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More and more solid-state magnetic field sensors such as Hall devices are used in eddy current inspection (EC) to acquire magnetic field signals. This work extends the previous analytical model, i.e. 2D Extended Truncated Region Eigenfunction Expansion (ETREE) of EC, and focuses on establishment of 3D ETREE of multi-frequency eddy current inspection (MFEC) on stratified conductors, while taking into account the solid-state magnetic field sensors for field quantification and rectangular coils for field excitation. 3D Finite Element Modelling (FEM) and a hybrid modelling are adopted for verification of the established model. It has been noticed that the 3D ETREE implements the fast and accurate computation of magnetic field signals of MFEC. Following that, the directional characteristics of EC with rectangular excitation coils are investigated, which reveals that the coil width contributes more to the measurement sensitivity than the coil length, and benefits the evaluation of defects and anisotropic conductivity profile of conductors in the follow-up study. [ABSTRACT FROM AUTHOR]

The contribution deals with the development of a 3-D finite-element package called GEM and its aspirations in demanding mathematical modelling and simulations arising in geosciences. On the background of two complex applications from the presently running projects, formulated as linear elasticity and thermo-elasticity problems, the most important characteristics, especially those of the solvers, are presented. Features related to high performance computing, including parallel processing, are focused on. [ABSTRACT FROM AUTHOR]

Impaired systolic ventricular function is common in patients diagnosed with heart failure (HF) or ischaemic heart disease. The diminished contractile performance with impaired contractility (systolic HF) can be induced by impaired filling function (diastolic HF) and the wall stress (both passive and active) may indicate the progression from diastolic HF to systolic HF. In order to better understand the distribution of active stress during ventricular contraction, a left ventricular (LV) finite element (FE) model incorporating LV fibre geometry and function was developed to parameterise a time-varying model of myocardial contraction by simulating LV mechanics. During systole, the isometric active stress monotonically increased to 95 kPa, and rapidly recovered during isovolumic relaxation. We also observed regional variations of the fibre length dependent contractile stress throughout the LV. The time-varying active stress curve thereby obtained enabled quantification of heart muscle performance. This type of integrative modelling enables the investigation of LV mechanics on an individualised basis. [ABSTRACT FROM AUTHOR]

Patients suffering from dilated cardiomyopathy or myocardial infarction can develop left ventricular (LV) diastolic impairment. The LV remodels its structure and function to adapt to pathophysiological changes in geometry and loading conditions and this remodeling process can alter the passive ventricular mechanics. In order to better understand passive ventricular mechanics, a LV finite element model was developed to incorporate physiological and mechanical information derived fromin vivo magnetic resonance imaging (MRI) tissue tagging, in vivo LV cavity pressure recording and ex vivo diffusion tensor MRI (DTMRI) of a canine heart. MRI tissue tagging enables quantitative evaluation of cardiac mechanical function with high spatial and temporal resolution, whilst the direction of maximum water diffusion (the primary eigenvector) in each voxel of a DTMRI directly correlates with the myocardial fibre orientation. This model was customized to the geometry of the canine LV during diastasis by fitting the segmented epicardial and endocardial surface data from tagged MRI using nonlinear finite element fitting techniques. Myofibre orientations, extracted from DTMRI of the same heart, were incorporated into this geometric model using a free form deformation methodology. Pressure recordings, temporally synchronized to the tissue tagging MRI data, were used to simulate the LV deformation during diastole. Simulation of the diastolic LV mechanics allowed us to estimate the stiffness of the passive LV myocardium based on kinematic data obtained from tagged MRI. This integrated physiological model will allow more insight into the regional passive diastolic mechanics of the LV on an individualized basis, thereby improving our understanding of the underlying structural basis of mechanical dysfunction in pathological conditions. [ABSTRACT FROM AUTHOR]

This paper reports the results of an experimental and finite element analysis of tibial screw fixation in hamstring ACL reconstruction. The mechanical properties of the bone and tendon graft are obtained from experiments using porcine/calf bones and tendon. The results of the numerical study are compared with those from mechanical testing. Analysis shows that the model may be used to establish the optimum placement of the tunnel in anterior cruciate ligament reconstruction by predicting mechanical parameters such as stress, strain and displacement at regions in the tunnel wall. [ABSTRACT FROM AUTHOR]