Applied Mechanics and Materials Vol. 707

Abstract: The Grad-Shafranov equation is solved by EFIT code in J-TEXT tokamak. In this paper, it applies EFIT code to analyze the evolution of some plasma parameters during the discharge of J-TXET tokamak. Through plasmas balance calculation, the pressure of plasmas, internal magnetic surface and plasma current density profile are given. It provides important reference data for the operation and control of the J-TXET tokamak discharge.

Abstract: Nowadays, EtherCAT technology is widely used in motion control and industrial automation fields. It has good performance on transmission speed and synchronization between several slave stations. In this paper, an EtherCAT slave station design method based on STM32 MCU and ET1100 chip is carried out from the view of hardware and software. This slave station’s performance of data transmission is fast and stable.

Abstract: In order to satisfy the orientation measuring requirements of rigid-body such as work piece, cutting tool in industry, the paper presents a binocular vision detection technique based on spatial position information of markers to extract rigid-body pose information and analyzes the pose accuracy of rigid-body using the principal component analysis (PCA) when spatial position error of markers exist. The simulation experiment demonstrates the maximum angle error of orientation is about 0.59 degree when the position error of markers satisfy the Gaussian distribution with the mean is zero and the standard deviation is 0~3mm. The experimental results verify this method can robustly solve the orientation of rigid body using the position information of markers with position errors, and it provides a theoretical and experimental basis for orientation measurement of rigid body.

Abstract: The maximum power point tracking (MPPT) of photovoltaic arrays can increase the output power of the photovoltaic systerm, improve the utilization of solar energy. This paper describes the output characteristics of the photovoltaic arrays and the principle of maximum power point tracking,then,based on Incremental conductance method, proposes a sub-type of the variable step size MPPT algorithm. simulated using MATLAB/Simulink, the final results show that the proposed algorithm is able to quickly track the maximum power point and power concussion problem has been significantly improved.

Abstract: Mining Dump truck frame is a key part of the vehicle, in this paper the finite element model of the frame was built in UG software, and then the model was imported into ANSYS Workbench. The paper carried on the statics analysis of the frame under the bending and the torsion condition, and carried on modal analysis under a free state. Through the results of analysis, the design requirements such as the stress condition and each order natural frequency of the frame were verified.

Abstract: Various theories of Quantum Gravity predict the existence of a minimum observable length, or a maximum observable momentum, and the related generalized uncertainty principle (GUP), and it influences all quantum Hamiltonians. Thus, they predict quantum gravity corrections to various quantum phenomena. The GUP gives rise to two additional terms in any quantum mechanical Hamiltonian, proportional toandrespectively, where is the GUP parameter. By considering both terms as perturbations .We compute such corrections to the two typical potentials: parabolic potential toand Dirac potential to. We show that the GUP affects reflection and transmission coefficients of the two potentials.

Abstract: A damage accumulation model is presented for fatigue life prediction of metallic structures. Based on the energy theory and material fatigue test data, the plastic strain threshold for damage initiation was modified for HCF and LCF respectively. The damage evolution parameters were determined according to the fatigue test results of standard specimens. A damage mechanics-finite element full-couple method was adopted to simulate the process of fatigue damage evolution, incorporating elastic modulus reduction due to fatigue damage. Comparisons are made with the fatigue tests of 2A12-T4 open-hole plates and good agreement was obtained.

Abstract: This article introduced the up-to-date research progress on the tool-soil interacting problem of tillage; and investigated the situation of constitutive relation usage in the finite element method (FEM). A review including the dynamic effect on the performance of tillage operation with FEM has been conducted. It showed that the virtual reality method with FEM had made much progress in evaluating the tool draft, distribution position of stress and strain, displacement fields and acceleration in soil-tool interactions, soft ware package of computer aided design of tillage tools; it will be a low cost and high efficiency assistive tool in the development procedure of tillage tools, and can be applied to study and analyze the performance of resulting prototypes.

Abstract: Using the finite element software ANSYS to establish the model of prestressed concrete T beam .With the combination of dynamic and static load test data, the objective function was constructed by taking the vertical deflection of the static load test and the top five vertical natural frequency of dynamic test as state variables. The results revealed that,after being modified ,the error between the calculation value and the testal results of the model was converged in a reasonable error range.In addition ,The modified model could be used in the assessment of bridge structure performance,and it shows the practical application value.

Abstract: In order to achieve the acoustic comfort design for ship accommodation areas, This paper introduces the noise prediction of ship’s superstructure cabins based on boundary element method (BEM). The study investigates the ship acoustic responses due to fluctuating forces induced as a result of interaction between a 4-bladed propeller and Bulk Carrier ship 35,000DWT at full scale. The mathematical models for the ship and the propeller have been built and validated using computational fluid dynamics (CFD), then unsteady simulation done to obtain the transient responses of the propeller excitations. Finally, the acoustic responses of ship super structure under propeller excitations are predicted using BEM in time domain. This work shows a numerical method enable to measure the structural and acoustic responses of the ship at propeller rotating speeds. In addition, at the structural resonating modes of the propeller and the ship. As the propulsion system is the main source of the ship exciting forces thereby nowadays prediction of the ship low frequency noise due to propulsion system becomes important to naval designer for designing a comfort accommodation areas for the crew onboard the ship.