Zhiguang Cheng, Behzad Forghani, Zhenbin Du, Lanrong Liu, Yongjian Li, Xiaojun Zhao, Tao Liu, Linfeng Cai, Weiming Zhang, Meilin Lu, Yakun Tian and Yating Li
This paper aims to propose and establish a set of new benchmark models to investigate and confidently validate the modeling and prediction of total stray-field loss inside…
Abstract
Purpose
This paper aims to propose and establish a set of new benchmark models to investigate and confidently validate the modeling and prediction of total stray-field loss inside magnetic and non-magnetic components under harmonics-direct current (HDC) hybrid excitations. As a new member-set (P21e) of the testing electromagnetic analysis methods Problem 21 Family, the focus is on efficient analysis methods and accurate material property modeling under complex excitations.
Design/methodology/approach
This P21e-based benchmarking covers the design of new benchmark models with magnetic flux compensation, the establishment of a new benchmark measurement system with HDC hybrid excitation, the formulation of the testing program (such as defined Cases I–V) and the measurement and prediction of material properties under HDC hybrid excitations, to test electromagnetic analysis methods and finite element (FE) computation models and investigate the electromagnetic behavior of typical magnetic and electromagnetic shields in electrical equipment.
Findings
The updated Problem 21 Family (V.2021) can now be used to investigate and validate the total power loss and the different shielding performance of magnetic and electromagnetic shields under various HDC hybrid excitations, including the different spatial distributions of the same excitation parameters. The new member-set (P21e) with magnetic flux compensation can experimentally determine the total power loss inside the load-component, which helps to validate the numerical modeling and simulation with confidence. The additional iron loss inside the laminated sheets caused by the magnetic flux normal to the laminations must be correctly modeled and predicted during the design and analysis. It is also observed that the magnetic properties (B27R090) measured in the rolling and transverse directions with different direct current (DC) biasing magnetic field are quite different from each other.
Research limitations/implications
The future benchmarking target is to study the effects of stronger HDC hybrid excitations on the internal loss behavior and the microstructure of magnetic load components.
Originality/value
This paper proposes a new extension of Problem 21 Family (1993–2021) with the upgraded excitation, involving multi-harmonics and DC bias. The alternating current (AC) and DC excitation can be applied at the two sides of the model’s load-component to avoid the adverse impact on the AC and DC power supply and investigate the effect of different AC and DC hybrid patterns on the total loss inside the load-component. The overall effectiveness of numerical modeling and simulation is highlighted and achieved via combining the efficient electromagnetic analysis methods and solvers, the reliable material property modeling and prediction under complex excitations and the precise FE computation model using partition processing. The outcome of this project will be beneficial to large-scale and high-performance numerical modeling.
Details
Keywords
- New member-set
- TEAM Problem 21 Family
- Overall effectiveness
- Harmonics-DC hybrid excitation
- Magnetic flux compensation
- Load-component
- Shielding
- Stray-field loss
- Additional loss
- Material property under complex excitations
- Electromagnetic fields
- Numerical analysis
- Power losses
- Transient analysis
- Material modeling
- Computational electromagnetics
Xiaojun Zhao, Fanhui Meng, Zhiguang Cheng, Lanrong Liu, Junjie Zhang and Chao Fan
This paper aims to investigate an efficient approach to model the electromagnetic behaviors and predict stray-field loss inside the magnetic steel plate under 3D harmonic…
Abstract
Purpose
This paper aims to investigate an efficient approach to model the electromagnetic behaviors and predict stray-field loss inside the magnetic steel plate under 3D harmonic magnetization conditions so as to effectively prevent the structural components from local overheating and insulation damage in electromagnetic devices.
Design/methodology/approach
An experimental setup is applied to measure all the magnetic properties of magnetic steel plate under harmonic excitations with different frequencies and phase angles. The measurement and numerical simulation are carried out based on the updated TEAM Problem 21 Model B+ (P210-B+), under the 3D harmonic magnetization conditions. An improved method to evaluate the stray-field loss is proposed, and harmonic flux distribution in the structural components is analyzed.
Findings
The influence of the harmonic order and phase angle on the stray-field loss in magnetic steel components are noteworthy. Based on the engineering-oriented benchmark models, the variations of stray-field losses and magnetic field distribution inside the magnetic components under harmonic magnetization conditions are presented and analyzed in detail.
Research limitations/implications
The capacity of the multi-function harmonic source, used in this work, was not large enough, which limits the magnetization level. Up to now, further improvements to increase the harmonic source capacity and investigations of the electromagnetic behaviors of magnetic steel components under multi-harmonic and DC-AC hybrid excitations are in progress.
Originality/value
To accurately predict the stray-field loss in magnetic steel plate, the improved method based on the combination of magnetic measurement and numerical simulation is proposed. The effects of the frequency and phase angle on the stray-field loss are analyzed.
Details
Keywords
Z.N. Cheng, G.Z. Wang, L. Chen, J. Wilde and K. Becker
A viscoplastic constitutive model, the Anand model, in which plasticity and creep are unified and described by the same set of flow and evolutionary relations, was applied to…
Abstract
A viscoplastic constitutive model, the Anand model, in which plasticity and creep are unified and described by the same set of flow and evolutionary relations, was applied to represent the inelastic deformation behavior for solder alloys. After conducting creep tests and constant strain rate tests, the material parameters for the Anand model of the Pb‐rich content solder 92.5Pb5Sn2.5Ag were determined from the experimental data using a nonlinear fitting method. The material parameters for 60Sn40Pb, 62Sn36Pb2Ag and 96.5Sn3.5Ag solders were fitted from the conventional model in the literature where plasticity and creep are artificially separated. Model simulations and verifications reveal that there is good agreement between the model predictions and experimental data. Some discussion on this unified model is also presented. This viscoplastic constitutive model for solder alloys possesses some advantages over the separated model. The achieved Anand model has been applied in finite element simulation of stress/strain responses in solder joints for chip component, thin quad flat pack and flip‐chip assembly. The simulation results are in good agreement with the results in the literature. It is concluded that the Anand model could be recommended as a useful material model for solder alloys and can be used in the finite element simulation of solder joint reliability in electronic packaging and surface mount technology.
Details
Keywords
Yuqing Xie, Lin Li and Shuaibing Wang
To reduce the computational scale for quasi-magnetostatic problems, model order reduction is a good option. Reduced-order modelling techniques based on proper orthogonal…
Abstract
Purpose
To reduce the computational scale for quasi-magnetostatic problems, model order reduction is a good option. Reduced-order modelling techniques based on proper orthogonal decomposition (POD) and centroidal Voronoi tessellation (CVT) have been used to solve many engineering problems. The purpose of this paper is to investigate the computational principle, accuracy and efficiency of the POD-based and the CVT-based reduced-order method when dealing with quasi-magnetostatic problems.
Design/methodology/approach
The paper investigates computational features of the reduced-order method based on POD and CVT methods for quasi-magnetostatic problems. Firstly the construction method for the POD and the CVT reduced-order basis is introduced. Then, a reduced model is constructed using high-fidelity finite element solutions and a Galerkin projection. Finally, the transient quasi-magnetostatic problem of the TEAM 21a model is studied with the proposed reduced-order method.
Findings
For the TEAM 21a model, the numerical results show that both POD-based and CVT-based reduced-order approaches can greatly reduce the computational time compared with the full-order finite element method. And the results obtained from both reduced-order models are in good agreement with the results obtained from the full-order model, while the computational accuracy of the POD-based reduced-order model is a little higher than the CVT-based reduced-order model.
Originality/value
The CVT method is introduced to construct the reduced-order model for a quasi-magnetostatic problem. The computational accuracy and efficiency of the presented approaches are compared.
Details
Keywords
Mengyao Fan, Xiaojing Ma, Lin Li, Xinpeng Xiao and Can Cheng
In this paper, the complex flow evaporation process of droplet impact on the liquid film in a horizontal falling film evaporator is numerically studied based on smoothed particle…
Abstract
Purpose
In this paper, the complex flow evaporation process of droplet impact on the liquid film in a horizontal falling film evaporator is numerically studied based on smoothed particle hydrodynamics (SPH) method. The purpose of this paper is to present the mechanism of the water treatment problem of the falling film evaporation for the high salinity mine water in Xinjiang region of China.
Design/methodology/approach
To effectively characterize the phase transition problem, the particle splitting and merging techniques are introduced. And the particle absorbing layer is proposed to improve the nonphysical aggregation phenomenon caused by the continuous splitting of gas phase particles. The multiresolution model and the artificial viscosity are adopted.
Findings
The SPH model is validated qualitatively with experiment results and then applied to the evaporation of the droplet impact on the liquid film. It is shown that the larger single droplet initial velocity and the smaller single droplet initial temperature difference between the droplet and liquid film improve the liquid film evaporation. The heat transfer effect of a single droplet is preferable to that of multiple droplets.
Originality/value
A multiphase SPH model for evaporation after the droplet impact on the liquid film is developed and validated. The effects of different factors on liquid film evaporation, including single droplet initial velocity, single droplet initial temperature and multiple droplets are investigated.
Details
Keywords
Zhiguang Cheng, Norio Takahashi, Behzad Forghani, Lanrong Liu, Yana Fan, Tao Liu, Qifan Hu, Sheng Gao, Junjie Zhang and Xiaoyan Wang
The purpose of the paper is to give a review of TEAM Problem 21, focus on its extended progress in engineering-oriented developments, and report the new benchmarking activity…
Abstract
Purpose
The purpose of the paper is to give a review of TEAM Problem 21, focus on its extended progress in engineering-oriented developments, and report the new benchmarking activity undertaken by the authors.
Design/methodology/approach
Testing electromagnetic analysis methods; verify computation models; detail the field behavior of typical magnetic structure; benefit to large-scale numerical modeling.
Findings
The calculated results of power loss and magnetic flux for all the member models agree well with the measured ones. The updated Problem 21 Family can now be used to model the saturation effect in the magnetic plate or the lamination by increasing the exciting currents. The new member model P21d-M allows further detailed examination of the electromagnetic behavior inside laminated sheets. The variation of both the iron loss and the magnetic flux with the excitation patterns and magnetic property data can be investigated inside the laminated sheets and the magnetic plate.
Originality/value
In order to model the possible saturation level of magnetic steel using Ar-V-Ar or T-Ω solvers, the exciting currents are increased from 10 to 50 A. In order to model the iron loss and magnetic flux densities inside the laminated sheets, a very simplified model, P21d-M of Problem 21 Family as shown in Figure 2, has been proposed.
Details
Keywords
S. Chen, P. Sun, X.C. Wei, Z.N. Cheng and J. Liu
The purpose of this paper is to fit Coffin‐Manson equation of Sn‐4.0Ag‐0.5Cu lead free solder joint by using results of solders joint reliability test and finite element analysis…
Abstract
Purpose
The purpose of this paper is to fit Coffin‐Manson equation of Sn‐4.0Ag‐0.5Cu lead free solder joint by using results of solders joint reliability test and finite element analysis. Also to present a novel device for solder joint reliability test.
Design/methodology/approach
Two‐points bending test of Sn‐4.0Ag‐0.5Cu lead free solder joint was carried out at three deflection levels by using a special bending tester that can control displacement exactly by a cam system. The failure criterion was defined as resistance of solder joint getting 10 percent increase. The X‐section was done for all failure samples to observe crack initiation and propagation in solder joint. Finite element analysis was presented with ANSYS for obtaining shear strain range, analyzing distribution of stress and strain and supporting experimental results.
Findings
The experimental results indicate that the fatigue life decreased obviously with the displacement increased. By using optical microscope and SEM photographs, two kinds of failure mode were found in solder joint. The majority failure mode took place at the bottom corner of solder joint under the termination of resistor initially, and propagated into the solder matrix. Another failure mode was delamination. It appeared at the interface between the termination of resistor and its ceramic body. The distribution status of stress and strain in solder joint and the calculation results of shear strain range at different deflection levels were obtained from simulation result. The Coffin‐Manson equation of Sn‐4.0Ag‐0.5Cu lead free solder joint was fitted by combining experimental data with result of finite element analysis.
Originality/value
This paper presents Coffin‐Manson equation of Sn‐4.0Ag‐0.5Cu solder joint with two‐points bending test. An effective and economical device was designed and applied.
Details
Keywords
Zhaowei Zhong and Peng Kiong Yip
A three‐dimensional (3D) package consisting of a stack of three silicon chips was conceptually designed. A finite element simulation of this 3D package was conducted in order to…
Abstract
A three‐dimensional (3D) package consisting of a stack of three silicon chips was conceptually designed. A finite element simulation of this 3D package was conducted in order to compare the fatigue lives of the solder joints with those in a typical single flip chip package when subjected to a cyclic thermal loading. It was found that the proposed design of the 3D package was feasible in terms of its mechanical deformation response to the thermal cycle.
Details
Keywords
Yesen Zhu, Cheng-Qing Gu, Jinliang Wang, Xiaohui Xi and Zhenbo Qin
The purpose of this paper is to study the effect of chromium content on the microstructure and corrosion resistance of Ni-Cr coating.
Abstract
Purpose
The purpose of this paper is to study the effect of chromium content on the microstructure and corrosion resistance of Ni-Cr coating.
Design/methodology/approach
Ni-Cr coating was prepared by pulse current electrodeposition with trivalent chromium. On the basis of studying effect of electroplating parameters on composition and morphology, Ni-Cr alloy coatings with various chromium contents were obtained. The microstructure was characterized by scanning electron microscopy, X-ray diffractometer and transmission electron microscopy. Corrosion behavior was studied by potentiodynamic polarization and electrochemical impedance spectroscopy techniques.
Findings
Electrodeposited chromium was solidly dissolved in nickel and refined the grain of the coating. With the increase of Cr content, the corrosion resistance of Ni-Cr coating was enhanced, which is due to the formation of continuous nickel hydroxide and compact chromium oxide passive films.
Originality/value
Ni-Cr alloy coating without penetration crack was prepared in trivalent chromium electrolyte, and the mechanism of its excellent corrosion resistance was proposed.
Details
Keywords
Mohammad A. Gharaibeh and Faris M. Al-Oqla
There are several lead-free solder alloys available in the industry. Over the years, the most favorable solder composition of tin-silver-copper (Sn-Ag-Cu [SAC]) has been vastly…
Abstract
Purpose
There are several lead-free solder alloys available in the industry. Over the years, the most favorable solder composition of tin-silver-copper (Sn-Ag-Cu [SAC]) has been vastly used and accepted for joining the electronic components. It is strongly believed that the silver (Ag) content has a significant impact on the solder mechanical behavior and thus solder thermal reliability performance. This paper aims to assess the mechanical response, i.e. creep response, of the SAC solder alloys with various Ag contents.
Design/methodology/approach
A three-dimensional nonlinear finite element simulation is used to investigate the thermal cyclic behavior of several SAC solder alloys with various silver percentages, including 1%, 2%, 3% and 4%. The mechanical properties of the unleaded interconnects with various Ag amounts are collected from reliable literature resources and used in the analysis accordingly. Furthermore, the solder creep behavior is examined using the two famous creep laws, namely, Garofalo’s and Anand’s models.
Findings
The nonlinear computational analysis results showed that the silver content has a great influence on the solder behavior as well as on thermal fatigue life expectancy. Specifically, solders with relatively high Ag content are expected to have lower plastic deformations and strains and thus better fatigue performance due to their higher strengths and failure resistance characteristics. However, such solders would have contrary fatigue performance in drop and shock environments and the low-Ag content solders are presumed to perform significantly better because of their higher ductility.
Originality/value
Generally, this research recommends the use of SAC solder interconnects of high silver contents, e.g. 3% and 4%, for designing electronic assemblies continuously exposed to thermal loadings and solders with relatively low Ag-content, i.e. 1% and 2%, for electronic packages under impact and shock loadings.