Study of Electromigration-Induced Stress of Solder

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Fei Su ◽  
Zheng Zhang ◽  
Yuan Wang ◽  
Weijia Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Temperature Gradient ◽  
Inelastic Deformation ◽  
Comprehensive Evaluation ◽  
Vacancy Concentration ◽  
Fem Model ◽  
Induced Stress ◽  
Simulation Results ◽  
Solder Reliability

This study designed and produced a special microsolder specimen (Sn3.8Ag0.7Cu) to equalize current density under stressing. The specimen was generated to avoid temperature gradient and thermal migration. The inelastic deformation of the solder with electromigration (EM) alone was then measured with moiré interferometry. In addition, the EM-induced solder stress was evaluated using a finite element method (FEM). The precision of the FEM model was verified by comparing the simulated results with the experimental results with respect to EM-induced deformation. Findings indicated that the maximum spherical stress in the solder can reach 50 MPa. Moreover, the vacancy concentration is much higher on the cathode end than on the anode end. The simulation results can illustrate the failure mode of a solder and can therefore provide a basis for the comprehensive evaluation of solder reliability under EM.

Compressive Strength Analysis of MWD Microchip Tracer

2014 ◽  
Vol 511-512 ◽  
pp. 561-564
Author(s):  
Ji Bo Li ◽  
Wei Ning Ni ◽  
San Guo Li ◽  
Zu Yang Zhu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Compressive Strength ◽  
Working Conditions ◽  
Failure Criterion ◽  
Strength Analysis ◽  
Design Phase ◽  
Key Issues ◽  
Simulation Results ◽  
Better Than

Pressure resistant performance of Measure While Drilling (MWD) microchip tracer to withstand the harsh downhole environment is one of the key issues of normal working. Therefore, it is an effective way to analyze pressure resistant performance of the tracer in the design phase. Compressive strength of the tracer was studied based on finite element method. Considering downhole complexity and working conditions during the processing of tracer roundness, material non-uniformity and other factors. In this study, researchers took sub-proportion failure criterion to determine the failure of tracer. Simulation results of two structures, with pin and without pin, show that both structures met the requirement of downhole compressive strength, and the structure with pin was better than the structure without pin. This study provides basis for downhole application of microchip tracers.

scholarly journals STUDI BANDING PERFORMA TIANG UTAMA BUS UNTUK MODEL TUNGGAL DAN MODEL GANDA DENGAN MENGGUNAKAN SIMULASI METODA ELEMEN HINGGA

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Budi Setiyana
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fem Model ◽  
Element Method

Sehingga setiap komponen dari bus harus memiliki struktur rangka yang kuat terutama pada tiang utama. Masing-masing tiang utama umumnya dibuat dari sebuah baja profil tunggal (model tunggal). Tetapi tiang utama bus ini juga dapat dibuat dari gabungan dua buah baja profil dengan cara di las (model ganda) yang mempunyai dimensi luar yang sama dengan model tunggal. Penelitian ini bertujuan memodelkan dan membandingkan performa tiang utama sebuah bus untuk tiang model tunggal dan model ganda dengan menggunakan FEM (Finite Element Method). Hasil simulasi FEM adalah berupa tegangan dan displacement. Berdasarkan hasil analisis, didapatkan tegangan dan displacement pada tiang utama model tunggal yaitu berturut turut sebesar 1,287 x 106 N/m2 dan 6,448 x 10-1 mm. Sedangkan tegangan dan displacement pada tiang utama model ganda yaitu berturut turut sebesar 2,936 x 106 N/m2 dan 1,580 mm.  Dari hasil simulasi, bentuk rangka tiang utama yang terbaik adalah tiang utama model tunggal karena memiliki tingat keamanan yang tinggi dibandingkan dengan tiang model ganda baik dari sisi tegangan maupun displacement.Kata kunci: FEM, model tunggal, model ganda, tiang utama

scholarly journals DESAIN DAN ANALISIS TEGANGAN STRUKTUR CRANE KAPASITAS 10 TON MENGGUNAKAN METODE ELEMEN HINGGA

2020 ◽  
Vol 4 (2) ◽  
pp. 201
Author(s):  
Lasinta Ari Nendra Wibawa
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mild Steel ◽  
Von Mises Stress ◽  
Assembly Process ◽  
Heavy Equipment ◽  
Steel Material ◽  
Simulation Results ◽  
Heavy Loads ◽  
Von Mises

Crane is one of the heavy equipment that is widely used in the industry. The crane functions as a tool for lifting heavy loads and moving them from one place to another vertically and horizontally. In the LAPAN Garut office, it is used for the rocket assembly process. The study investigates the design and analysis of von Mises stress of crane structure with a capacity of 10 tons using mild steel material. The investigation was carried out numerically using Autodesk Inventor Professional 2017. The simulation results showed the Crane structure had a von Mises stress, deformation, mass, and safety factor respectively 63.73 MPa; 2,173 mm; 1.508,53 kg; and 3.25.Keywords: autodesk inventor 2017; finite element method; mild steel; stress analysis; von Mises stressABSTRAKCrane merupakan salah satu alat berat yang banyak digunakan dalam suatu industri. Crane berfungsi sebagai alat untuk mengangkat beban berat dan memindahkannya dari satu tempat ke tempat lain secara vertikal maupun horisontal. Di LAPAN Garut, Crane digunakan untuk proses perakitan roket. Penelitian ini meneliti tentang perancangan dan analisis tegangan von Mises struktur Crane dengan kapasitas 10 Ton menggunakan material mild steel. Analisis dilakukan secara numerik dengan menggunakan perangkat lunak Autodesk Inventor Professional 2017. Hasil simulasi menunjukkan struktur Crane memiliki tegangan von Mises, deformasi, massa, dan factor keamanan berturut-turut sebesar 63,73 MPa; 2,173 mm; 1.508,53 kg; dan 3,25.

scholarly journals Modelling of triaxial fracture processes in heterogeneous quasi-brittle materials using the Embedded Finite Element Method (E-FEM)

2021 ◽  
Author(s):  
Alejandro Ortega Laborin ◽  
Yann MALECOT ◽  
Emmanuel ROUBIN ◽  
Laurent DAUDEVILLE
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Spherical Inclusion ◽  
Brittle Materials ◽  
Three Dimensions ◽  
Strong Discontinuity ◽  
Homogeneous Material ◽  
Fem Model ◽  
Fracture Processes ◽  
Element Method

This paper studies the use of the Embedded Finite Element Method (E-FEM) for the numerical modelling of triaxial fracture processes in non-homogeneous quasi-brittle materials. The E-FEM framework used in this study combines two kinematics enhancements: a weak discontinuity allowing the model to account for material heterogeneities and a strong discontinuity allowing the model to represent local fractures. The strong discontinuity features enriched fracture kinematics that allow the modelling of all typical fracture modes in three dimensions. A brief review is done of past work using similar enriched finite element frameworks to approach this problem. The work continues by establishing the theoretical basis of each kind of discontinuity formulation and their superposition through the Hu-Washizu variational principle. Afterwards, two groups of simulations have been done for discussing the performance of this combined E-FEM model: homogeneous simulations and simple heterogeneous simulations. Simple homogeneous material simulations aim to test the capabilities of the strong discontinuity model featuring full 3-D kinematics. Simple heterogeneous simulations show numerical applications of the model to the problem of a single spherical inclusion embedded into a homogeneous matrix. Comparisons will be made with another E-FEM model considering a single local fracture mode approach to discuss the differences on the representation of fracture physics under all explored conditions. A concluding statement is made on the benefits and complications identified for the E-FEM framework in this kind of applications.

Auditory startle disrupts speech coordination

2021 ◽  
Vol 47 (2) ◽  
pp. 167-183
Author(s):  
Chenhao Chiu ◽  
Bryan Gick
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Human Body ◽  
Biomechanical Model ◽  
Induced Responses ◽  
3D Finite Element ◽  
Jaw Opening ◽  
Simulation Results ◽  
Temporal Interaction ◽  
3D Finite Element Method

Abstract Speech production requires temporal coordination between the actions of different functional groupings of muscles in the human body. Crucially, such functionally organized units, or “modules”, may be susceptible to disruption by an external stimulus such as a startling auditory stimulus (SAS; >120dB), enabling a possible window into the internal structure of learned speech movements. Following on the observation that SAS is known to accelerate the release of pre-planned actions, the current study examines lip kinematics in SAS-induced responses during speech movements to test whether this accelerated release applies on the scale of entire syllables or on the scale of smaller functional units. Production measures show that SAS-elicited bilabial movements in [ba] syllables are prone to disruption as measured by discontinuity in velocity profiles. We use a 3D finite element method (FEM) biomechanical model to simulate the temporal interaction between muscle groupings in speech. Simulation results indicate that this discontinuity can be accounted for as an instance of temporally decoupled coordination across neuromuscular modules. In such instances, the muscle groupings controlling lip compression and jaw opening, which normally fire sequentially, appear more likely to be activated synchronously.

scholarly journals Analysis and Optimization of Tooth Surface Contact Stress of Gears with Tooth Profile Deviations, Meshing Errors and Lead Crowning Modifications Based on Finite Element Method and Taguchi Method

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1370
Author(s):  
Qiang Li ◽  
Liyang Xie
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Taguchi Method ◽  
Contact Stress ◽  
Influence Factors ◽  
Optimal Combination ◽  
Tooth Surface ◽  
Single Factor ◽  
Fem Model ◽  
Influence Degree

Based on the three-dimensional (3D) finite element method (FEM) and Taguchi method (TM), this paper analyzes the tooth surface contact stress (TSCS) of spur gears with three different influence factors: tooth profile deviations (TPD), meshing errors (ME) and lead crowning modifications (LCM), especially researching and analyzing the interactions between TPD, ME and LCM and their degree of influence on the TSCS. In this paper, firstly, a 3D FEM model of one pair of engaged teeth is modeled and the mesh of the contact area is refined by FEM software. In the model, the refined area mesh and the non-refined area mesh are connected by multi-point constraint (MPC); at the same time, in order to save the time of the FEM solution on the premise of ensuring the solution’s accuracy, the reasonable size of the refined area is studied and confirmed. Secondly, the TSCS analyses of gears with one single influence factor (other factors are all ideal) are carried out. By inputting the values of different levels of one single factor into the FEM model, especially using the real measurement data of TPD, and conducting the TSCS analysis under different torques, the influence degree of one single factor on TSCS is discussed by comparing the ideal model, and it is found that when the influence factors exist alone, each factor has a great influence on the TSCS. Finally, through TM, an orthogonal test is designed for the three influence factors. According to the test results, the interactions between the influence factors and the influence degree of the factors on the TSCS are analyzed when the three factors exist on the gear at the same time, and it is found that the TPD has the greatest influence on the TSCS, followed by the lead crowning modified quantity. The ME is relatively much small, and there is obvious interaction between ME and LCM. In addition, the optimal combination of factor levels is determined, and compared with the original combination of a gear factory, we see that the contact fatigue performance of the gear with the optimal combination is much better. The research of this paper has a certain reference significance for the control of TPD, ME and LCM when machining and assembling the gears.

scholarly journals Small Caliber Bulletproof Test of Warships’ Hulls

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3848
Author(s):  
Radosław Kiciński ◽  
Andrzej Kubit
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Conditions ◽  
Finite Element Method Simulation ◽  
Material Model ◽  
Experimental Results ◽  
Material Constants ◽  
Steel Core ◽  
Calculation Results ◽  
Simulation Results

The article presents the characteristics of 1.3964 steel and the results of firing a 7.62 mm projectile with a steel core. A simplified Johnson–Cook material model for steel and projectile was used. Then, a FEM (finite element method) simulation was prepared to calibrate the material constants and boundary conditions necessary to be used in simulations of the entire hull model. It was checked how projectile modeling affects the FEM calculation results. After obtaining the simulation results consistent with the experimental results, using the model of a modern minehunter, the resistance of the ship’s hull to penetration by a small-caliber projectile was tested.

A study of azimuthal electromagnetic wave LWD based on self-adaptive hp finite element method

2018 ◽  
Vol 32 (34n36) ◽  
pp. 1840073
Author(s):  
Hui Li ◽  
Yi-Bo Jiang ◽  
Jian-Wen Cai
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Electromagnetic Wave ◽  
Real Time ◽  
Simulation Results ◽  
Peak Value ◽  
Element Method ◽  
Self Adaptive ◽  
Hp Finite Element

Azimuthal electromagnetic wave logging-while-drilling (LWD) technology can detect weak electromagnetic wave signal and realize real-time resistivity imaging. It has great values to reduce drilling cost and increase drilling rate. In this paper, self-adaptive hp finite element method (FEM) has been used to study the azimuthal resistivity LWD responses in different conditions. Numerical simulation results show that amplitude attenuation and phase shift of directional electromagnetic wave signals are closely related to induced magnetic field and azimuthal angle. The peak value and polarity of geological guidance signals can be used to distinguish reservoir interface and achieve real-time geosteering drilling. Numerical simulation results also show the accuracy of the self-adaptive hp FEM and provide physical interpretation of peak value and polarity of the geological guidance signals.

A Tunable THz Plasmonic Waveguide Based on Graphene Coated Bow-tie Nanowire with High Mode Confinement

2020 ◽  
Vol 12 ◽  
Author(s):  
Jue Wang ◽  
Tao Ma ◽  
Xu Wang ◽  
Fang Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Field ◽  
High Density ◽  
Plasmonic Waveguide ◽  
Field Distributions ◽  
Simulation Results ◽  
Photonic Circuit ◽  
Bow Tie ◽  
Element Method

Background: : A THz Plasmonic Waveguide Based on Graphene Coated Bow-tie Nanowire (TPW-GCBN) is proposed. The waveguide characteristics are investigated by using Finite Element Method (FEM). The influence of the geometric parameters on propagation constants, electric field distributions, effective mode areas, and propagation lengths are obtained numerically. The performance tunability of TPW-GCBN is also studied by adjusting the Fermi energy (FE). The simulation results show that the TPW-GCBN has better mode confinement ability. The TPW-GCBN has potential applications in high density integration of photonic circuit for the future tunable micro nano optoelectronic devices. Surface plasmon polaritons (SPPs) based waveguides have been widely used to enhance the local electric fields. It also has the capability of manipulating electromagnetic fields on the deep-subwavelength. Objective:: The waveguide characteristics of a THz Plasmonic Waveguide Based on Graphene Coated Bow-tie Nanowire (TPW-GCBN) should be investigated. The tunability of TPW-GCBN should be studied by adjusting the chemical potential (FE) which can be changed by the voltage. Method: : The mode analysis and parameter sweep in Finite Element Method (FEM) were used to simulate the TPW-GCBN for analyzing effective refractive index (neff), electric field distributions, normalized mode areas (Am), propagation length (Lp) and figure of merit (FoM). Results: : At 5 THz, Aeff of λ2/14812, Lp of ~2 μm and FoM of 25 can be achieved. The simulation results show that the TPW-GBN has good mode confinement ability and flexible tunability. Conclusion:: The TPW-GBN provides a new freedom to manipulate the graphene surface plasmons, and leads to new applications in high density integration of photonic circuit for tunable integrated optical devices.

scholarly journals Design and fabrication of a twist fixture to measure torsional stiffness of a pick up chassis

2018 ◽  
Vol 159 ◽  
pp. 02030 ◽  
Author(s):  
Ojo Kurdi ◽  
Mohd Shukri Yob ◽  
Awisqarni Haji Ishamuddin ◽  
Agus Suprihanto ◽  
Susilo Adi Widyanto ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Early Stage ◽  
Torsional Stiffness ◽  
Stage Design ◽  
Handling Performance ◽  
Simulation Results ◽  
Early Stage Design ◽  
Measured Displacement ◽  
Dial Indicator

Torsional stiffness is important parameter of chassis that affect the handling performance of chassis. Torsional stiffness can be determined using Finite Element Method (FEM) in early stage design of its. In order to validate the FEM result, experimental work needs to be done. The fixture has been design in simpler stucture, flexible for any kind of chassis and using a simple measurement’s equipment such as dial indicator and load cell. Twist fixture has been designed for measuring of torsional stiffness of TATA cab chassis indirectly. The fixture measured the deflection caused by torsion subjected to the chassis. The torsional stiffness was calculated based on measured displacement of chassis. The result of comparison shows that the experimental results in agreement with the simulation results. Therefore, the simulation results of TATA cab chassis model are valid.

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