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his paper presents a mathematical model of a piezo-plate energy-harvesting scheme. An analytical method is used to generate a finite element model of the coupled piezoelectric sensor element using Love-Kirchhoff΄s plate theory. Constitutive equations for a single layer plate element are formulated. The polarisation of the piezoelectric sensor bounded on the upper plate structure is due to ambient vibration exerted on the structure. Forced vibration of the smart structure will create strain energy within the crystalline structure of the piezoelectric material. The resulting electric field generated by the sensor element was mO΄Delled using a linear thickness interpolation function and the meshed plate elements were mO΄Delled using four-node rectangular elements with three degrees of freedom for each node. The structural eigenmodes and dynamic response of the coupled piezo- plate system were solved by using modal analysis and Newmark-β integration methods respectively. The analysis is demonstrated with both dynamic displacement and electric voltage responses to an applied step force. Further mO΄Delling of the smart structure is aimed at maximising the power generation capability. [ABSTRACT FROM AUTHOR]

Dynamic behaviour of golf balls during oblique impact is investigated using Abaqus (FEA software) to represent the ball structure and measured material properties. The properties of the mantle layer were measured from independent tests of material properties. Materials of golf balls were shown to possess viscoelastic and hyperelastic (or visco-hyperelastic) behaviours. The merit of this approach is that characterisation of new materials and modelling impact of a golf ball can be performed before construction of a prototype golf ball. This paper compares calculated and experimental coefficients of restitution (COR) of a hollow, multilayer golf ball. [ABSTRACT FROM AUTHOR]

In this paper, force planning for underground articulated robot is studied and the governing equations of interaction between motion and soil-structure are formulated. The objective is to develop a new swerving manner in virtue of soil-structure interaction, which affects the behavior of the underground articulated robot in path tracking. The system inputs are the thrust forces on the rear and the articulation actuator. Consideration of the machine-soil interaction allows for the representation of the drift-off course due to swerving typically observed in shield tunnelling. A general force-planning model is established for path tracking of shield machine. Lastly, a simulation is adopted to show the real states during excavating. [ABSTRACT FROM AUTHOR]

Development, finite element(FE) analysis of magnetic field distribution, performance, control and testing of a new axial flux permanent magnet linear oscillating motor (PMLOM) along with a suitable speed and thrust control technique is described in this paper. The PMLOM can perform precision oscillation task without exceeding the given limit on allowable average power dissipation. The use of new powerful permanent magnet materials such as Neodymium-Iron-Boron alloys can greatly improve the performance of electrical machines. Also its performance parameters, such as the force, current etc. are experimentally assessed. The objective of this paper is to determine the forces for aluminium mover embedded with rare earth permanent magnet experimentally and analytically through FEMM software and develop a microcontroller based IGBT Inverter for its control. [ABSTRACT FROM AUTHOR]

The paper deals with the application of the reference stress method (RSM) to estimate the J and C integrals of cracked thick-walled metal as well as medium density polyethylene (MDPE) pipes. Unlike the existing solutions, the newly developed analytical approximations of the plastic limit pressure and J-integral are applicable to a wide range of crack dimensions. Based on the experimental data from literature and analogy between plasticity and creep, the paper discusses a method used to develop the efficient computational strategy for modeling creep fracture mechanisms by slow crack growth in a MDPE pipes. [ABSTRACT FROM AUTHOR]

A direct approach to using finite element analysis (FEA) to predict organ motion typically requires accurate boundary conditions, which can be difficult to measure during surgical interventions, and accurate estimates of soft-tissue properties, which vary significantly between patients. In this paper, we describe a method that combines FEA with a statistical approach to overcome these problems. We show how a patient-specific, statistical motion model (SMM) of the prostate gland, generated from FE simulations, can be used to predict the displacement field over the whole gland given sparse surface displacements. The method was validated using 3D transrectal ultrasound images of the prostates of five patients, acquired before and after expanding the balloon covering the ultrasound probe. The mean target registration error, calculated for anatomical landmarks within the gland, was 1.9mm. [ABSTRACT FROM AUTHOR]

This paper outlines the use of finite element analysis to describe the heat transfer in footwear. Experiments were conducted to determine the temperature distribution in footwear with a variety of environmental temperature and footwear properties considered. Finite element models describing the heat transfer between the foot, sock and shoe are presented with the conductivity, specific heat and density properties of each material presented taken from literature. Based on foot geometry obtained from plaster casts, these models predicted temperatures within footwear with conduction, convection and radiation taken into account. Results from the models were compared with experimental findings with generally good agreement; however the models were limited by a simplified heat input value based on whole body values which did not account for the counter current heat exchange and also by the absence of evaporation as a mode of heat transfer which was significant in hotter conditions. A sensitivity analysis on the heat transfer models showed that the major contributors to the in-shoe conditions under dry heat transfer were the ambient temperature and the initial temperatures of the foot, while the heat flux and sock conductivity also had a minor affect. Further studies are required to include the effects of evaporation and to include the counter current heat exchange as a control for heat input to the foot. [ABSTRACT FROM AUTHOR]

In this paper we present a biomechanical model of isolated breast tumours under mammographic compression forces. We apply a range of reported mechanical properties, both linear elastic and hyperelastic. We also introduce a volume of increased density/stiffness around the tumour. These variables have a non-negligible effect on stresses and strains, as shown in this work. [ABSTRACT FROM AUTHOR]

Touching for prosthetics and social robotics is important for functional and social reasons. Current synthetic finger designs, however, are too stiff when compared to the human touch. We ask whether it would be possible for synthetic skins to mimic the skin compliance of the human finger phalanx. In this paper, finite element simulations were conducted on finger phalanx models with open pockets of 1 mm and 2 mm heights in the internal geometry. With an open pocket design, simulation results show that it is possible to have force-displacement results that are comparable to the published data of the human finger phalanx under cyclic loading. [ABSTRACT FROM AUTHOR]

Prediction of tool wear in rapid production of sheet metal stamping in automobile industries is a highly challenging task as there are many control parameters involved in the production of automotive panels. This paper presents a numerical simulation methodology to investigate the effects of various processing parameters, such as the lubrication, binder pressure and surface coating, on the critical tool worn area of a certain sheet metal stamping die used in automotive production. The simulation was performed using the finite element software AutoForm™. Various contact pressure distributions and tool wear predictions at the critical tool worn section of the die-workpiece interface, using different processing parameters, were obtained in the simulation, which provide informative guidelines for the on-site production. [ABSTRACT FROM AUTHOR]

The effect of autofrettage on thick-walled cylinders, operating under high internal pressure, has become a significant area of development, both in research and practice. In optimal design of thick-walled cylinders, there are two main objectives to be achieved: increasing its strength-weight ratio and extending its fatigue life. This can be achieved by generating a residual stress field in the cylinder wall prior to use. Both analytical and numerical techniques have been used for the investigation of the effects of residual stresses on the load-carrying capacity. The scope of the current paper includes application of ABAQUS finite element code to the direct problem of finding thick-walled cylinder autofrettage solutions. The results reveal three scenarios in the design of thick-walled cylinders. For maximum load carrying capacity, non-autofrettage is suitable when, in service, the whole wall thickness will be yielded. Full autofrettage is suitable when, during subsequent operation, yielding is limited at the inner surface. Optimum autofrettage of the cylinder is suitable if a minimum equivalent stress is to be achieved. The analytical solutions were compared to numerical results and a very good correlation in form and magnitude was obtained. [ABSTRACT FROM AUTHOR]

In this paper, the load transmission model of the shield thrust system is established taking into account the variable boundary constraints between the shield skin and the surrounding strata, which is obtained based on the finite element methods. The results show that the resisting moment on the shield skin from the geologic layer has a nonlinear relationship with the bending moment loads on the cutterhead when the material behavior of the strata is modeled by an elasto-plastic Mohr-Coulomb model. The dynamic load behavior of the shield thrust system is significantly influenced by the variable shield-strata boundary constraints, which may cause incorrect load predictions of the hydraulic thrust system and consequent snake-like motions of the shield machine. [ABSTRACT FROM AUTHOR]

Synthetic skins with humanlike characteristic would make it possible to address some of the psychosocial requirements of prosthetic hands as well as the safety and acceptance issues in social robotics. This paper describes the development of three-dimensional finite element models of synthetic finger phalanges. With the aim of duplicating the skin compliance of human finger phalanges, the model was used to investigate the effects of (i) introducing open pockets in the internal structure and (ii) combining different materials as external and internal layers. The results show that having pockets in the internal structure of the design can increase the skin compliance of the synthetic phalanges and make it comparable with the human counterpart. Moreover, having different layers can be used to satisfy skin compliance and other design requirements such as wear and tear. [ABSTRACT FROM AUTHOR]

This paper presents an experimental and a finite element analysis which are conducted to determine the allowable and failure pressures in unflawed valve housing (designation DN100 PN40). Extensive three-dimensional non-linear finite element analyses are performed to obtain the plastic limit, collapse and instability loads for valve housing under internal pressure and to predict the burst pressure obtained by the experimental tests. Finite element results show that the failure pressures obtained by limit load analyses give conservative results, except those obtained by using ultimate tensile stress as the flow stress. It is shown that the plastic collapse pressure results obtained by a real strain hardening material model agree well with the experimental results. [ABSTRACT FROM AUTHOR]

3D-coordinate Measuring Machine (CMM) is affected by various heat sources in high-speed measuring, which results in deformation of the machine and measurement errors. This paper makes a theoretical analysis on the thermal error produced during the CMM΄s work process. And the thermal deformation of CMM is analyzed with Finite Element Method (FEM). A thermal error compensation model is also established by multi-body theory. Meanwhile integral mean value theorem is used to establish a mathematical model of the thermal expansion of the drive screw, and the CMM measurement accuracy is improved. [ABSTRACT FROM AUTHOR]

This paper presents a new method for the signature analysis of mechanical watch movements. Contrary to the existing method, it analyzes the time-frequency features of mechanical watch movement through a combination of reassigned scalogram and Finite Element Analysis (FEA). By mapping the signal into a 2D domain of time and frequency, the reassigned scalogram reveals the frequency components of the shocks at different time. On the other hand, FEA gives the modal frequencies of the movements. By comparing the frequency components at different shocks to the modal frequencies of the movement, possible malfunctions of the movement can then be detected. A number of demonstration examples are included. [ABSTRACT FROM AUTHOR]

An explicit finite-element (FE) model of a pressurised tennis ball was produced in Ansys/LS-DYNA 10.0 and validated at room temperature. This model was successfully updated to simulate temperatures of 283.15 and 313.15 K (10 and 40 °C), by adjusting the internal pressure and material properties of the ball΄s rubber core. The validation experiment was undertaken using an impact rig in a climate chamber, for perpendicular impacts on a rigid surface with inbound velocities in the range from 15 to 30 m·s-1. The impact rig consisted of an air-cannon, for firing the balls, a set of light gates for calculating coefficient of restitution (COR), and a force plate for measuring contact time. The model was found to be in good agreement with the experimental data across the entire range of temperatures tested. [ABSTRACT FROM AUTHOR]