Yutaka Sawaki

Dynamic Tensile Behavior of Aramid FRP Using Split Hopkinson Bar Method

It is well known that fiber reinforced composite materials are new industrial materials replaced with metal, wood or concrete, etc. and are equipped with high intensity and high elasticity. An aramid fiber has relatively high impact intensity compared with carbon fiber or glass fiber. When an aramid fiber was made into a composite material (Aramid Fiber Reinforced Plastic: AFRP), it has the feature which shows the metallic ductility which was similar to aluminium. From the above-mentioned reason, AFRP attracts attention as reinforced composite polymer material. Several recent works on various FRP(s) subject to tensile impact loading are performed [1], [2], [3].

Analysis of locus and strain of left ventricular wall motion by MR tagg-image

The research was focused on the left ventricular wall motion. One heart period was considered, and the movement of pixel intensity between two sequential images was visibility by the optical flow calculation. The transition in the micro-space, locus tracing and principal strain were calculated to evaluate the dynamics of the myocardial wall motion. Deformation around the anti-watch can better be detected by optical flow images than by the indication vector with the image of the ejection early phases, and anterior and septal were greatly indicated. It is explained by a slightly different phase from each of the base, middle and apex. It goes in the center direction inside pericardial cavity in lateral posterior, and a vector was indicated in equator part (middle) and apex. It was understood it puts it on the apex from base, and about transition quantity of the locus tracing increases from the viewpoint of grade and it was doing in the image of locus tracing calculation.

Modelings of Fiber Deformation During Machining Aramid-FRP

Recently, composite materials are used in very widely. But the machining the composite materials is very difficult due to the difference of machinability and of mechanical properties between the fiber and matrix materials. Especially, machining the Aramid Fiber Reinforced Plastics (A-FRP) causes the poor machined surface by large fluffs of Aramid fiber[1] as shown in Fig.1(A). In this paper we tried to clarify the fracture phenomena of Aramid fiber during machining to suggest an optimum machining conditions. We observed the deformation of Aramid fiber bundle inside of the matrix in transparently during machining by using optical microscope. By this method, we can observe the deformation of Aramid fiber and delamination between fiber and matrix clearly as shown in Fig.1(B).

Deformation Analysis of Human Left Ventricular Wall Using Magnetic Resonance Tagging Technique

The deformation of the left ventricular wall in normal humans and several kinds of patients with the heart disease was analyzed by using the magnetic resonance tagging technique. From the obtained results, it was confirmed that the characteristic of the cardiac contractility in each heart disease was reflected in the deformation behavior of the myocardial wall. This study suggests that to evaluate the cardiac contractility from a mechanical point of view is useful for the quantitative evaluation of the heart disease.

Motion and Strain Analyses of Left Ventricular Wall Using Optical Flow

As for the cardiac muscle can be returned continuously has such complicated movement as contraction, expansion, rotation and twist as several decades, and it is very excellent in durability and functionally. So, you must analyze the movement of heart quantitatively in order to elucidation of cardiac function. Therefore, by this research, it pays attention to the left ventricle in which occupies major location as an intracorporeal sanguineous cyclicus pump function, which lasts for one heart period is taken as the imagines. And the movement of left ventricle has imaging in 2 images space to continue during the heart period, intensity modulation of pixel, visibility turns by Optical Flow calculation. Evaluation was tried like the dynamics of myocardial wall motion, about the transition in micro space, locus tracing, and principal strain were calculated. An analytic region divides short axis 3 cross section of heart in four area of anterior, lateral, posterior, and septal, which the lattice point of tagg in brightness grade were thought to be big about endcardium side and epdcardium side respective were connected with was counted in the whole area of triangular.

Computational Analysis for Mechanical Functions of Left Ventricle

A numerical simulation system using the three-dimensional finite element method (3D-FEM) is established to reproduce the performance of the left ventricle during one cardiac cycle, which may ultimately provide useful information for medical diagnoses. The simulation system consists of a 3D-FEM mechanical model of the left ventricle based on four fundamental models, that is, (1) a mechanical model of myocardial muscle fiber which produces the active force, (2) a mechanical model of the left ventricle which is composed of the myocardial muscle fiber, (3) a transmission model of electric stimulus, and (4) a circulatory system model which gives the pre-and after-loads to the left ventricular model. In this chapter, the fundamental system of the simulator is explained, and some typical examples of computational results obtained by this system are shown and discussed. The reliability of the simulator is examined by comparing some numerical results with the corresponding results obtained by medical imaging technique.

Numerical Simulator for Left-Ventricular Functions

A numerical simulation system using the three-dimensional finite-element method (FEM) is established to reproduce the performance of the left ventricle during one cardiac cycle, which may ultimately provide useful information for medical diagnoses. The simulation system consists of a 3-D-FEM mechanical model of the left ventricle based on four fundamental models: (1) a mechanical model of myocardial muscle fiber, which produces the active force; (2) a mechanical model of the left ventricle, which is composed of the model muscle fiber; (3) a transmission model of electric stimulus, and (4) a circulatory system model that provides the after- and preloads for the left-ventricular model. In this chapter, the fundamental system of the simulator is explained, and some typical examples of computational results obtained by this system are shown and discussed. The reliability of the simulator is examined by comparing some numerical results on pressure-volume relationships for different peripheral vascular resistances, aortic compliances, and characteristic impedances with the corresponding experimental results obtained from a canine heart.