Investigation of Uncertainty Sources of Piezoresistive Silicon Based Stress Sensor

2015 ◽  
Vol 807 ◽  
pp. 45-54 ◽  
Author(s):  
Alicja Palczynska ◽  
Florian Schindler-Saefkow ◽  
Przemyslaw Gromala ◽  
Kerstin Kreyßig ◽  
Sven Rzepka ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Fem Model ◽  
Stress Sensor ◽  
Uncertainty Sources ◽  
Measurement Results ◽  
Measurement Uncertainties ◽  
Silicon Based ◽  
Sensitive Parameters ◽  
Microelectronic Package ◽  
Insight Into

The aim of this paper is to get insight into measurement uncertainties for thermomechanical measurements performed using a piezoresistive silicon-based stress sensor in a standard microelectronic package. All used sensors have the same construction, were produced in the same technological processes at the same time, yet the measurement results show significant distribution. The possible causes for this phenomenon are discussed in this paper. Additionally, Finite Element Method (FEM) model is created and validated, what enables a study of sensitive parameters influencing the measurement uncertainties.

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 Method of Measurement Representativeness Assessment for Spatial Conductometric Sensors as Applied to Investigation of Hydrodynamics in Single Phase Flows

2018 ◽  
Vol 9 (4) ◽  
pp. 314-324
Author(s):  
A. A. Barinov ◽  
V. G. Glavny ◽  
S. M. Dmitriev ◽  
M. A. Legchanov ◽  
A. V. Ryazanov ◽  
...  
Keyword(s):  
Single Phase ◽  
Wire Mesh ◽  
Electrical Circuits ◽  
Uncertainty Sources ◽  
Measurement Results ◽  
Measurement Cell ◽  
Tracer Methods ◽  
Method Of Measurement ◽  
Validation Tests ◽  
Conductivity Contrast

The well-known method of spatial conductometry is widely used for hydrodynamical investigations in the frame of validation benchmarks. The aim of the work was to develop the method of representativeness substantiation for use of the conductometric sensors in single-phase applications.The paper presents aspects of wire-mesh sensors (WMS) applications in non-uniform conductivity fields. The equivalent electrical circuits for the measurement cell and WMS are proposed and investigated. The methods of translation from measured conductance to conductivity of the water are discussed. Decomposition of the uncertainty sources and their propagation through measurements are investigated.To obtain the «cross-talk» effect of the measurements the fi model of WMS fl domain was created. The results of calculations showed the dependence of the measurement results on the conductivity contrast in the cells as well as on the size of the contrast domain. The proposed method of the measurement uncertainty estimate was applied to the real WMS and it’s measurement system. The obtained results are topical for validation tests with the use of tracer methods and WMS.

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.

Failure mechanisms in two-layer undrained slopes

2020 ◽  
Vol 57 (10) ◽  
pp. 1617-1621
Author(s):  
Shuangfeng Guo ◽  
D.V. Griffiths
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Failure Mechanism ◽  
Failure Mechanisms ◽  
Slope Angle ◽  
Strength Ratio ◽  
The Finite Element Method ◽  
Stability Analyses ◽  
Shallow Failure ◽  
Insight Into

This note presents results of stability analyses of two-layer undrained slopes by the finite element method. The study focuses on the circumstances under which either deep or shallow failure mechanisms occur, as a function of the strength ratio of the layers, slope angle, and foundation depth ratio. Improved knowledge of the location of the critical failure mechanism(s) in two-layer systems will give engineers better insight into where to focus their attention in terms or remediation or reinforcement to preserve stability.

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.

Critical indices and model of uncertainty perception for regional supply chains: insights from a Delphi-based study

2020 ◽  
Vol 25 (5) ◽  
pp. 549-564 ◽  
Author(s):  
Christopher M. Durugbo ◽  
Zainab Al-Balushi ◽  
Abdellatef Anouze ◽  
Omar Amoudi
Keyword(s):  
Supply Chain ◽  
Supply Chains ◽  
Content Type ◽  
Critical Indices ◽  
International Firms ◽  
Uncertainty Sources ◽  
Delphi Round ◽  
Delphi Exercise ◽  
Uncertainty Indices ◽  
Insight Into

Purpose The dynamic nature of uncertainty sources in regional operations represents supply chain management (SCM) imperatives to review uncertainty management frameworks on an ongoing basis with a view to identifying and prioritising critical indices of uncertainty for effective SCM. The purpose of this study is to identify the critical indices of uncertainty for regional supply chains and analyse how SCM practitioners perceive uncertainty. Design/methodology/approach This paper presents a Delphi-based study with a panel of 70 SCM experts from the Sultanate of Oman in the Gulf Cooperation Council (GCC) region. It applies three rounds of a Delphi exercise to identify, select and prioritise the critical indices of supply chain uncertainty perceived by panel experts. The thematic analysis also provides theorisations on the process for uncertainty perception and factors shaping perception. Findings A total of 39 uncertainty indices were identified from demand, supply, manufacturing, control, technology, competitive, project, transport and geological sources. The Delphi selection round captured the top 12 indices of experts. The research found an accumulative–aggregative duality that explains uncertainty perception and a cost–conformance–connection triadic set of factors underlying the perceived critical indices. Project uncertainty produced the top-ranked index in the final Delphi round. Originality/value This paper makes three main contributions. First, it offers a bottom-up based insight into supply chain uncertainty using the Delphi-based study and from a GCC perspective. Second, the research is unique in its focus on Oman and, third, it is of value for the international operations of GCC companies and for international firms with intentions of expanding, moving or outsourcing their operations to a GCC country such as Oman.

Pipeline On-Bottom Stability Analysis Based on FEM Model

2011 ◽  
Author(s):  
Yong Bai ◽  
Zhimeng Yu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Design Procedure ◽  
Element Model ◽  
The Finite Element Method ◽  
Fem Model ◽  
Engineering Software ◽  
Calculation Results ◽  
Pipeline Design ◽  
Element Method

Pipeline on-bottom stability is one of the sophisticated problems in subsea pipeline design procedure. Due to the uncertainty of the pipe-soil interaction and environment loads, including wave, current, or earthquake, etc., it is classified as the typical nonlinear problem. The Finite Element Method is introduced into pipeline engineering several years ago. More and more special engineering software such as AGA, PONDUS are available in market. However, when doing a project, some abnormal data was found when compared the DnV calculation results and AGA. In order to know the behavior of pipeline on seabed under wave and current load, finite element method – ABAQUS is introduced to do this analysis. The ABAQUS/explicit is used to simulate 600s pipeline dynamic response. The pipeline is supposed to be exposed on seabed and the selected seabed model is large enough to avoid the edge effect. ABAQUS calculation results are compared with the requirements in DnV rules to verify the validity of finite element model.

Small Wind Turbine Power Performance Testing with Uncertainty Analysis

2014 ◽  
Vol 875-877 ◽  
pp. 1944-1948
Author(s):  
Wen Lei Bai ◽  
Byun Gik Chang ◽  
Gerald Chen ◽  
Ken Starcher ◽  
David Carr ◽  
...  
Keyword(s):  
Wind Speed ◽  
Uncertainty Analysis ◽  
Wind Turbine ◽  
Performance Testing ◽  
Air Pressure ◽  
Power Performance ◽  
Small Wind Turbine ◽  
Uncertainty Sources ◽  
Measurement Uncertainties

Wind turbine power performance testing consists of power, temperature, air pressure and wind speed measurements collected for this study during which measuring uncertainties are involved. Due to the measurement uncertainties, the results of power performance testing are affected; therefore, it is necessary to consider the measurement uncertainties for evaluating the accuracy of turbine testing. For this purpose of this study, uncertainty analysis for one 5kW wind turbine power performance testing was conducted. The results of uncertainty analysis indicated that the uncertainty negatively affected the validity of conclusions drawn from power performance testing, and the uncertainty sources are various in different wind speed bins.

Analysis of ZDDP Films on Sticking Defects by FEM during Hot Rolling of Ferritic Stainless Steel Strips

2016 ◽  
Vol 846 ◽  
pp. 96-101
Author(s):  
Liang Hao ◽  
Zheng Yi Jiang ◽  
Dian Yao Gong ◽  
Dong Bin Wei ◽  
Xia Wei Cheng ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Hot Rolling ◽  
Steel Strip ◽  
Crack Size ◽  
Surface Characterisation ◽  
Fem Model ◽  
Steel Strips ◽  
Simulation Results

The aim of this study is to understand the effect of zinc dialkyl dithio phosphate (ZDDP) films on sticking defects during the hot rolling of ferritic stainless steel strips. The surface characterisation and crack propagation are very important for the sticking defects of ferritic stainless steel strip. A finite element method (FEM) model is constructed with different crack size ratios, in which the profile of the strip roughness and ZDDP films are taken into consideration. Simulation results show that the widths of cracks tend to be reduced with the introduction of ZDDP films, improving the sticking defects, which is confirmed by the hot rolling trials.

Research on the Influence of Web’s Shear Deformation on the Deflection of Composite Girder Bridge with Corrugated Steel Webs in Construction

2012 ◽  
Vol 178-181 ◽  
pp. 2135-2139
Author(s):  
Shang Min Zheng ◽  
Bing Wen Yang ◽  
Shui Wan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Shear Deformation ◽  
Finite Element Method Analysis ◽  
Composite Girder ◽  
Measurement Results ◽  
Girder Bridge ◽  
Method Analysis ◽  
Load Conditions ◽  
Practical Measurement

In order to research the influence of web’s shear deformation on the deflection of composite girder bridge with corrugated steel webs in construction, the deflection calculation formulae considering shear deformation were deduced, which was to analyze the background engineering of Chuhe bridge deflection in different load conditions when it was in the maximum cantilever state. Finite element method analysis shows that the calculation formulae are credible and applicable, and also comparative study was done with practical measurement. Results show that the proportion of main deflection caused by shear deformation of web may reach 30% ~ 40%, and the deflection caused by shear deformation needs to be considered in the process of construction monitering.

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