Commercial Finite Element Modeling Software Research Articles

Simulation of controlled modulus column installation using a large deformation finite element analysis

Controlled modulus columns (CMC) are widely used in ground improvement techniques where grout columns are constructed by penetrating an auger into the ground using the displacement approach. Numerical simulation of this problem is challenging owing to the large soil deformations associated with installation. Small strain-based finite element analysis procedures available in commercial finite element modeling software are unsuitable for simulating this problem because they cannot simulate large soil deformations around the auger during column installation. Hence, this study presents a numerical approach based on the finite element method to simulate the installation of CMCs. The numerical modeling technique adopted in this study considers large soil deformations around columns during penetration, and the proposed approach is based on remeshing and interpolation techniques. This method was developed using the Python development environment (PDE) within the ABAQUS/standard finite element program. It can penetrate columns below the ground surface without causing large mesh distortions. In this study, silty sand-type soil was considered; hence, the constitutive behavior was simulated using the Mohr–Coulomb criteria. The load-carrying capacity of a controlled modulus column was predicted and compared with an empirical equation based on the cone penetration resistance. The influence zone and failure mechanism of the soil during installation were determined by considering the stress distribution and soil flow pattern around the column.

Experimental and Analytical Study of Grouted Sleeve Splice Under Axial Tensile Load

Paper Compared to traditional cast-in-place concrete structures, the precast Concrete structures are usually constructed in a controlled environment , i.e. plants, and then assembled through certain links at the construction site. The concrete precast concrete structures can therefore have better concrete quality and help to reduce labor costs and increase construction speed. Because of these advantages, in recent years the precast concrete structures have received much attention. This research work therefore presents a reasonable procedure for designing a grouted sleeve splice connection using a simple material such as standard pipes with little workmanship which gives the design a good advantage compared to just using selection tables for expensive proprietary similar connection. Such splices’ mechanical behavior is a function of two essential mechanisms: bar-to-grout bond behavior, and sleeve-to-grout bond behavior. To achieve the purpose of this analysis work , three arrangements were manufactured and checked under incremental axial tensile load with an all-out number of 66 grouted splice sleeve specimens. While experimental methods of investigation are extremely useful in obtaining information about the grouted splice sleeve connection behavior, the use of numerical models helps to develop good comprehension of behavior at lower cost. Models of non-linear finite-element analysis for grouted splice sleeve connection were presented in this research. The research utilized the commercial Finite Element modeling software (ANSYS) to study the effects of some parameters that are important in the bond behavior of the grouted splice sleeve connection and compare the analytical results with the experimental results to confirm the analytical model. The average efficiency of the finite element models using ANSYS was 92.5%. Having the finite element model validated, a parametric study was performed using ANSYS to evaluate the effect of the following parameters on the behavior of grouted splice sleeve: bar diameter, embedded length, grout compressive strength, sleeve wall thickness, and sleeve inner diameter.

Multi‐physics and multi‐objective optimisation design of interior permanent magnet synchronous motor for electric vehicles

The electrical machine design method plays a decisive role in electric vehicles (EVs). However, only a few designs consider the coupling of multiple fields simultaneously. This study proposes an improved multi-physics and multi-objective optimisation design approach for designing a 75 kW interior permanent-magnet synchronous machine dedicated to EVs. Five optimal objectives including power density, temperature rise, price, torque ripple, and cogging torque are selected, and the first three objectives are optimised based on the sensitivity analysis of design parameters, where an improved thermal resistance network combining with finite-element analysis model is developed. Meanwhile, the torque ripple and cogging torque are involved in subsequent design optimisation. The temperature rise and structural strength are recalculated by using commercial finite-element model software, respectively, for validating the accuracy of optimisation design. Finally, a prototype motor is manufactured; both simulation and experimental results verify the feasibility and validity of the proposed optimisation design method.

Characterization of rotor losses in permanent magnet machines

PurposeThe purpose of this paper is to present a synthesis of the analysis and modeling of the rotor losses in high speed permanent magnets motors.Design/methodology/approachThree types of losses are as a result of eddy currents in the conductive parts of the rotor. The analysis includes their characterization and the setup of a numerical model using finite element method. The adopted methodology is based on the separation of the losses which allows a better understanding of the physical phenomena. Each type of losses will be modeled and computed separately.FindingsIt is possible to make a precise estimate of the different losses in the rotor while keeping a relatively short computing time.Research limitations/implicationsThe analysis is applied on a high-speed permanent magnet motor for avionic application. The model is validated with the commercial finite element model (FEM) software Flux2D.Originality/valueThe developed model allows an important save in terms of CPU-time compared to commercial FEM software while staying accurate. The separation of each losses and their sources is important for motor engineers and was requested for them to improve the designs more easily.

Realistic volumetric-approach to simulate transcranial electric stimulation—ROAST—a fully automated open-source pipeline

Objective. Research in the area of transcranial electrical stimulation (TES) often relies on computational models of current flow in the brain. Models are built based on magnetic resonance images (MRI) of the human head to capture detailed individual anatomy. To simulate current flow on an individual, the subject’s MRI is segmented, virtual electrodes are placed on this anatomical model, the volume is tessellated into a mesh, and a finite element model (FEM) is solved numerically to estimate the current flow. Various software tools are available for each of these steps, as well as processing pipelines that connect these tools for automated or semi-automated processing. The goal of the present tool—realistic volumetric-approach to simulate transcranial electric simulation (ROAST)—is to provide an end-to-end pipeline that can automatically process individual heads with realistic volumetric anatomy leveraging open-source software and custom scripts to improve segmentation and execute electrode placement. Approach. ROAST combines the segmentation algorithm of SPM12, a Matlab script for touch-up and automatic electrode placement, the finite element mesher iso2mesh and the solver getDP. We compared its performance with commercial FEM software, and SimNIBS, a well-established open-source modeling pipeline. Main results. The electric fields estimated with ROAST differ little from the results obtained with commercial meshing and FEM solving software. We also do not find large differences between the various automated segmentation methods used by ROAST and SimNIBS. We do find bigger differences when volumetric segmentation are converted into surfaces in SimNIBS. However, evaluation on intracranial recordings from human subjects suggests that ROAST and SimNIBS are not significantly different in predicting field distribution, provided that users have detailed knowledge of SimNIBS. Significance. We hope that the detailed comparisons presented here of various choices in this modeling pipeline can provide guidance for future tool development. We released ROAST as an open-source, easy-to-install and fully-automated pipeline for individualized TES modeling.

Design of VCM actuator for optical zooming smartphone cameras

The function of optical zooming is really rare in smartphone cameras due to its appearances and dimensions now. The manufactures need to provide a better optical performance and make a new gimmick to attract consumers. As a result, a novel VCM actuator with optical zoom for smartphone cameras is proposed in this paper, it has a simpler structure when compared to stepping motor smartphone cameras. The paper presents a segmented magnetic equivalent circuit method to analyze the magnetic characteristics of proposed VCM actuator and further verified by a commercial finite element model software. Furthermore, the performance of the proposed optical zoom VCM actuator was verified by constructing a laboratory-built prototype, the experimental results shows that the proposed VCM actuator has good positioning accuracy and good dynamic response.

Transient eddy current oscillations method for the inspection of thickness change in stainless steel

Detection and evaluation of corrosion and defects in industrial structures are extremely important for accident reduction and product quality assurance. We propose a new nondestructive testing (NDT) method called transient eddy current oscillations (TECO) to detect a change in thickness of stainless steel. This method uses a charged capacitor to discharge through an induction coil (excitation coil) and the resultant magnetic field detected by using a Hall-effect sensor, which is placed inside the cylindrical excitation coil at the bottom side axial center. Homogeneous stainless steel test specimen of different thicknesses has been prepared to test the feasibility of the TECO method. Three different features were identified in the detected magnetic field signal: envelope (peak amplitudes), zero crossing difference and the energy. Experimental results show a good correlation between detected features and the thickness of the test material. To verify the experimental results, simulations were performed using a commercial finite element modeling software. Results suggest that the proposed method can be a potential NDT tool for the detection of corrosion and wall thickness in industrial structures.

Finite Element Model Analysis of 3-D Angle-Interlock Woven Composite under Quasi-Static Tensile Loading

The tensile response of three-dimensional angle-interlock woven composite (3DAWC) under quasi-static loading was investigated in experimental and finite element model (FEM) analysis. The FEM analysis was based on micro-structure at yarn level and connected with commercial FEM software ABAQUS/Explicit (ver. 6.10) to calculate the tensile property under quasi-static loading. The experimental and FEM stress-strain results were compared. Good agreement proved that the FEM method based on micro-structure was reasonable and effective and could be used to design 3-D woven structural composite.

Characterization of the static behavior of micromirrors under the effect of capillary force, an analytical approach

In this article, the static behavior of micromirrors under the effect of capillary force is studied. The dimensionless equations governing the static behavior and the pull-in state of the micromirror under capillary force are obtained, and the effects of different geometrical parameters on the pull-in angle of micromirrors are investigated. The static behavior of micromirrors is studied both numerically and analytically using the homotopy perturbation method. It is observed that with increasing the instability number defined in this article, the rotation angle of the micromirror is increased and suddenly the pull-in occurs. The results of the presented model are then verified by comparing them with the results of finite element simulations performed in the commercial finite element model software ANSYS. The agreement between the results of finite element model and those of the proposed analytical model shows that homotopy perturbation method can be used as a fast and accurate tool for predicting mirror’s behavior under capillary force.

Finite Element Analysis of Crawler Frame of the Rotary Drill Bits

Commercial finite element modeling software ANSYS was used to calculate the stress and deformation distributions of crawler frame of the Rotary drill bits under turning work condition. By using finite element method, the weak points of the crawler frame can be found and the strength of the model can be calculated quickly and correctly. The results show that the crawler frame has enough strength to support the machine to finish the turning process and the maximum displacement distributed in the middle of the crawler frame. This paper will supply references for the structural optimize design of crawler frame of the rotary drill bits.

Finite Element Analysis of Stress Distributions on the Diamond Pick

Commercial finite element modeling software ANSYS was used to calculate the stress distributions of diamond pick at different loads. The three-dimension model of the pick was built and the direction and magnitude of load were varied to determine their effect on the stress distributions of diamond pick. The results show that the stresses located on the pick increase with the increasing of the normal and lateral pressure, and if the maximum normal pressure and lateral pressure are not higher than 480 kN and 150 kN, respectively, the diamond pick will not be damaged. The results obtained can provide available data for pick selection, design and performance.

Finite element modeling, characterization, and optimization design for the polymer-typed capacitive micro-arrayed ultrasonic transducer

This study constructs a two-dimensional axisymmetric finite element model (FEM) of the polymer-typed capacitive micromachined ultrasonic transducers (P-CMUT). The electromechanical FE model is created using the APDL programming technique. The ANSYS multiphysics solver with sequential approach and the Physics environment files are applied for the solution of the electrostatic-structural coupled-field analysis. Simulations are performed to investigate the operational characteristics, such as collapse voltage and the resonant frequency of the P-CMUT. The numerical results are found to be in good agreement with experimental observation. Having confirmed validity and accuracy of the proposed numerical model, the study of influence of each defined parameter on the collapse voltage and resonant frequency of the P-CMUT are also presented. To solve some conflict problems taken place in diverse physical fields, an integrated multi-objective design method involving electrical and mechanical characterization is developed to optimize the geometric parameters and material properties of the P-CMUT. The optimization search routine conducted using the genetic algorithm (GA) is connected with the commercial FEM software ANSYS to obtain the best design variable using multi-objective functions. The results show that the optimal parameter values satisfy the conflicting objectives of the design procedures, namely to minimize the collapse voltage while simultaneously maintaining a high resonant frequency. Overall, the presented results confirm that the combined FEM/GA optimization approach provides an efficient and versatile means for optimization design of the P-CMUT.

Partitioned viscoplastic-constitutive properties of the Pb-free Sn3.9Ag0.6Cu solder

The partitioned viscoplastic-constitutive properties of the Sn3.9Ag0.6Cu Pb-free alloy are presented and compared with baseline data from the eutectic Sn63Pb37 solder. Steady-state creep models are obtained from creep and monotonic tests at three different temperatures for both solders. Based on steady-state creep results and creep-test data, a transient creep model is developed for both Pb-free and Sb37Pb solders. A one-dimensional (1-D), incremental analytic model of the test setup is developed to simulate constant-load creep and monotonic and isothermal cyclic-mechanical tests performed over various temperatures and strain rates and stresses using a thermome-chanical-microscale (TMM) test system developed by the authors. By fitting simulation results to monotonic testing data, plastic models are also achieved. The comparison between the two solders shows that Sn3.9Ag0.6Cu has much better creep resistance than Sn37Pb at low and medium stresses. The obtained, partitioned viscoplastic-constitutive properties of the Sn3.9Ag0.6Cu Pb-free alloy can be used in commercial finite-element model software.