Finite Element Analysis (Engineering)

This paper presents a numerical analysis of a short circular hollow column using ABAQUS software. Circular hollow sections have high structural efficiency due to lack of major or minor axes. Such sections are also effective in areas with limited spaces.This paper provides an examination of their performance under axial loading using numerical analysis

In this paper, the complementary role of Finite Element Analysis (FEA) and Modal Analysis is studied using ANSYS Mechanical APDL. Primarily, two models (2D and 3D) of the flywheel are designed. Then, Finite Element (FE) static-stress analysis of the model was carried out, and it is found that the maximum von Mises stress (403 MPa) on the flywheel is lower than the yield stress (850 MPa) level, i.e. the design of the flywheel is safe. Afterwards, the Modal Analysis of the 3D model is carried out and six mode shapes are obtained at six different natural frequencies. Furthermore, Campbell diagram is plotted and two natural frequencies are identified. Moreover, mode shapes are plotted at the two critical speeds corresponding to their respective damped natural frequencies. The mode shapes are found to be stable, and therefore it can be remarked that the flywheel model is safe to operate within 12000 rpm. Finally, the performance of ANSYS models is determined by comparing analytical solut...

Due to complex loading and chemical conditions of the human body, the artificial replacements of the body organs demand materials with superior characteristics. Therefore, recently using composite materials have gained a lot of popularity for this purpose. As a special case of the composite materials, functionally graded materials (FGMs) exhibit very interesting behavior that makes them a very suitable candidate where this study is aimed to examine the performance of femoral prostheses made of a FGM. The internal and external layers of the prostheses were composed of stainless steel and hydroxyapatite, respectively. The finite element method was used to compute the strain energy density in the proximal metaphysis of the bone, von Mises stress over the femoral prostheses, and maximum and minimum principal stress developed in the bone. The results revealed dependency of the strain energy density, interface stresses, and implanted femur component stresses on the gradient index and geometrical properties of the prostheses. Moreover, among the geometrical factors, profile and proximal cross-section were the key factors to alter strain energy density, whereas the distal cross-section effect was minor. Besides, changes in interface stresses were related to all geometrical properties of prostheses. However, stress changes in prosthesis and bone were less evident under the influence of prosthesis geometrical properties, while strains in bone showed a significant dependency to the gradient index and geometrical properties of the prosthesis.

In this paper high speed turning and milling models are considered and chip formation and cutting forces are investigated. For the simulation the Finite Element Modeling software Third Wave Systems AdvantEdge is employed and the cutting forces results as well as the morphology of the chip are compared with the results of experiments conducted with CNC machine tools. For the experimental work the principles for design of experiment were used in order to minimize the required amount of experiments and obtain useful results at the same time. All parameters and cutting conditions were chosen to be close to the common industrial ones, with the material of the workpiece being C45 steel and the tools being coated carbides. Although published work on FEM simulations on high speed machining exist, this paper provides validated 3D models that cover the cases of precision high speed turning and high speed milling. The validation of the numerical data with the experimental ones show a good agre...

Two original numerical techniques are developed for the finite element (FE) transient analysis of induction and permanent magnet motors operating in demanding aerospace applications. The first technique is the electromagnetic and thermal analysis weak coupling using a multiple slices 2D FE model. The advantage of the specific technique is the representation of complex actuator geometries including skewed magnets and winding ends, by using a low computational cost 2D model while taking into consideration temperature dependent material attributes. The second technique consists in the development of properly defined boundary conditions for the emulation of the cooling housing of actuators. Those boundary conditions are applied at the outer surface of the actuators in contact with the housing and eliminate the need of modeling complex 3D geometries of highly integrated actuator housings.

1M. Tech student, Civil-Structures, Maharashtra Institute of TechnologyWPU, Pune, M.H. India 2HOD, Civil-Structures, Maharashtra Institute of Technology-WPU, Pune, M.H. India ---------------------------------------------------------------------***-------------------------------------------------------------------ABSTRACT: Beam column joints in concrete framed structure have been identified as critical member for transferring forces and bending moments between beams and columns. The change of moments in beam and columns across the joint region, under loadings, induces high shear force and stresses as compared with other adjacent members. The shear failure caused is often brittle in nature which is not an acceptable structural performance. Retrofitting enhances the moment carrying capacity of joint. Often beam column joints need to be strengthened. Author proposes use of ferrocement for retrofitting as wrapping technique, cost effective alternative to costly FRP wrapping technique. In...

Degradation of silane coupling layers by water ingress in computer-aided design/computer-aided manufacturing (CAD/CAM) of resin composites has been reported qualitatively. In this study, we quantitatively evaluated how water absorption of CAD/CAM resin composites affects the silane coupling layer by in vitro and in silico methods. Methods: A Katana Avencia block (KAB) and an experimental matrix block composed of only a matrix resin were used to evaluate the effect of water immersion for seven days on the elastic modulus. X-ray photoelectron spectroscopy (XPS) with fluorine-labeling of the KAB was performed to evaluate the atomic percentage of F1s, which represents the hydrolysis amount by water immersion. In silico analysis of the three-dimensional model of the KAB was performed to determine the coupling ratios before and after water immersion. Results: The elastic modulus of the KAB was 8.2 GPa before and 6.9 GPa after immersion in water. The atomic percentages of F1s in the after-and before-immersion groups were 14.31% and 11.52%, respectively, suggesting that hydrolysis of the silane coupling layer occurred during water immersion. From in silico analysis of the three-dimensional model of the KAB, the coupling ratio was predicted to be 78.2% before water immersion. After water immersion, the coupling ratio was predicted to be 68.4%. Conclusion: The in vitro and in silico approaches established in this study were able to predict the silane coupling ratios of CAD/CAM resin composites, and they showed that the silane coupling ratio decreased by water absorption.

The purpose of this work is to discuss the tulip contact behavior during mechanical and electrical simulations in a Finite Element Method (FEM) environment using ANSYS and COMSOL software. During the simulations, the full contact movement was analyzed. During the contact movement, the individual behavior of the contact components was taken into consideration. The motion simulation was carried out at different velocities and forces acting on the contact. The obtained results were compared to each other and discussed. Relatively, the angles of the contact surfaces to each other were also changed, which meant that we could conduct a more in-depth analysis. The other approach of simulation research was a field analysis of physical phenomena occurring in the tulip contact. This analysis was performed in COMSOL Multiphysics. Parametric analysis allowed an observation of the electric field in the tulip contact at different contact distances with respect to each other. This work is importan...

Transformer design optimization is determined by minimizing the transformer cost taking into consideration constraints imposed both by international specifications and customer needs. The main purpose of this work is the development and validation of an optimization technique based on a parallel mixed integer nonlinear programming methodology in conjunction with the finite element method, in order to reach a global optimum design of wound core power transformers. The proposed optimization methodology has been implemented into software able to provide a global feasible solution for every given set of initial values for the design variables, rendering it suitable for application in the industrial transformer design environment.

Abstract Sauropod dinosaurs were the largest terrestrial
herbivores and pushed at the limits of vertebrate biomechanics
and physiology. Sauropods exhibit high craniodental
diversity in ecosystems where numerous species coexisted,
leading to the hypothesis that this biodiversity is
linked to niche subdivision driven by ecological specialisation.
Here, we quantitatively investigate feeding behaviour
hypotheses for the iconic sauropod Diplodocus. Biomechanical
modelling, using finite element analysis, was used to
examine the performance of the Diplodocus skull. Three
feeding behaviours were modelled: muscle-driven static biting,
branch stripping and bark stripping. The skull was found to be
‘over engineered’ for static biting, overall experiencing low
stress with only the dentition enduring high stress. When
branch stripping, the skull, similarly, is under low stress, with
little appreciable difference between those models. When simulated for bark stripping, the skull experiences far greater
stresses, especially in the teeth and at the jaw joint. Therefore,
we refute the bark-stripping hypothesis, while the hypotheses
of branch stripping and/or precision biting are both
consistent with our findings, showing that branch stripping
is a biomechanically plausible feeding behaviour
for diplodocids. Interestingly, in all simulations, peak
stress is observed in the premaxillary–maxillary ‘lateral
plates’, supporting the hypothesis that these structures
evolved to dissipate stress induced while feeding. These
results lead us to conclude that the aberrant craniodental
form of Diplodocus was adapted for food procurement
rather than resisting high bite forces.

This paper investigates the dynamic characteristics of pulley systems with different numbers of bolt holes. Models with four, six and eight bolt holes were chosen for the pulley. Three sets of cyclic pressure were applied to the pulley system to resemble the different running revolutions of an engine. The study investigates the effect of the number of holes on the system’s stiffness and natural frequency. Finite element models were used to simulate the obtained deformations, stresses and frequency response function (FRF) for pulley models comprising four, six and eight bolt holes under different cyclic pressures. The results show that the stiffness and natural frequency increased with increasing the number of the bolt holes. This in turn, reduced the resulted deformations and stresses.
Recommended Citation
Asker, Haval Kamal and Dawood, Thaker Saleh (2020) "On The Dynamic Behaviour of Automobile Pulleys Under Cyclic Loading," Karbala International Journal of Modern Science: Vol. 6 : Iss. 2 , Article 12.
Available at: https://doi.org/10.33640/2405-609X.1603

Engineering codes are a key method to guide designs to safe and reliable outcomes. Many such codes have prescribed calculations where the user provides specific inputs in a series of calculations, often using charts or tables, to get specific outputs. The design margins, units, and underlying theory are not always apparent. Engineering codes may not be suitable for reverse engineering an incident or providing a failure prediction. This article examines a criminal negligence case in which an initial forensic analysis incorrectly applied the ASME Pressure Vessel Code to use Finite Element Analysis (FEA) of a failed pressure vessel section. The flaws in the original analysis were revealed by applying reverse engineering using conventional stress calculations and understanding basic material science. This emphasizes the need to understand the underlying theories with both engineering codes and numerical modeling. Subsequent FEA provided an accurate analysis report that was successfully used in court. These same methods can be applied to many other engineering codes and standards. "Although most people do not realize it, standards and the methods used to assess conformity to standards are absolutely critical. They are essential components of our nation's technology infrastructure-vital to industry and commerce, crucial to the health and safety of Ameri-cans, and basic to the nation's economic performance 1 ."

In this paper, both flap-wise and edge-wise natural frequencies of vibration of a variable blade length wind turbine are calculated.  A stepped beam with two portions has been used to approximate the blade. The two portions of the blade have been approximated by a hollow beam and a solid beam with rectangular cross section. As the outboard portion of the blade can be slid in and out of the inboard portion, ten different configurations of the stepped beam have been investigated. A MATLAB program has been developed for a finite element analysis of a one dimensional model of the stepped beam. Subsequently a three dimensional model of the stepped beam has been developed in the finite element program Unigraphics NX4. The results found using the MATLAB program have been compared with those found with NX4 and satisfactory agreement between these results has been found. Additionally, the influence of varying the blade length on the natural frequencies has been investigated.

A generalized macroscopic representation of electrical steels used in transformer manufacturing industry is developed. The proposed representation is specifically formulated for integration in the finite element method. Usage of the specific technique enables the accurate evaluation of electromagnetic field distribution of transformer cores under heavily saturated conditions. Advantages over conventional techniques include numerical stability, numerical accuracy, and reduction of iterations of the Newton–Raphson method.

Increase in use of power electronics in power system addressed power quality problems. Converters are widely used in industrial area for different application. They are non-linear devices and degrade power quality of system. In this paper, 12 – pulse ac – dc power supply is taken as non-linear load example. Power supply, here discuss is use in low voltage, high dc current application. High dc current is generated by connecting four M3 converters in parallel. Phase-shifting transformer is also introduce for require phase displacement. Converter can affect power quality in terms of inject harmonics and decrease power factor. It can be used as dynamic load; therefore, it is necessary to evaluate active and reactive power for different loading condition. This paper represents assessment of power quality for such system.

Purpose: Fractographic analysis has been used to investigate the fracture behavior of Computer-aided design/ computer-aided manufacturing (CAD/CAM) composite crowns by subjecting them to compression tests. However , it is difficult to investigate details of the fracture, including its initiation and propagation, using in vitro tests. The aim of this study was to determine the fracture origins and the order of crack initiation of CAD/CAM composite crowns using in silico nonlinear dynamic finite element analysis (FEA). Material and methods: The following materials were used: Cerasmart (CS), Katana Avencia Block (KA), and Shofu Block HC (HC) as CAD/CAM crowns, Panavia SA Cement Plus (SA) as a luting material, and Clearfil DC Core Plus (DC) as an abutment. The elastic moduli and fracture strain of each material were obtained from the stress-strain curve of in vitro three-point bending tests. The fracture origins and order of crack initiation of the materials were determined by in silico nonlinear dynamic compression analysis. Load-displacement curves were statistically compared with the results of the in vitro compression tests (Pearson's correlation test, α = 0.05). Results: The nonlinear dynamic FEA demonstrated that crack initiation was primarily observed near the lingual side of the CAD/CAM crowns and immediately propagated to the central fossa. The models were fractured following the in vitro fracture strains, showing the same order for the products tested (CS/KA/HC, SA, and DC). Load-displacement curves with the use of CS, KA, and HC were significantly correlated to the corresponding in vitro compression tests results (CS: r = 0.985, p < 0.05, KA: r = 0.987, p < 0.05, and HC: r = 0.997, p < 0.05). Conclusions: The in silico model established in this study clarified the crack initiation of the CAD/CAM composite crowns and the order of crack initiation among the investigated products, suggesting that the present approach is useful for analyzing the fracture behavior of CAD/CAM composite crowns in detail.

Damages of adjacent bridge structures due to relative responses such as poundings and unseating have been observed in many earthquakes. The isolators in bridge structures are effective in mitigating the induced seismic forces, however, the deck displacement becomes excessively large when subjected to a ground motion with unexpected characteristics, therefore increase the possibility of pounding; contribute to the unseating of bridge decks and subsequent collapse. An analytical model of expansion joints that takes account of the interaction between adjacent segments of the bridge deck and the effect of impact and restrainers is developed for nonlinear time history analysis. The numerical results show that pounding between adjacent bridge segments could amplify the relative displacement, resulting in the requirement of a longer seat width to support the deck. Pounding results in a transfer of large lateral force from a deck to the other, consequently, results in significant changes in the global response of the participating structural systems. So it is effective to provide a shock absorber between adjacent decks for the mitigation of pounding effect.

Convolving the output of Discontinuous Galerkin computations with symmetric Smoothness-Increasing Accuracy-Conserving (SIAC) filters can improve both smoothness and accuracy. To extend convolution to the boundaries, several one-sided spline filters have recently been developed. This paper interprets these filters as instances of a general class of position-dependent (PSIAC) spline filters that can have non-uniform knot sequences and skip B-splines of the sequence. PSIAC filters with rational knot sequences have rational coefficients. For prototype knot sequences , such as integer sequences that may have repeated entries, PSIAC filters can be expressed in symbolic form. Based on the insight that filters for shifted or scaled knot sequences are easily derived by non-uniform scaling of one prototype filter, a single filter can be re-used in different locations and at different scales. Computing a value of the convolution then simplifies to forming a scalar product of a short vector with the local output data. Restating one-sided filters in this form improves both stability and efficiency compared to their original formulation via numerical integration. PSIAC filtering is demonstrated for several established and one new boundary filter.

In this paper a robust three-dimensional (3D) finite element (FE) anisotropy model is introduced based on a particular scalar potential formulation. The specific 3D FE model is suitable for the accurate evaluation of the peak flux density distribution and no load loss of one-phase and three-phase wound core distribution transformers. The accuracy of the proposed 3D FE anisotropy model is validated by local flux density and no load loss measurements.

It is currently impossible to control irrigation at the level of a single plant. Even with drip irrigation, in which emitters could conceivably be placed on a plant-by-plant basis, there is no way to control the amount of water emitted according to the needs of the individual plants. If such a capability were practically available on farms, the result would be a step change in precision agriculture, such that the water input for every plant in a farm (or field) could be optimized. Therefore, we are exploring the possibility of developing a microfluidic system that could be controlled, capillary by capillary, to deliver the needed amount of water to individual plants in a large field. The principal aim is to show proof of concept by building and testing a prototype to produce data suggestive of the potential for multiple individually controllable microfluidic ports along a pressurized tube of water. Hence, in this study we perform experiments using a thermally actuated microvalve for...

Power transformer analysis and design focusing on the equivalent circuit parameter evaluation by magnetic field numerical calculation is presented. The proposed method adopts a particular reduced scalar potential formulation enabling 3D magnetostatic problem solution. This method, necessitating no source field calculation, in conjunction with a mixed finite element-boundary element technique, results in a very efficient 3D numerical model for power transformer design office use. Computed results are validated through measurements. Such a methodology is very promising for investigation concerning losses and short circuit voltage variations with the main geometrical parameters.

There have been numerous publications on unreinforced masonry construction in the literature; however, there is a lack of publications on the condition assessment of existing unreinforced masonry façades for disturbances due to nearby subway construction. To fill this gap, this paper presents a study in which a 5-story historical building with unreinforced masonry façade experiences inward and outward deformations perpendicular to the plane of wall due to nearby subway construction. The performance of the unreinforced masonry façade is examined under wind load combinations. For this, a finite-element (FE) model is built in ANSYS software to conduct a stress analysis of the brick façade. The results revealed that the tensile stresses exceeded the tensile stress limit at several locations; therefore, a structural remediation is required. A structural retrofit is proposed to tie the façade wall to the floor diaphragms with steel anchor rods at specific stories. Another FE model is built to represent the remedies proposed for stabilizing the façade wall. The results show that all stresses are within the limits, indicating that the structural solution for the remediation is appropriate. As a result of this study, the proposed remediation was implemented at the building, and the structure has been in good structural condition without any complaints, even after the subway construction was completed and the subway line was in operation.

Information on the behaviour of equipment will guide in proper design of such equipment which will prevent or minimize the impact of earthquake on such equipment, therefore, this research investigated the impact of Response Spectrum (RS) on the deformation of Pressure Vessel (PV) for a location prone to earthquake attack. The designed PV natural frequency was computed manually using the guideline of ASCE 7-10 and simulated using ANSYS structural which was finally used for analysis of PV and modified PV with inclusión of rotational velocity (PV-RV) subject to the values obtained for Total Deformation (TD), Directional Deformation (DD) and Direction Acceleration (DA) respectively for simulated earthquake environment using Response Spectrum (RS). The results obtained showed that ANSYS simulation of natural frequency of PV was close to the manually computed one with error of 9% and the response of PV and PV-RV to RS are different and opposite for both DA and DD respectively.

Conservation efforts for the 40-foot-long H.L. Hunley submarine (1864) have now reached a point that requires mechanical rotation of the vessel’s hull. This new course of action has raised a number of important questions regarding the submarine’s structural integrity. In response, project scientists have developed a finite element numerical model of the hull in its current state in an attempt to answer these questions. Data for the numerical model was obtained from archaeological documentation, as well as analytical data from non-destructive evaluation and metallurgical studies. Although finite element analysis is commonly used for structural analysis in many fields of engineering, its application to a historical structure such as the H.L. Hunley brings significant challenges. In particular, the exact degree of deterioration and the heterogeneous nature of the corrosion create uncertainty in identifying material properties. The finite element analysis provides conservators with a theoretical framework to assess the impact that rotation of the hull’s original orientation might have on its overall structural integrity and provides a basis for conservation-related decisions.

En el presente trabajo, se realiza un análisis teórico de los cálculos para determinar la velocidad de salida de un flujo permanente incompresible (agua), en una tobera cónica, usada como elemento de un sistema hidráulico de riego de un invernadero. Para determinar la velocidad de salida se emplea el método analítico de la ecuación de continuidad y un análisis por elemento finito (FEA), utilizando el software SOLIDWORKS y su complemento Flow Simulation versión 2016.

This thesis investigates the use of a Helical Steel Pile (HSP), as an in-ground heat exchanger for a Ground-Source Heat Pump (GSHP) system. A multi-layered soil conductivity dataset was created to quantify thermal performance across a variety of climate and soil conditions. Geometric features of the HSP were optimized using parametric sweeps, and the capacity of the pile to supply a building load was characterized for a variety of inlet fluid temperatures, seasons, and locations. Transient simulations of the pile characterized its ability to supply three different types of building load sets across a year. Finally, 40-year simulations showed the potential for the HSP to provide heating to buildings in a northern region while also mitigating the thawing of permafrost from climate change. The results indicate a potential to provide sustainable thermal energy to remote communities while delaying the predicted thawing of permafrost locally by up to 75 years.

Polydimethylsiloxane (PDMS) is a soft polymer that is primarily used for soft lithography (e.g., microfluidics and labon-chip devices) and also has wide range of applications, such as for thermomechanical actuators. The unique material properties of PDMS (such as the low values of Young's modulus) renders it to be an attractive material for applications where large range of deformations can be achieved with small variations in the actuating pressure (or actuating forces) thus providing good mechanical advantage. PDMS has been reported in the literature for microfabricating and testing thermally actuated microvalves (for microfluidics applications). These microvalves involve the thermal expansion of a fluid resulting in the deformation of a flexible PDMS membrane. Accurate numerical modeling of such thermo-mechanical actuators made from PDMS necessitates the knowledge of the temperature dependent mechanical properties of PDMS (such as Young's modulus) which is currently lacking in the literature. In this study large deformations were obtained for a thin flexible PDMS membrane (with a square footprint of 7.2 mm and thickness of 200 microns) that was microfabricated on the top of a hermetically sealed cavity (that was 3 mm deep) by subjecting the membrane to thermo-pneumatic pressure arising from the thermal expansion of air trapped in the hermetically sealed cavity and heated from below. This enabled the experimental determination of maximum displacement of the membrane as a function of actuating temperature and therefore the estimation of the temperaturedependent mechanical properties (e.g., Young's Modulus and Poisson's ratio) using parametric simulations using the finite element method (FEM) and based on linear elastic assumption for the deformation of PDMS. Using digital images of the convex shape of the deformed PDMS membrane the maximum deformation was measured as a function of temperature under steady state conditions. Computational Fluid Dynamics (CFD) based commercial solver (Ansys™ 2019R1®) was used to estimate the air pressure inside the hermetically sealed chamber as a function of temperature under steady state conditions (which was verified by analytical calculations). The values of pressure (obtained from CFD simulations) was used as the boundary condition in the FEM model (Ansys™ 2019R1®) for a fixed value of the Young's Modulus and Poisson's ratio to estimate the maximum deformation of the PDMS membrane. By parametric variation of the Young's Modulus and Poisson's ratio (for a particular operating temperature) the actual values were determined based on the computational result that matched the experimental data. The results show that the material

A finite Element method approach has been developed for structural analysis of various industrial products. It helps to analyze and solve the problem of structural displacement due to various internal and external forces. And it also helps in the calculation stresses and strains. This method can be applied to typical MEMS structures such as beam, plate and other complex structures. The theoretical analysis of the finite element method is well established in the case of the triangular or tetrahedral meshes. In this case we use 4-node rectangular mesh, for the analysis of a flat plate of uniform thickness with the help of Matlab. Our theory supported by the some numerical experiments, which are taken from various engineering application, ranging from elasticity and in other forces and stress analysis.

Industrial archaeology and the preservation of industrial heritage is a topic of increasing interest. This field includes numerous remains of the industrial past, such as manufacturing and mining sites, as well as power and transportation infrastructure, or historical places related to industry, including worker housing and warehouses, among others. The present paper presents the structural system of the loading ladder in Megalo Livadi of Serifos and a proposal of its restoration. The loading ladder has a great value as a landmark situated at the listed mining monumental site of Mega Livadi. The structure consists of a bridge-like steel truss structure overhanging one support; one support is on the coast, while the other is a strong stone pillar founded at the bottom of the sea. Due to the complex nature of the problem, static, seismic, hydraulic and geotechnical studies were combined for the final assessment. With the purpose of rehabilitating the conveyor as an accessible monument, further analyses were executed, based on the least possible interventions, respecting its architectural and historical value.

This study is aimed at evaluating the biomechanical behavior of feldspathic versus alumina porcelain veneers. A 3D numerical model of a maxillary central incisor, with the periodontal ligament (PDL) and the alveolar bone was generated. Such model was made up of four main volumes: dentin, enamel, cement layer and veneer. Incisors restored with alumina and feldspathic porcelain veneers were compared with a natural sound tooth (control). Enamel, cementum, cancellous and cortical bone were considered as isotropic elastic materials; on the contrary, the tubular structure of dentin was designed as elastic orthotropic. The nonlinear visco-elatic behavior of the PDL was considered. The veneer volumes were coupled with alumina and feldspathic porcelain mechanical properties. The adhesive layers were modeled in the FE environment using spring elements. A 50N load applied at 60° angle with tooth longitudinal axis was applied and validated. Compressive stresses were concentrated on the external surface of the buccal side of the veneer close to the incisal margin; such phenomenon was more evident in the presence of alumina. Tensile stresses were negligible when compared to compressive ones. Alumina and feldspathic ceramic were characterized by a different biomechanical behavior in terms of elastic deformations and stress distributions. The ultimate strength of both materials was not overcome in the performed analysis. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009

A detailed study was carried out on crankshafts used in two wheeler made from C45 (EN 8/AISI 1042) steel. Undesirable noise was heard in crankshaft when the engine is in running. This was stated as failure of crankshaft. Material has been peeled off and seemed to be scraped at the central portion of the crankpin.  It was the bearing seating place where oil hole also provided. Under analysis the crankpin was identified as tempered. Chemical composition, micro-hardness and microstructure were studied and compared with the specified properties of the crankpin material. Reason for failure is identified as wear due to lower hardness, improper lubrication and high operating oil temperature.

the pattern of partial discharge (PD) occurrence at a defect site within a solid dielectric material is influenced by the conditions of the defect site. This is because the defect conditions, mainly its size and location determine the electric field distributions at the defect site which influence the patterns of PD occurrence. A model for a spherical cavity within a homogeneous dielectric material has been developed by using Finite Element Analysis (FEA) software. the model is used to study the influence of different conditions of the cavity on the electric field distribution in the cavity and the PD activity. in addition, experimental measurements of PD in spherical cavities of different size within a dielectric material have been undertaken. the obtained results show that PD activity depends on the size of the cavity within the dielectric material. © 2009 IEEE.

http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5252384

Over the years, wind loading codes has been a crucial tool in determining design wind loads on buildings. Due to the limitations of these codes especially in height, wind tunnel testing is recommended as the best approach in predicting wind flow around buildings but carrying out wind tunnel testing in the preliminary as well as final design stage of a project has proven uneconomical and incurs additional cost to the client. In response to this, CFD which is a virtual form of wind tunnel testing was developed. From immersive researches and experiments carried out by previous researchers, best practice guidelines have been given on the use of CFD in predicting wind flow around buildings. This paper compares the results of a case study application of computational fluid dynamics simulation in determining the wind loads on the facade of a typical 48.8m high-rise building to the predictions given in British wind Standards BS6399-2:1997, using wind speed data of Lagos state Nigeria. From the results, it was shown that the latter can offer considerable saving and highlight problem areas overlooked by the British code of practice (BS6399-2:1997).

World experiences reveal that catastrophic floods are posing a serious threat that comes not only from them as extreme events but also as the result of adaptation measures uncertainty, (i.e. dikes). In particularly old dikes constructed earliest at the north part of Albania, during the last floods demonstrated the high uncertainty and weak spots. In this paper, the significance of the seepage investigation and stability analysis are discussed. As a case study, parts of new dikes constructed last years along the Buna River located in north part of Albania are investigated. Filling materials for these dikes are represented mostly from silt and clay. Finite element method is used to perform seepage analysis while general limit equilibrium method is used to perform slope stability analysis. Both, seepage and slope stability analyses are done for three different scenarios: steady state, rapid filling, and rapid drawdown. Finally, it is concluded that silt-clay material used in these dike structure is posing serious uncertainty during seepage phenomenon by threatening the stability of entire dike structure especially during the transient condition (rapid filling and drawdown).

Joining steel plates and aluminum plates by means of using Fe/Al structural (Triclad) transition joints has been well-received in the shipbuilding industry, but is rarely applied in other industries. In this work, 12.7 mm thick plates of advanced high-strength steel and AA 6061 alloy were successfully joined by using hybrid laser-arc welding with the help of Triclad transition joints. The parameters were optimized for welding dissimilar steels (A516 to advanced high-strength steel) and welding dissimilar aluminum alloys (AA 5456 to AA 6061). The optimization controlled the total heat input and kept the Al/Fe interface
of the Triclad transition joint below the maximum allowable temperature of 315.56 C in order to minimize the growth of brittle intermetallic phases and retain the mechanical properties of the Triclad transition joint. A finite element model was developed to study the temperature evolution at the Triclad interface and the heat distribution along with the welded structure. A ‘‘4:1’’ ratio was used between the width
of the Triclad transition joint and the thickness of the webs. This ratio improved the load-bearing property of the Triclad transition joint and compensated for the microcracks and brittle Al-rich intermetallic
phases observed at the Triclad interface. Tensile strength of 220 MPa was achieved at the welded structure. The fracture occurred at the heat-affected zone of the AA 5456-to-AA 6061 weld.

Confined masonry (CM) is an effective building construction technology for low-tech construction in seismic-prone regions. This paper focuses on developing a numerical model to study the in-plane seismic behaviour of CM wall. A half-scaled CM wall specimen is designed based on Mexican practice and tested under a combination of vertical load and in-plane cyclic load up to failure. Based on that a three dimensional (3D) finite element macro-modelling technique is developed using the commercial software package ABAQUS, where the masonry panel, RC tie-frame, and reinforcements are discretely modelled. The strength and stiffness degradation of masonry and concrete is defined using Concrete Damaged Plasticity (CDP), which is a damaged plasticity-based continuum constitutive model. All the input data in the numerical model are based on experimental test results and data obtained from past literature or inverse fitting, with justification. From the analysis, it is observed that the numerica...

Considering corrosion rate during the remaining life assessment of aging pipelines is fundamental to calculate the interval between two consecutive inspections. A total of 798 internal and external corrosion defects have been detected, using the Magnetic Flux Leakage intelligent inspection tool, over 48 km of a pipeline length located in the west region of Algeria. The statistical analysis has shown that there is a strong correlation between the corrosion defect length and the corrosion defect circumferential width, with a significant correlation coefficient equal to 82.87%. A probabilistic methodology is presented for the assessment of the remaining life of a corroded pipeline transporting gas, and a finite element method (FEM) was used to assess the pipeline failure pressure. The numerical FEM modeling results were compared with the commonly used codes-models for calculating limit pressure to establish a more realistic and accurate engineering model. The reliability analysis of an API 5L X60 steel made Algerian natural gas pipeline, in service for thirty years, and exposed to active corrosion attack, is presented. The sensitivity analysis of the basic random variables within the nonlinear limit state function was carried out to bring out the relative contribution of each variable affecting the remaining life of corroded pipelines. The reliability analysis is carried out by using Breitung's formula, based on the second-order reliability method (SORM). The reliability assessment of the corroded pipeline is based on the usage of the notched failure assessment diagram (NFAD), different codes for the calculation of the failure pressure, and the numerical results using the finite element analyses (FEA) software ANSYS.