Search results for: bender element test

Authors: A. Armin, R. Fotouhi, W. Szyszkowski

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In this paper a 3-D finite element (FE) investigation of soil-blade interaction is described. The effects of blade’s shape and rake angle are examined both numerically and experimentally. The soil is considered as an elastic-plastic granular material with non-associated Drucker-Prager material model. Contact elements with different properties are used to mimic soil-blade sliding and soil-soil cutting phenomena. A separation criterion is presented and a procedure to evaluate the forces acting on the blade is given and discussed in detail. Experimental results were derived from tests using soil bin facility and instruments at the University of Saskatchewan. During motion of the blade, load cells collect data and send them to a computer. The measured forces using load cells had noisy signals which are needed to be filtered. The FE results are compared with experimental results for verification. This technique can be used in blade shape optimization and design of more complicated blade’s shape.

Keywords: finite element analysis, experimental results, blade force, soil-blade contact modeling

Procedia PDF Downloads 299

Authors: Mahawish Masud, Muhammad Iqbal, M. U. Khan, Farooque Azam

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Manual writing of test cases from functional requirements is a time-consuming task. Such test cases are not only difficult to write but are also challenging to maintain. Test cases can be drawn from the functional requirements that are expressed in natural language. However, manual test case generation is inefficient and subject to errors.  In this paper, we have presented a systematic procedure that could automatically derive test cases from user stories. The user stories are specified in a restricted natural language using a well-defined template.  We have also presented a detailed methodology for writing our test ready user stories. Our tool “Test-o-Matic” automatically generates the test cases by processing the restricted user stories. The generated test cases are executed by using open source Selenium IDE.  We evaluate our approach on a case study, which is an open source web based application. Effectiveness of our approach is evaluated by seeding faults in the open source case study using known mutation operators.  Results show that the test case generation from restricted user stories is a viable approach for automated testing of web applications.

Keywords: automated testing, natural language, restricted user story modeling, software engineering, software testing, test case specification, transformation and automation, user story, web application testing

Procedia PDF Downloads 366

Authors: A. Nazeri, R. Ziaie Moayed, H. Ghiasinejad

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The present research has been performed to investigate the effect of base course application on load-settlement characteristics of sandy subgrade using plate load test. The main parameter investigated in this study was the subgrade reaction coefficient. The model tests were conducted in a 1.35 m long, 1 m wide, and 1 m deep steel test box of Imam Khomeini International University (IKIU Calibration Chamber). The base courses used in this research were in three different thicknesses of 15 cm, 20 cm, and 30 cm. The test results indicated that in the case of using base course over loose sandy subgrade, the values of subgrade reaction coefficient can be increased from 7  to 132 , 224 , and 396  in presence of 15 cm, 20 cm, and 30 cm base course, respectively.

Keywords: modulus of subgrade reaction, plate load test, base course, sandy subgrade

Procedia PDF Downloads 229

Authors: Hamioud Saida, Khalfallah Salah

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In this study, a spectral element method is employed to predict the free vibration of a Euler-Bernoulli beam resting on a Winkler foundation with elastically restrained ends. The formulation of the dynamic stiffness matrix has been established by solving the differential equation of motion, which was transformed to frequency domain. Non-dimensional natural frequencies and shape modes are obtained by solving the partial differential equations, numerically. Numerical comparisons and examples are performed to show the effectiveness of the SEM and to investigate the effects of various parameters, such as the springs at the boundaries and the elastic foundation parameter on the vibration frequencies. The obtained results demonstrate that the present method can also be applied to solve the more general problem of the dynamic analysis of structures with higher order precision.

Keywords: elastically supported Euler-Bernoulli beam, free-vibration, spectral element method, Winkler foundation

Procedia PDF Downloads 116

Authors: Ricardo Chaves, Carlos Vasconcelos

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Candidates to join the Naval Academy have to take a set of physical tests, which is crucial for a high level of physical fitness. Thus, the planning of physical exercises for candidates to the Naval School must take into account the improvement of their physical fitness. The aim of this study was to investigate the impact of a 6-month exercise program to improve the physical fitness of an individual who will apply for the Naval Academy. This was a non-experimental pre-post-evaluation study. The patient was male, had 18 years old, and a body mass index of 21.1 kg.m². The patient participated in a 6-month aerobic and strength exercise program (3 sessions per week, 75 minutes duration each session). Physical fitness tests were performed according to the physical fitness requirements for entry into the Naval academy (muscle strength [maximum number of lifts and maximum number of sit-ups for 1 minute]; aerobic fitness [2.4 km run and 200 m swimming test]) before (baseline) and after the exercise intervention (6 months). Regarding muscle strength, in the abdominal test, the improvements between the pre-test (39 abdominals.) and post-test (61 abdominals) were 56.4%. For elevations, there was an increase in its number by 150% between the pre-test (4 elevations) and post-test (10 elevations). With regard to aerobic fitness, in the 2.4 km race, there was an evolution of 32.0% between the pre-test (16.46 min.) and the post-test (12.42 min.). For the 200-meter swimming test, there was a negative variation of 2% between the pre-test (2.25 min.) and post-test (2.28 min). A 6-month aerobic and strength exercise program leads to a positive evolution in the muscular strength of the patient. Regarding aerobic fitness, opposite results were found, with a positive evolution in the 2.4 km running test and a negative evolution in the swimming test. In future exercise programs for the improvement of the physical fitness of candidates for the Naval Academy, more emphasis has to be done on specific swimming training.

Keywords: case study, exercise program, Naval Academy, physical fitness

Procedia PDF Downloads 72

Authors: Tae An Kim, Hyo Lim Kang, Hye Won Han, Seung Ho Han

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The drive shaft of passenger vehicle has its own function such as transmitting the engine torque from the gearbox and differential gears to the wheels. It must also compensate for all variations in angle or length resulting from manoeuvring and deflection for perfect synchronization between joints. Torsional fatigue failures occur frequently at the connection parts of the spline joints in the end of the drive shaft. In this study, the fatigue life of a drive shaft of passenger vehicle was estimated by using the finite element analysis. A commercial software of n-Code was applied under twisting load conditions, i.e. 0~134kgf•m and 0~188kgf•m, in which the shear strain range-fatigue life relationship considering Signed Shear method, Smith-Watson-Topper equation, Neuber-Hoffman Seeger method, size sensitivity factor and surface roughness effect was taken into account. The estimated fatigue life was verified by a twisting load test of the real drive shaft in a test rig. (Human Resource Training Project for Industry Matched R & D, KIAT, N036200004).

Keywords: drive shaft, fatigue life estimation, passenger vehicle, shear strain range-fatigue life relationship, torsional fatigue failure

Procedia PDF Downloads 258

Authors: Mohanad Talal Alfach

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This paper concerns the seismic behaviour of soil-piles-bridge reinforced by additional micropiles. The analysis carried out by three-dimensional finite element modelling using the FE software ABAQUS. The soil behaviour is assumed to be elastic with Rayleigh damping, while the micropiles are modeled as 3D elastic beam elements. The bridge deck slab was represented by a concentrated mass at the top of the pier column. The interaction between the added micropiles and the existing piles as well as the performance of the retrofitted soil-pile-superstructure system were investigated for different configurations of additional micropiles (number, position, inclination). Numerical simulation results show that additional micropiles constitute an efficient retrofitting solution. Analysis of results also shows that spacing between existing piles and retrofitting micropiles has little effect; while it is observed a substantial improvement (in case of weak piles/micropiles - soil interface) with reducing the inclination angle of retrofitting micropiles.

Keywords: retrofitting, seismic, finite element, micropiles, elastic

Procedia PDF Downloads 128

Authors: Rohit Khankhoje

Abstract:

The rapid evolution of software development practices has given rise to an increasing demand for efficient and effective test automation. The paper titled "Mastering Test Automation: Bridging Gaps for Seamless QA" delves into the crucial aspects of test automation, addressing the obstacles faced by organizations in achieving flawless quality assurance. The paper highlights the importance of bridging knowledge gaps within organizations, emphasizing the necessity for management to acquire a deeper comprehension of test automation scenarios, coverage, report trends, and the importance of communication. To tackle these challenges, this paper introduces innovative solutions, including the development of an automation framework that seamlessly integrates with test cases and reporting tools like TestRail and Jira. This integration facilitates the automatic recording of bugs in Jira, enhancing bug reporting and communication between manual QA and automation teams as well as TestRail have all newly added automated testcases as soon as it is part of the automation suite. The paper demonstrates how this framework empowers management by providing clear insights into ongoing automation activities, bug origins, trend analysis, and test case specifics. "Mastering Test Automation" serves as a comprehensive guide for organizations aiming to enhance their quality assurance processes through effective test automation. It not only identifies the common pitfalls and challenges but also offers practical solutions to bridge the gaps, resulting in a more streamlined and efficient QA process.

Keywords: automation framework, API integration, test automation, test management tools

Procedia PDF Downloads 53

Authors: D. K. Lee, S. M. Shin, J. H. Lee

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Topology optimization technique utilizes constant element densities as design parameters. Finally, optimal distribution contours of the material densities between voids (0) and solids (1) in design domain represent the determination of topology. It means that regions with element density values become occupied by solids in design domain, while there are only void phases in regions where no density values exist. Therefore the void regions of topology optimization results provide design information to decide appropriate depositions of web-opening in structure. Contrary to the basic objective of the topology optimization technique which is to obtain optimal topology of structures, this present study proposes a new idea that topology optimization results can be also utilized for decision of proper web-opening’s position. Numerical examples of linear elastostatic structures demonstrate efficiency of methodological design processes using topology optimization in order to determinate the proper deposition of web-openings.

Keywords: topology optimization, web-opening, structure, element density, material

Procedia PDF Downloads 457

Authors: Chandrashekhar Bhat, Dilifa Jossley Noronha, Faber A. Saldana

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Transportation of long turbine blades from one place to another is a difficult process. Hence a feasibility study of modularization of wind turbine blade was taken from structural standpoint through finite element analysis. Initially, a non-segmented blade is modeled and its structural behavior is evaluated to serve as reference. The resonant, static bending and fatigue tests are simulated in accordance with IEC61400-23 standard for comparison purpose. The non-segmented test blade is separated at suitable location based on trade off studies and the segments are joined with an innovative double strap bonded joint configuration. The adhesive joint is modeled by adopting cohesive zone modeling approach in ANSYS. The developed blade model is analyzed for its structural response through simulation. Performances of both the blades are found to be similar, which indicates that, efficient segmentation of the long blade is possible which facilitates easy transportation of the blades and on site reassembling. The location selected for segmentation and adopted joint configuration has resulted in an efficient segmented blade model which proves the methodology adopted for segmentation was quite effective. The developed segmented blade appears to be the viable alternative considering its structural response specifically in fatigue within considered assumptions.

Keywords: modularization, fatigue, cohesive zone modeling, wind turbine blade

Procedia PDF Downloads 424

Authors: Eman Alzahrani, Hala M. Abo-Dief, Ashraf T. Mohamed

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The present work is aimed at examining carbon steel oil pipelines corrosion using three natural extracts (Eruca Sativa, Rosell and Mango peels) that are used as inhibitors of different concentrations ranging from 0.05-0.1wt. %. Two sulphur compounds are used as corrosion mediums. Weight loss method was used for measuring the corrosion rate of the carbon steel specimens immersed in technical white oil at 100ºC at various time intervals in absence and presence of the two sulphur compounds. The corroded specimens are examined using the chemical wear test, scratch test and hardness test. The scratch test is carried out using scratch loads from 0.5 Kg to 2.0 Kg. The scratch width is obtained at various scratch load and test conditions. The Brinell hardness test is carried out and investigated for both corroded and inhibited specimens. The results showed that three natural extracts can be used as environmentally friendly corrosion inhibitors.

Keywords: inhibition, natural extract, oil pipelines corrosion, sulphur compounds

Procedia PDF Downloads 486

Authors: Mahmoud Lot

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In this article, we will discuss the solution of elliptic optimal control problem. First, by using the nite element method, we obtain the discrete form of the problem. The obtained discrete problem is actually a large scale constrained optimization problem. Solving this optimization problem with traditional methods is difficult and requires a lot of CPU time and memory. But split Bergman method converts the constrained problem to an unconstrained, and hence it saves time and memory requirement. Then we use the split Bregman method for solving this problem, and examples show the speed and accuracy of split Bregman methods for solving these types of problems. We also use the SQP method for solving the examples and compare with the split Bregman method.

Keywords: Split Bregman Method, optimal control with elliptic partial differential equation constraint, finite element method

Procedia PDF Downloads 133

Authors: Hyunwoo Song, Jeong-Min Lee, Yongseok Kim, Junghan Yun, Jungin Byun, Jae-Mean Koo, Chang-Sung Seok

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To avoid the damage of gas turbine blade from high-temperature, thermal barrier coating (TBC) is applied on the blade. However, it is damaged by thermal fatigue during the operation of gas turbine, and this damage lead to delamination of TBC between top coat and bond coat. The blade can be damaged after the failure of TBC, so durability evaluation of TBC should be performed. The durability of thermal barrier coating was decreased according to the increase of temperature, because thermal stress according to increase of temperature. Also, the curvature can be affect to durability of TBC, because the stress is determined by the shape of the TBC. Therefore, the effect of temperature and curvature on the stress should be evaluated. In this study, finite element analysis according to temperature and curvature were performed in the same condition of Kim et al. Finally, the stress was evaluated from the finite element analysis results according to temperature and curvature.

Keywords: curvature, finite element analysis, thermal barrier coating, thermal fatigue, temperature

Procedia PDF Downloads 546

Authors: Chen Xiong, Tong Xin, Li Hao, Xu Jin-Sheng

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Experiment and simulation researches on the structural integrity of propellant grain in solid rocket motor (SRM) with high volumetric fraction were conducted. First, by using SRM parametric modeling functions with secondary development tool Python of ABAQUS, the three dimensional parameterized modeling programs of star shaped grain, wheel shaped grain and wing cylindrical grain were accomplished. Then, the mechanical properties under different loads for star shaped grain were obtained with the application of automatically established finite element model in ABAQUS. Next, several optimization algorithms are introduced to optimize the star shaped grain, wheel shaped grain and wing cylindrical grain. After meeting the demands of burning surface changes and volumetric fraction, the optimum three dimensional shapes of grain were obtained. Finally, by means of parametric modeling functions, pressure data of SRM’s cold pressurization test was directly applied to simulation of grain in terms of mechanical performance. The results verify the reliability and practical of parameterized modeling program of SRM.

Keywords: cold pressurization test, ğarametric modeling, structural integrity, propellant grain, SRM

Procedia PDF Downloads 338

Authors: Li Xu, Yang Hong, T. Zhao Wen

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Experimental results of many RC beam-column subassemblage indicate that slippage of longitudinal beam rebar within the joint and the shear deformation of joint core have significant influence on seismic behavior of the subassemblage. However, rigid joint assumption has been generally used in the seismic response analysis of RC frames, in which two kinds of inelastic deformation of joint have been ignored. Based on OpenSees platform, ‘Super Joint Element Model’ with more detailed inelastic mechanism is used to simulate the inelastic response of joints. Two finite element models of typical RC plane frame, namely considering or ignoring the inelastic deformation of joint respectively, were established and analyzed under seven strong earthquake waves. The simulated global and local inelastic deformations of the RC plane frame is shown and discussed. The analyses also confirm the security of the earthquake-resistant frame designed according to Chinese codes.

Keywords: frame structure, beam-column joint, longitudinal bar slippage, shear deformation, nonlinear analysis

Procedia PDF Downloads 391

Authors: Isa Ahmadi, Ramin Khamedi

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In this paper, the elasto-plastic and cyclic torsion of a shaft is studied using a finite element method. The Prager kinematic hardening theory of plasticity with the Ramberg and Osgood stress-strain equation is used to evaluate the cyclic loading behavior of the shaft under the torsional loading. The material of shaft is assumed to follow the non-linear strain hardening property based on the Prager model. The finite element method with C1 continuity is developed and used for solution of the governing equations of the problem. The successive substitution iterative method is used to calculate the distribution of stresses and plastic strains in the shaft due to cyclic loads. The shear stress, effective stress, residual stress and elastic and plastic shear strain distribution are presented in the numerical results.

Keywords: cyclic loading, finite element analysis, Prager kinematic hardening model, torsion of shaft

Procedia PDF Downloads 386

Authors: Mohar Kassim, Hardy Azmir, Rahmat Sholihin Mokhtar

Abstract:

The purpose of this study is to build portable application software to determine the level of cardiovascular fitness for cadet students of the National Defence University of Malaysia (NDUM). Fitness in the context of this study refers to physical fitness, specifically the cardiovascular endurance level test battery in the form of a 2.4 km run test for UPNM cadet students. This run test will be conducted to measure, test, and evaluate the performance of UPNM cadet students. All the run test results can be recorded electronically inside the portable software and will later be able to show the level of cardiovascular fitness of every cadet student according to age and gender. This software can also calculate the body mass index (BMI). Normative survey method will be used in this study through the analysis of the 2.4 km run test results. The run test scores will be classified in interval and ratio scales. Based on the findings of this study, portable application software will produced. The software will be able to directly assist the Military Training Academy (ALK), Malaysian Armed Forces (ATM), and other relevant agencies in determining the level of cardiovascular fitness among their staff. The test can be done electronically and on portable mode. The next step to be taken is to have this application patented.

Keywords: development, software, application, portable, fitness norms, cardiovascular endurance

Procedia PDF Downloads 527

Authors: Abdur Rosyid, Mohamed El-Madany, Mohanad Alata

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Due to simplicity and low cost, rotordynamic system is often modeled by using lumped parameters. Recently, finite elements have been used to model rotordynamic system as it offers higher accuracy. However, it involves high degrees of freedom. In some applications such as control design, this requires higher cost. For this reason, various model reduction methods have been proposed. This work demonstrates the quality of model reduction of rotor-bearing-support system through substructuring. The quality of the model reduction is evaluated by comparing some first natural frequencies, modal damping ratio, critical speeds and response of both the full system and the reduced system. The simulation shows that the substructuring is proven adequate to reduce finite element rotor model in the frequency range of interest as long as the numbers and the locations of master nodes are determined appropriately. However, the reduction is less accurate in an unstable or nearly-unstable system.

Keywords: rotordynamic, finite element model, timoshenko beam, 3D solid elements, Guyan reduction method

Procedia PDF Downloads 257

Authors: Wanutchaya Duanginta, Napaporn Apiratmateekul, Tippawan Sangkaew, Sunaree Wekinhirun, Kunchit Kongros, Wanvisa Treebuphachatsakul

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Thailand has a tropical climate with an average outdoor ambient air temperature of over 30°C, which can exceed manufacturer recommendations for the storage of glucose test strips. This study monitored temperature and humidity at actual sites of five sub-district health promoting hospitals (HPH) in Phitsanulok Province for the storage of glucose test strips in refrigerated conditions. Five calibrated data loggers were placed at the actual sites for glucose test strip storage at five HPHs for 8 weeks between April and June. For the stress test, two lot numbers of glucose test strips, each with two glucose meters, were kept in a plastic box with desiccants and placed in a refrigerator with the temperature calibrated to 4°C and at room temperature (RT). Temperature and humidity in the refrigerator and at RT were measured every hour for 30 days. The mean temperature for storing test strips at the five HPHs ranged from 29°C to 33°C, and three of the five HPHs (60%) had a mean temperature above 30°C. The refrigerator temperatures were 3.8 ± 2.0°C (2.0°C to 6.5°C), and relative humidity was 51 ± 2% (42 to 54%). The maximum of blood glucose testing by glucose meters when the test strips were stored in a refrigerator were not significantly different (p > 0.05) from unstressed test strips for both glucose meters using amperometry-GDH-PQQ and amperometry-GDH-FAD principles. Opening the test strip vial daily resulted in higher variation than when refrigerated after a single-use. However, the variations were still within an acceptable range. This study concludes that glucose tested strips can be stored in plastic boxes in a refrigerator if it is well-controlled for temperature and humidity. Storage of glucose-tested strips in the refrigerator during hot and humid weather may be useful for HPHs with limited air conditioners.

Keywords: environmental stressed test, thermal stressed test, quality control, point-of-care testing

Procedia PDF Downloads 175

Authors: Juan F. P. Ramírez, Jésica A. L. Isaza, Benjamín A. Rojano

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This study proposes a novel use of a method to determine the mechanical properties of fruits by the use of the indentation tests. The method combines experimental results with a numerical finite elements model. The results presented correspond to a simplified numerical modeling of banana. The banana was assumed as one-layer material with an isotropic linear elastic mechanical behavior, the Young’s modulus found is 0.3Mpa. The method will be extended to multilayer models in further studies.

Keywords: finite element method, fruits, inverse analysis, mechanical properties

Procedia PDF Downloads 336

Authors: Mahmoud F. Awad-Allah, Mohammed Rabeih, Eman Abdel Baseer

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Soft to very soft soil deposits are widely speared in some areas of Egypt such as East Port Said, Damietta, Kafr El-Sheik, Alexandria, etc. The construction projects in these areas have faced the challenge of the presence of extended deep layers of soft and very soft clays which reach to depths of 40 to 60 m from the ground level. Stone columns are commonly used to support structures overlying soft ground soils and surcharged by embankment type loading. Therefore, this paper introduces a wide comparison numerical study between the ordinary stone columns (OSC) versus the geosynthetic encased stone columns (ESC) installed in soft clay soil deposit using finite element method (FEM). Parametric study of an embankment on soft soils reinforced with stone columns is performed using commercial computer program based on the finite element technique (PLAXIS 2D). The investigation will present the influence of the following parameters: diameter of stone columns, stiffness of geosynthetic encasement, embedded depth of stone column from ground level, and the length encasement of the stone column on the consolidation time, vertical settlement, and lateral displacement of soft clay soil formations.

Keywords: finite element method, geosynthetic, lateral displacement, settlement, soft clay

Procedia PDF Downloads 184

Authors: T. G. Pathrikar, A. D. Urhekar, M. P. Bansal

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To find out S. aureus from patient samples on the basis of coagulase test. We have evaluated slide coagulase (n=46 positive), tube coagulase (n=48 positive) and DNase test (n=44, positive) , We have isolated and identified MRSA from various clinical samples and specimens by disc diffusion method determined the incidence of MRSA 50% in patients. Found out the in vitro antimicrobial susceptibility pattern of MRSA isolates and also the MIC of MRSA of oxacillin by E-Test.

Keywords: cefoxitin disc diffusion MRSA detection, e – test, S. aureus devastating pathogen, tube coagulase confirmation

Procedia PDF Downloads 473

Authors: Subhajit Das, Nirjhar Dhang

Abstract:

Structural damage detection is a challenging work in the field of structural health monitoring (SHM). The damage detection methods mainly focused on the determination of the location and severity of the damage. Model updating is a well known method to locate and quantify the damage. In this method, an error function is defined in terms of difference between the signal measured from ‘experiment’ and signal obtained from undamaged finite element model. This error function is minimised with a proper algorithm, and the finite element model is updated accordingly to match the measured response. Thus, the damage location and severity can be identified from the updated model. In this paper, an error function is defined in terms of modal data viz. frequencies and modal assurance criteria (MAC). MAC is derived from Eigen vectors. This error function is minimized by teaching-learning-based optimization (TLBO) algorithm, and the finite element model is updated accordingly to locate and quantify the damage. Damage is introduced in the model by reduction of stiffness of the structural member. The ‘experimental’ data is simulated by the finite element modelling. The error due to experimental measurement is introduced in the synthetic ‘experimental’ data by adding random noise, which follows Gaussian distribution. The efficiency and robustness of this method are explained through three examples e.g., one truss, one beam and one frame problem. The result shows that TLBO algorithm is efficient to detect the damage location as well as the severity of damage using modal data.

Keywords: damage detection, finite element model updating, modal assurance criteria, structural health monitoring, teaching learning based optimization

Procedia PDF Downloads 198

Authors: H. A. Alguhi, W. A. Elsaigh

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This paper provides a tensile stress-strain (σ-ε) relationship for High-Strength Steel Fiber Reinforced Concrete (HSFRC). Load-deflection (P-δ) behavior of HSFRC beams tested under four-point flexural load were used with inverse analysis to calculate the tensile σ-ε relationship for various tested concrete grades (70 and 90MPa) containing 60 kg/m3 (0.76 %) of hook-end steel fibers. A first estimate of the tensile (σ-ε) relationship is obtained using RILEM TC 162-TDF and other methods available in literature, frequently used for determining tensile σ-ε relationship of Normal-Strength Concrete (NSC) Non-Linear Finite Element Analysis (NLFEA) package ABAQUS® is used to model the beam’s P-δ behavior. The results have shown that an element-size dependent tensile σ-ε relationship for HSFRC can be successfully generated and adopted for further analyzes involving HSFRC structures.

Keywords: tensile stress-strain, flexural response, high strength concrete, steel fibers, non-linear finite element analysis

Procedia PDF Downloads 342

Authors: Nikhil Gopalkrishnan, Praveen Bhaskaran, Aditya Bhargava, Gyandeep Bhumarkar

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The present paper is an attempt to perform various Non-Destructive Tests on concrete structure as NDT is gaining a wide importance in the branch of civil engineering these days. Various tests that are performed under NDT not only enable us to determine the strength of concrete structure, but also provide us in-hand information regarding the durability, in-situ properties of the concrete structure. Keeping these points in our mind, we have focused our views on performing a case study to show the comparison between the NDT test results performed on a particular concrete structure and another structure at the same site which is subjected to a continuous fire of say 48-72 hours. The mix design and concrete grade of both the structures were same before the one was affected by fire. The variations in the compressive strength, concrete quality and in-situ properties of the two structures have been discussed in this paper. NDT tests namely Ultrasonic Pulse Velocity Test, Rebound Hammer Test, Core-Cutter Test was performed at both the sites. The main objective of this research is to analyze the variations in the strength and quality of the concrete structure which is subjected to a high temperature fire and the one which isn’t exposed to it.

Keywords: core-cutter test, non-destructive test, rebound hammer test, ultrasonic pulse velocity test

Procedia PDF Downloads 328

Authors: Chor Nejmeddine, Ines Ben Omrane, Mohamed Abdelwahed

Abstract:

In this paper, we present a posteriori analysis of the discretization of the heat equation by spectral element method. We apply Euler's implicit scheme in time and spectral method in space. We propose two families of error indicators, both of which are built from the residual of the equation and we prove that they satisfy some optimal estimates. We present some numerical results which are coherent with the theoretical ones.

Keywords: heat equation, spectral elements discretization, error indicators, Euler

Procedia PDF Downloads 284

Authors: Ahmad R. Zamani, Luigi Sanguigno, Angelo R. Maligno

Abstract:

A 3D woven composite, designed for automotive applications, is studied using Abaqus Finite Element (FE) software suite. Python scripts were developed to build FE models of the woven composite in Complete Abaqus Environment (CAE). They can read TexGen or WiseTex files and automatically generate consistent meshes of the fabric and the matrix. A user menu is provided to help define parameters for the FE models, such as type and size of the elements in fabric and matrix as well as the type of matrix-fabric interaction. Node-to-node constraints were imposed to guarantee periodicity of the deformed shapes at the boundaries of the representative volume element of the composite. Tensile loads in three axes and biaxial loads in x-y directions have been applied at different Fibre Volume Fractions (FVFs). A simple damage model was implemented via an Abaqus user material (UMAT) subroutine. Existing tools for homogenization were also used, including voxel mesh generation from TexGen as well as Abaqus Micromechanics plugin. Linear relations between homogenised elastic properties and the FVFs are given. The FE models of composite exhibited balanced behaviour with respect to warp and weft directions in terms of both stiffness and strength.

Keywords: 3D woven composite (3DWC), meso-scale finite element model, homogenisation of elastic material properties, Abaqus Python scripting

Procedia PDF Downloads 119

Authors: Haitham J. M. Odeh

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This paper introduced an analysis of the effect of tunneling near pile foundations. Accomplished by three-dimensional finite element modeling. The numerical simulation is conducted using Abaqus finite element software. By examining different Tunnel-pile scenarios. The paper presents the tunnel induced pile responses, Such as pile settlement, pile internal forces, and the comments made on changing the vertical and transversal location of the tunnel related to the piles, the study contains two pile-supported structure cases, single and a group of piles. A comprehensive comparison between real case study results and numerical simulation is presented. The results of the analysis reveal the critical and safe location of tunnel construction and the positive effect of a group of piles existing instead of single piles. Also, demonstrates the changes in pile responses by changing the tunnel location.

Keywords: pile responses, single pile, group of piles, pile-tunnel interaction

Procedia PDF Downloads 118

Authors: Yeghnem Redha, Guerroudj Hicham Zakaria, Hanifi Hachemi Amar Lemiya, Meftah Sid Ahmed, Tounsi Abdelouahed, Adda Bedia El Abbas

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Creep deformation of concrete is often responsible for excessive deflection at service loads which can compromise the performance of elements within a structure. Although laboratory test may be undertaken to determine the deformation properties of concrete, these are time-consuming, often expensive and generally not a practical option. Therefore, relatively simple empirically design code models are relied to predict the creep strain. This paper reviews the accuracy of creep and shrinkage predictions of reinforced concrete (RC) shear walls structures strengthened with carbon fibre reinforced polymer (CFRP) sheets, which is characterized by a widthwise varying fibre volume fraction. This review is yielded by CEB-FIB MC90 model. The time-dependent behavior was investigated to analyze their static behavior. In the numerical formulation, the adherents and the adhesives are all modelled as shear wall elements, using the mixed finite element method. Several tests were used to dem¬onstrate the accuracy and effectiveness of the proposed method. Numerical results from the present analysis are presented to illustrate the significance of the time-dependency of the lateral displacements.

Keywords: RC shear walls strengthened, CFRP sheets, creep and shrinkage, CEB-FIP MC90 model, finite element method, static behavior

Procedia PDF Downloads 285

Authors: K. Hema Shankari, R. Thirumalaiselvi, N. V. Balasubramanian

Abstract:

The present paper addresses to the research in the area of regression testing with emphasis on automated tools as well as prioritization of test cases. The uniqueness of regression testing and its cyclic nature is pointed out. The difference in approach between industry, with business model as basis, and academia, with focus on data mining, is highlighted. Test Metrics are discussed as a prelude to our formula for prioritization; a case study is further discussed to illustrate this methodology. An industrial case study is also described in the paper, where the number of test cases is so large that they have to be grouped as Test Suites. In such situations, a genetic algorithm proposed by us can be used to reconfigure these Test Suites in each cycle of regression testing. The comparison is made between a proprietary tool and an open source tool using the above-mentioned metrics. Our approach is clarified through several tables.

Keywords: APFD metric, genetic algorithm, regression testing, RFT tool, test case prioritization, selenium tool

Procedia PDF Downloads 408