding.

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Green composite(GC) has been attracted as an alternative material of glass fiber reinforced plastics (GFRP). In this study, mechanical properties of green composite using carbonized jute fiber (CJGC) was investigated. Before molding, carbonization was conducted to the jute fiber. Carbonization temperatures were 300℃ and 400℃. Heating rates were 2℃/min and 60℃ /min. Holding times were 3hrs and 6hrs. CJGC was fabricated by using carbonized jute fiber and polylactic acid (PLA). Static tensile test of CJGC was conducted. As a result, the tensile modulus of CJGC was improved by heating rate. Tensile strength of CJGC was improved by carbonization temperature. Therefore these results implied that carbonization temperature and heating rate affect the mechanical properties of CJGC .

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Natural fiber twisted yarn is often used for green composites as a reinforcement. It is generally known in textile engineering that the mechanical properties of twisted yarns are depended on fiber properties (fiber length, fiber diameter), twist angle and so on. However, mechanical properties of the composites using twisted yarns have not been clarified. In this paper, the effect of twist angle on tensile properties of composite was investigated.

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Poly-L-lactide (PLA) is applied in clinical application as substitute material of metallic bone fixation screws, because of PLA is bioabsorbable materials and has high level of biocompatibility. Applications of conventional bioabsorbable bone fixations are limited to low loaded region, because of their lower mechanical characteristics. In this study, PLA screws were prepared by extruding and forging. The prepared extrusion drawing conditions are with or without lubricant and 1 to 8 extrusion ratios. As higher order structure of the screws, crystallinity was measured. As mechanical properties of the screws, torsional strength and shear strength were measured. As a result, the ciystallinity didn't change at extrusion ratios 1 to 8. An increase of the shear strength and decrease of torsion strength were confirmed in drawn screws. And, it was predicted that orientation is restricted by lubricant.

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This study presents a fabrication method of the FRTP using in-situ polymerization polyamide 6 as the matrix in a vacuum assisted resin transfer molding (VARTM) without a large and special equipment One of authors in this paper developed carbon/glass hybrid fibers reinforced thermoplastics (HFRTP) and carbon fiber reinforced thermoplastics (CFRTP) plates by using the polyamide 6. They had no voids and unfilled resin parts because the ε -caprolactam had very low viscosity before polymerization. Furthermore, their FRTP not only exhibited superior mechanical properties, but also was suitable for high-speed molding, namely within one minute process time because it could be released from the mold without a cooling process. The mechanical properties of HFRTP and CFRTP were investigated by three-point bending tests. Moreover, their results were compared with those of HFRP (hybrid fibers reinforced epoxy) and CFRP (carbon fibers reinforced epoxy).

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The styrene-isoprene-styrene (SIS) triblock copolymer nanofibers were fabricated for the dispersed phase of a composite using electrospinning. A mixed solvent of toluene and N, N-dimethylformamide (DMF) was selected and used, and the mixing ratio of toluene/DMF was varied from 100/0 to 50/50. Nanofibers with an average lowest diameter of 350 nm were obtained at the mixing ratio of 50/50. The solution used in the electrospinning was rheologically investigated, which became gel as the amount of DMF increased. This could be attributed to the increase in the interaction between SIS molecules with the increasing amount of DMF that was a poor solvent for SIS. In addition, the electrical conductivity of the solvent remarkably increased as the amount of DMF increased. The slightly stronger interaction between SIS molecules and the high electrical conductivity could contribute to the formation of homogeneous and thin fibers.

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To improve the adhesive strength, we performed surface modification of CFRP using Nanoimprint lithography (NIL) in previous study. However, because it used a metal mold, the manufactured surface was limited to the 2.5 dimension. In addition, it was also problematic that a release agent applied to mold surface remained on the surface of microstructures; thus, the adhesive strength was degraded. In the present study, we propose an imprint process of three-dimensional shape with interlock structure using a solubility mold. We fabricated the soluble mold using negative photoresist by inclined exposure method, and conducted imprint process for CFRP using the soluble mold. As a result, the three dimensional surfaces with interlock were successfully imprinted on the CFRP surface.

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For casting small polymer parts (10 mm cube), with the aim to achieve footprint-saving, simple operation, energy conservation, the realization of a small-desktop injection molding machine. To produce the machine which is an improvement to the new system disk from the conventional method of screw plasticizing process, its performance was evaluated injection. Although it is necessary to improve the method for supplying polymer to the disk, it was confirmed that no air bubbles are mixed, the polymer is extruded by the rotation of the disk. As a result of ejecting polymer, a possibility of realizing a small-desktop disk-type injection molding machine was obtained.

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Moldings have some fault called sink due to these shrinkage. According to previous reports, if the injection pressure and the mold clamping pressure increase, more plastics are injected in mold die. We shall be able to inhibit sink at some points where they grow. In this study, molding is preliminarily given form, such as a flat and a curvature plate. We investigate difference of deformation between flat and curvature areas. We consider how to inhibit sink by results of analysis. Therefore we compere the deformation which is measured with results of simulation and experiments of injection molding.

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This study represents some findings for path interval determination in multi-axis flat end milling. Because of space constraint, this paper only describes the findings related to a planar and convex surface. In tool path generation, path interval determination is usually performed using the formulae derived from the geometrical relationship between a cross-feed distance and scallop height. However, the formulae have not necessarily been provided for the commonly-used cutting tools. Hence, it also seems that there still remains much to be studied on path interval determination in multi-axis flat end milling. For path interval determination, the novel expressions and these solutions were provided with the reference to those geometrical relationships.

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Diamond turning and grinding are the critical processes to produce precise parts such as lenses and molds. In particular, these parts with small in size become increasingly important. Accordingly, ultra-precision machine tool that effectively machines these parts is desirable. Water driven turning system was thus developed for the single point diamond turning for machining micro parts with several millimeters. This machining system consists of the water driven spindle and the water driven stage. The spindle and stage equip water hydrostatic bearings and water driven mechanism. In the present paper, the single point diamond turnings are carried out using the water driven turning system. The experimental results show that the surface roughness of diamond turning is approximate 0.02 μm/Ra. The paper investigates the cause of relatively larger surface roughness in the experiments for achieving improvement of the machining performance of the developed machining system.

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Magnesium alloy is the lightest metal in practical use and it is an effective material to contribute the weight saving for vehicles and other transportation equipment. In this study, to achieve a high strength due to grain refinement of AZ80 magnesium alloy that is used in high strength and low ductility sheet material in AZ series Magnesium alloy, forging and rolling was applied. As a result of examining deformation behavior under the uniaxial and biaxial tension at various temperatures, elongation of the biaxial is decreased compared to those of uniaxial due to deformation restraint at each temperature. Furthermore, the yield stress measured value showed a value close to Hill's 93 yield function at each temperature. In addition, the shape of the yield surface at more than 423 K showed an ellipsoidal shape. But, the shape of the yield surface had a distorted shape at room temperature because anisotropy appeared clearly.

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The objective of this study was to develop new forming methods making use of undesirable phenomena caused by bending for aluminum alloy extruded sections. The deformations of the cross section in channel exist inner falling and outer falling. In this report, we examined the effect of forming jig (guide plate and forming die) on deformation of cross section in press bending with inner falling in channel by a finite element method and an experiment. Then, it was clarified that the height of guide plate and the radius of forming die influence the deformation of the cross section.

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The C-U-O forming method is generally applied when manufacturing large diametrical pipes for petroleum and natural gas pipeline. C-U-O pipes of about 10-time length to the diameter were producted conventionally, the product time per length and the cost should be reducible by making of long pipes. Since length of welding would be reduced, fatigue strength and static strength will be achieved. In this study, characteristic of long pipe forming used C-U-O forming method was investigated by FEM analysis. Effect of each parameters about accuracy of blank was examined, and optimal forming condition for long high aspect pipe was showed by forming experiment.

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This study deals with the simultaneous measurement of the flow and stress of ultraviolet (UV) curable resin illuminated at UV ray. The flow is observed as particle trajectory patterns obtained using a particle tracking velocimetry technique, and stress as isochromatics, principal-stress directions and shear 45° obtained using a photoelastic technique, respectively; The specimens consist of glass plates, acrylic plates and UV curable resin in liquid form with acrylic powder. The specimens are illuminated with UV rays downwards from the upper side of the specimens, and the visual and photoelastic images of the resin in curing process are captured at a constant time interval using a digital and CCD cameras, respectively. Results indicated that the stresses in the resin during the curing, process depended on the degree of contact between the mold and the cured part of the resin and were almost independent on the flow of the uncured resin.

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The residual stress generated in a diffractive grating formed by ultraviolet (UV) curable resin was analyzed using a photoelastic technique. The stress was expressed as isochromatics and principal-stress directions, which are obtained using a four-step phase-shifting technique based on a plane polariscope. The specimens consisted of a steel mold with a diffraction grating pattern, glass plates and UV curing resin in liquid form. The specimens were illuminated with UV rays downwards from the upper side of the specimens, and the photoelastic images of the resin after curing were captured using a digital camera. Results indicated that the residual stress generated in the resin was complex.

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An achromatic quarter-wave plate is used to determine the principal-stress directions from color photoelastic fringes obtained in a semicircular polariscope, which is composed of a plane polariscope with a quarter-wave plate. Four phase-shifted photoelastic fringe images are acquired using the polariscope, and used to obtain the wrapped principal-stress direction using a phase-shifting technique. To investigate the effectiveness of the quarter-wave plate, the principal-stress directions from color photoelastic fringes of a circular disk subjected to a concentrated load are determined. Results show that the quarter-wave plate is effective for determining the principal-stress direction.

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Recently, a new container for liquid of food products, which consists of a case made of a sheet of plastic or paper and a liquid-packing bag with a pouring lip made of a plastic film has been developed. The improvement of the resistance of the new container to drop impact is desired because the resistance is not adequately. To improve the resistance, it is important to investigate the pressure in liquid-packaging bags. In this study, the pressure in liquid-filled plastic film bags with a pouring lip and a heat-sealed area to reinforce the lip subjected to drop impact is measured using a pressure sensor. Results indicated that the heat-sealed area strongly affects the pressure in the bags.

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Recently, a new container for liquid of food products, which consists of a case made of a sheet of recycled paper and a liquid-packaging bag with a pouring lip made of a plastic film has been developed. The improvement of the resistance of the new container to drop impact is desired because the resistance is not adequately. To improve the resistance, it is important to investigate the deformation of the case. In this study, the deformation of the bottom of the case subjected to drop impact was observed using a high speed camera. Results indicated that the case had characteristic deformation.

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In order to verify the validity of measurement by a digital image correlation (DIC) technique, we measured the directions of principal strain using 3-dimensional DIC and reflective photoelastic coating techniques simultaneously and compared these results. For the photoelastic technique, a semicircular polariscope was used to acquire four phase-shifted photoelastic fringe images, and the direction of principal strain was obtained from the images. A specimen used was a circular ring compressed by a diametrical opposite concentrated load. As a result, it turned out that the measurement accuracy of DIC becomes worse when the rate of the specimen size on the images in pixels to the full screen size in pixels was small.

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The movement of a lower jaw dentition subjected to distal loads from anchor screws is investigated using a digital image correlation technique. A sample consists of a lower jaw, teeth, periodontal membranes, a correcting wire, brackets, and anchor screws. A force of 5.88 N is applied to die wire near the brackets bonded on the first and second premolars and the first molar on the left and right sides of the jaw. The direction of the force from the horizontal is set to 0°, 10° and 20°. Results indicate that the movement of the teeth depends on the position and direction of load.

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The strain on the surface of the cephalic horn of Japanese rhinoceros beetles (Trypoxylus dichotomus) is measured using a three-dimensional, digital image correlation (3D-DIC) technique. The measured surfaces of the horn are sprayed with white paint and speckled with black paint on the white paint. The head with the horn is cut from the thorax, and the head is fixed with epoxy resin. A force of 5 N is applied to the distal part of the horn. Images before and after loading are captured, and the strain on the surface of the horn is calculated from the images using a 3D-DIG technique. Results indicated that the horn is considered as a uniform strength beam.

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The reduction of wheels and rails wear is a very important factor in improving running safety and reducing maintenance cost. We conducted an experiment to clarify the mechanism of wear development by using 1/5 scaled rolling stock test stand which composed of wheelset and roller rings. We carried out the experiment under, different curving and friction conditions. In this paper, the influences of changing track curvature and coefficient of friction on wheel wear quantity are discussed. For each boundary condition, it is clarified that wear coefficient does not depend on travel distance. Also it is pointed out that the wear parameter changes extremely at the critical curvature.

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Metal foils indicates low level fracture strain compared with sheet metal. In this study, the free surface roughening is focused on to clarify the mechanism of ductile fracture for metal foils, since the ratio of surface roughness to thickness become larger compared with sheet metal. Materials used are pure copper, pure aluminum and pure titanium with thickness of 0.05, 0.1, 0.3 and 0.5mm respectively. Free surface roughening and ductile fracture behavior are observed under uni-axial tensile state. As a result, the surface roughening to thickness of metal foils with thickness of 0.05, 0.1mm was larger than that of sheet metals with thickness of 0.3, 0.5mm. In addition, an inhomogeneous FE material modeling is proposed for prediction of surface roughening and necking behavior. In this model, grain size and variation in flow stress of each grain as aspect of mesoscopic material information were considered for modeling of material inhomogeneity. The necking behavior of metal foil can be expressed by inhomogeneous FE material modeling. Therefore, it can be concerned that surface roughening to thickness affects the fracture of metal foil.

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This study aims to make clear the effect of directional microstructure on a scaffold on the cell adhesion force. Grooved scaffold was produced by combining lithography and casting of polydimethylsiloxane (PDMS), of which pitch was 6 μm and height 0.6 pm. PC12 cells were cultured and fixed on the scaffold. The cultured cells were peeled-off with an AFM cantilever fixed on a micromanipulator. The adhesion force was quantified by analyzing the deflection of cantilever based on microscopic images captured during peering-off action. The adhesion forced were different depending on the groove direction. The adhesion parallel to the groove was about 800 μN while that perpendicular to the groove was 600 μN.

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In this study,ion irradiation method was used in order to control bioactivity of hydroxyapatite (HA), that is apatite formation on the HA surface. Bioactivity of hydroxyapatite that was irradiated with Ca or Mg ion at different ion dose and depth was investigated by soaking in simulated body fluid (SBF). The HA irradiated with Ca ion at different ion dose and depth showed fibrous apatite formation on the surface after soaking in SBF at all ion irradiation condition. However, apatite formation rate was different. Apatite formation on the HA irradiated with Mg ion became lower with increasing Mg ion dose. Thus, apatite formation of the HA surface can be controled by changing ion species, dose and depth.

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This study describes effects of fish bone structures that Tetraodon Abei (in family Tetraodontidae) and sea bass have under two-dimensional hydrostatic pressure. In order to compression behavior of specimens which are duplicate sections of these fishes, We put hydrostatic test pressure on them through glass beads and measured strains with three axis strain gauges and 2D image correlation method. As a result, if bone area ratio increase, sea bass section's deformation stability improved but magnitudes of principle strain increased. Other hand, Tetraodon's deformation stability improved without increasing magnitude of principle strain. We estimated that fish bone structures of Tetraodon have superior characteristic for deformation stability under hydrostatic pressure.

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With the development of computing technology in recent years, numerical simulation system is developed to calculate the body behavior on a computer. There are some advantages of applying numerical simulation in vehicle development. For example, the cost reduction and safety. But the validity of numerical model needs to be shown. The experiment of human behavior was performed under stationary vibration but it does not cover the body behavior such as the movement caused by the influence of lateral acceleration that can be seen in the driving car. Furthermore, motion of body may be affected Mental Workload (MWL). In this research, we have tested experiment on the relationship between MWL and motion of body.

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Bioactive ceramics/poly-L-lactic acid (PLLA) composites have been expected as a material for bone fracture fixations which have more biocompatibility than monolithic PLLA. In this study, β-tricalcium phosphate (β-TCP)/PLLA composites containing three different β-TCP contents (5, 10, 15 wt%) were prepared by injection molding and in vitro hydrolysis behavior were characterized. These specimens were immersed in phosphate buffered solution, and molecular weight was measured. Molecular weight degradation of composites became faster withβ-TCP content at the same immersion time. To predict hydrolysis behavior of composites more precisely, effect of water diffusion is considered in proposed models. Predictions based on the present models are in good agreement with experimental results and the effectiveness of the models was confirmed.

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By performing a discretization of Landau-Ginzburg model for membranes on triangulated surfaces, we numerically find an expected phase transition of the model. In this model, the bending energy is defined with tangential vectors on the surface, while the simulations performed so far assume a bending energy defined by a normal vector of the surface. We show that a tangential bending energy model can be studied numerically.

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The adhesive and anisotropic properties of cell-derived biomaterials are affected by micro- or nanoscale structures processed on culture surface. In the present study, various nanopriodic structures were patterned on titanium surfaces using femtosecond laser processing by various scanning speeds from 50 to 1,200 mm/min. Then, human synovium-derived mesenchymal stem cells were cultured on the substrates. Results revealed that as the scanning speed became higher, the pitch and depth of grooves became larger and more shallow, respectively, and the surface roughness (R_a,) became lower. In addition, the duration for cell extension was significantly reduced on the processed titanium having wider pitch, more shallow groove, and smoother surface. Moreover, cell orientation was well aligned on the titanium surface processed at a scanning speed of 1,200mm/min.

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The purpose of this study is to develop a new walking assist device. The theory called the Spinal Engine describes that the essence of walking is in a motion of the spinal. In this study, it is assumed that the basic principle of walking is in the lateroflexion and twist of the trunk, and that the walking style combining the bilateral step of the lower limbs with the twist of the trunk is useful for assisted walking. The proposed device adopted parallel linkage mechanisms to assists flexion-extension and abduction-adduction of the hip joint. At the flexion-extension mechanism* one motor can rotate both side links by using bevel gears. The number of motors in this device is three. The result of the walking experiment to evaluate the proposed device, a support was confirmed at only abduction-adduction of the hip joint. It is thought that the cause of this result was control method. In future work, a control method using neural rhythm generators will be adopted as another control method.

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The purpose of this study is to evaluate the normal walking and Nanba walking quantitatively using the forward dynamic walking simulation. The dynamics of the human body was represented by a 26-rigid-link system and muscular models. The neuronal system was represented by two sub-systems: the rhythm generator system consisting of neural oscillators, and the sensory feedback system. Unknown neuronal parameters were adjusted by a numerical search method using the evaluative criterion for locomotion that was defined by a hybrid among the locomotive energy efficiency, the toe clearance and the magnitude of the ground reaction force. Using different feedback coefficients, two walking patterns were generated. Normal walking efficiency was better than Nanba walking. It was considered that despite short stride, Nanba walking is suitable for fast walking speed.

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We present a numerical result of a geometric surface model for anisotropic membranes. In this model, a "tilt" is assumed on the surface. This tilt represents a three-dimensional degrees of freedom of lipid molecules and is an analogue of "the spin variable" in the ferromagnetic models. We see a multitude of anisotropic phases in the model, and find that the reason of this multitude is a dependence of the bending energy and surface tension on the position and the direction of tilts.

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Bioactive ceramics attracts attentions as materials of the bone implant, because of their high biocompatibility. For example, hydroxyapatite (HA) has bone-bonding ability, and β-tricalcium phosphate (P-TCP) has a high bioresorbability in body environment. In this study, HA/β-TCP composites with different content of β-TCP (0,10,20,30wt%) were prepared by wet mixing of HA and β-TCP powder, compaction of the powders and sintering. Pressureless sintering and spark plasma sintering were employed in this study. To improve sinterability of HA/β-TCP composites, the effect of additive of MgO was investigated. It was found that MgO improved sinterability of only P-TCP. Spark plasma sintering improved sinterability compared to pressureless sintering. As a result of X-ray powder diffraction measurement, it was found that MgO inhibited the change of β-TCP structure in case of pressureless sintering, but not in case of spark plasma sintering.

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In this study, we developed a system to evaluate pedaling techniques of cycling. The system analyzes the magnitude and directions of pedaling force. The pedaling force was measured by new designed biaxial load cells which were applied to between pedals and shoes. This load cells were able to measure magnitude and direction of pedaling forces of both pedals, respectively. To evaluate the direction of the pedaling forces, pedal angle was calculated by the link mechanism of lower limbs. The length of the each element of lower limbs, length of crank and position of greater trochanter were supposed to be given as constant parameter for computational calculation. The pedaling forces were converted to forces on coordinate respective to tangential and radial directions of each crank. Evaluation method of pedaling techniques was proposed by the force decomposed

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AE monitoring of damage process of rabbit patellar tendon under static tensile load was carried out. Considering strong viscoelasticity of tendon, load was applied at various loading rate (10, 1, 0.1 mm/min) until the complete rupture in physiological saline at 37°C. The displacement of the specimen was monitored by a digital video camera, and acquired images were used for determining the displacement distribution in tendon by the digital image correlation (DIC) technique. It was found that the average failure stress increased as loading rate increased, and the differences in maximum stress were considered to be statistically significant. AE signals were detected before the maximum load and AE source locations corresponded to the locally elongated area, which indicates that fascicle failure takes place before the maximum load. Consequently, the fundamental insights for the damage monitoring technique which are indispensable for the optimization of programs of sports training or rehabilitation are obtained.

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The purpose of this the present study was to measure the in-situ forces in knee ligaments and other soft tissues during knee hyperextension, for the assessment of their mechanical functions. Human fresh cadaveric knee specimens (n=5) were subjected to two types of hyperextension test; a simple hyperextension test, and a combined hyperextension test with proximal force application. In addition, the knee joints with the oblique popliteal ligament (OPL) transected were also subjected to the simple hyperextension test. The 6-DOF motion of, and force/moment applied to the intact knees were recorded during the tests. And, then, the 6-DOF intact knee motion was reproduced after a sequential transection of the ligaments and soft tissues to determine in-situ forces. In response to 10 Nm of extension moment (simple hyperextension test), the OPL force was slightly higher than those in other structures. In-situ forces in the structures remained almost unchanged in response to 10 Nm of extension moment combined with 30 N of proximal force. In the OPL-transected knees, in-situ forces in other structures were slightly increased although no significant deference was observed. These results suggested that the risk of damage to the OPL is higher than other structures in response to hyperextension. It is also suggested that the risk of secondary damage to other structures such as MCL, POL, Capsule, and PCL is increased after the transection of the OPL.

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The purpose of this study is to investigate the dynamic characteristics of hand-arm system, and to investigate an experimental method for evaluating the hand-arm system. The behavior of the hand-arm system is measured by a motion capture system while the vibration is transmitted to the subject through the grip. The input frequency range is 1-50 Hz, and the variation of wave form has four case; random waves of three different amplitudes, and a sinusoidal sweep. The FRFs of hand-arm system are estimated, and modal parameters are identified by Multi-reference Iterative Curve Fit. In the result, we obtain the mode shapes and the dependency of natural frequency on the input level is observed in case of random excitation.

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A medical corset (lumbar brace) is used to reduce the burden on the waist by increasing the abdominal pressure. The purpose of this study was to quantitatively evaluate the differences in three types of corsets, and to clarify mechanical relationship between the configuration and effect of corsets. In the experiment, nine subjects wore the corsets, and the electromyogram (EMG), contact pressure, and slippage between the corset and the trunk were collected by motion capture systems. It was discussed that mechanical properties such as stiffness and size of the corset influenced on the muscle load and fitting of the corset.

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