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Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents an experimental study on the mechanical behavior of buried pipes subjected to thermal load cycles. Firstly, stresses and deformations are measured experimentally on a buried pipe subjected to monotonic and cyclic thermal loads, hence reproducing the typical operating conditions of buried piping systems. Subsequently, a numerical model is developed using the finite element method, which is validated using the results obtained experimentally. Subsequently, this computational model was used to carry out a parametric study of the influence of the mechanical properties of the soil on the stress state of the system. Finally, from the results obtained experimentally and numerically, it is concluded that the most critical situation in terms of stresses takes place when the pipe is firstly placed into operation, i.e. in the first cycle of thermal load and the other variables studied have little impact. [ABSTRACT FROM AUTHOR]

Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study is the second part of a previous work recently published about the optimization a new facility for convective heat phytosanitary treatment system applying the heat of exhaust gases from a distillery boiler as energy source for the pallets thermal disinfection. In the mentioned work, a control volume element of 3D finite heat transfer mathematical model was applied and correlated with experimental data in order to study the optimal operational conditions of air temperature and retention time when block-type pallets are thermally treated. However, optimal conditions for the phytosanitary treatment of the stringer-type pallets (the second more used in world-wide trading operations) in the presented facility has not been assessed so far. This case study presents the development and application of a control volume element model of 2D finite heat transfer mathematical model to optimize the operational parameters for the phytosanitary treatment of stringer-class wood pallets. The optimization of treatment temperature and retention timeissimulated based on previous findings reported. Optimal conditions were found for stringer-type pallets withair temperature at 80°C and 95 min of treatment time. The thermal efficiency, the energy consumption index of per treated pallet at the studied conditions and the economic feasibility of the new treatment system is discussed. [ABSTRACT FROM AUTHOR]

Copyright of Revista Iberoamericana de Ingeniería Mecánica is the property of Editorial UNED and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper proposes a semi-analytical methodology that combines the asymptotic homogenization method (AHM) with the finite elements method (FEM) to solve boundary-value problems with rapidly oscillating coefficients. This approach is motivated by the convergence difficulties observed when this type of problem is addressed directly via FEM, whereas the AHM has shown to be efficacious for obtaining good generic approximations of the exact solution. Illustratively, this AHM-FEM methodology is developed for the mechanical equilibrium problem of a radially microperiodic orthotropic sphere under hydrostatic pressure, which allows its validation by comparing with the AHM analytical solution. Specifically, the effective coefficients and the homogenized and local problems are calculated via AHM, and then their analytical and FEM solutions are obtained. Finally, to validate the semianalytical methodology, the generic solutions are applied in an example and, from the obtained results, a comparison is made between the analytical AHM solution and the semi-analytical AHM-FEM solution. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Research & Development / Revista de Investigación & Desarrollo is the property of ECORFAN-Mexico S.C. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a study of magnetic flux density in a large synchronous large size machine when it is working as a generator. Finite elements software has been used to obtain the same physical and electrical characteristics of the real machine. From the results conveyed from the simulations, it is possible to find the optimal points where the magnetic flux sensors will be placed and to determine short-circuit faults in the rotor coils. The work results are also a reference to evaluate and compare the magnitudes taken by the sensors without creating short-circuits in the actual machine coil. Besides that, the proposed model based on finite elements can be used to make simulation tests of new kinds of sensors. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciencia y Poder Aéreo is the property of Escuela de Postgrados de la Fuerza Aerea Colombiana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In slope stability, an important factor to be considered is the presence of tension crack. Over the years, stability has been analyzed using the limit equilibrium analytical method and more recently with the use of numerical methods. In previous investigations, the location and/or the depth of the crack were previously set. In this investigation, using the finite element method, the behavior of the failure surface in soils was simulated, the properties of the materials were established, the geometric conditions (inclination and height of the slope) were assigned, evaluating their influence on the deformation by shear, in order to visualize the appearance of the fracture surface formed by the tensile crack, and in this way its location and depth were determined. It was shown that as the geometric conditions increase, the depth of the crack increases, the location distance decreases, as does the safety factor. Finally, it is concluded that tensile cracks occur in the case of the fine soils studied, that the geometric conditions are decisive in the location and depth of the tensile crack, as well as in the stability of the slope. [ABSTRACT FROM AUTHOR]

Currently, there are different options to increase the ultimate resistance of plate girders subjected to patch loading. Some of these alternatives include the use of closely spaced transverse stiffeners and the use of longitudinal stiffeners. Nevertheless, recent investigations have demonstrated that the resistance is also improved by using delta stiffeners, which are obtained by welding two plates between the web plate and the loaded flange. This paper aims at studying the elastic buckling behavior of slender plate girders designed following AASHTO norms with delta stiffeners subjected to patch loading. The research is carried out by means of eigenvalue analysis using the finite element method. A parametric study is performed to evaluate the influence of various geometrical parameters on the buckling coefficient of the girder. Finally, design recommendations are suggested based on the obtained results. [ABSTRACT FROM AUTHOR]

Copyright of Revista Iberoamericana de Ingeniería Mecánica is the property of Editorial UNED and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: Design the landing gear for a CESTOL type aircraft according to FAR 23 using: (i) the conceptual designs of the nose and main gear and (ii) evaluate the structural strength of the design by means of finite element analysis at a stage of landing. Materials and methods: The initial requirements for the theoretical development of a preliminary landing gear design are used as a case study. The aircraft's structure is taken as a base for the different design stages. This analysis is according to a static and level landing condition selected on each gear with a side and supplementary load. Additionally, calculations of geometric parameters and mechanical resistance with preselecting materials for the component analysis to determine and compare theoretical results with finite elements to evaluate the reliability of the design approach. Results and discussion: It is determined to move the main landing gear backward near the cargo area. That allows for better aircraft performance, placing the GC in front of the main gear and avoiding an overturn. However, this load percentage changes in proportion to the longitudinal stability criterion, where it generates an increase in the contribution to the mechanical stress in the structure of the gear. Conclusions: Results obtained about stability, controllability, and structural analysis are acceptable for the regulations of FAA Part 23 with standards associated with airworthiness, being corroborated with theoretical analysis and combined loads. [ABSTRACT FROM AUTHOR]

The increasing use of stainless steel in construction has led to the need of developing resistance models for structural elements made of this material. Unlike carbon steels, stainless steel alloys exhibit stress-strain curves with a pronounced strain hardening capacity and reasonable ductility that should be considered in the design. This difference in behavior makes the formulations used for carbon steel conservative when designing with stainless steel. Therefore, this paper presents a comparative analysis of resistance models for slender austenitic stainless-steel beams subject to concentrated loads. First, the failure mechanisms of stainless-steel beams are presented using a nonlinear finite element model. From this validated numerical model, a database obtained from a parametric analysis that covers a wide range of geometries is presented. Subsequently, this database is used to perform a comparison between various resistance models available in the literature. These models correspond to both international design codes and models obtained through machine learning. Finally, the numerical results show considerable improvement in the predicted ultimate resistances for slender stainless steel plate girders subjected to patch loading. [ABSTRACT FROM AUTHOR]

Copyright of Revista Sul-Americana de Engenharia Estrutural is the property of Revista Sul-Americana de Engenharia Estrutural and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, a model is developed and validated to numerically simulate normal and shear stresses exerted on the upper and lower faces of a rectangular and isotropic flat plate. The plate is supported on its four edges and the pressure is evenly distributed over its entire area. The general equation of plates using the double Fourier series method is applied to find analytical solutions. Numerical solutions are obtained by the finite element method (ANSYS 19.1 software). The model is validated statistically by comparing analytical and numerical solutions in a classic experiment that considered three pressure levels. The results show that there is no statistical significant difference between the two types of solutions. Therefore, it is concluded that the numerical simulation model is valid. [ABSTRACT FROM AUTHOR]

Welding is a process for joining elements commonly found at an industrial level where one of the most widely used types is the electric arc. For its correct application, variables such as type of electrode, amperage, voltage, travel speed, polarity, type of joint, among others, must be taken into account. In this work, the effect of travel speed was evaluated, which directly affects the mode of metal transfer and the morphology of the weld bead, therefore, it must be correctly defined in order to satisfactorily achieve the union of the materials. To determine its effect, the thermal profile was calculated on a plate using a finite element software. The speed values used were taken from specifications recommended by industrial suppliers of welding consumables. Furthermore, the simulation was performed for a butt joint, where it was assumed that the energy applied to the metal was uniform and constant over a circular area. [ABSTRACT FROM AUTHOR]

Currently, there is an interest within the scientific community in thin-film solar cells with a Kesterite (Cu2ZnSnS4) type absorber layer, since they report a theoretical efficiency greater than 32 %. The synthesis of Kesterites by evaporation has allowed for efficiencies at the laboratory level of 11.6 %. Although these are good results, the design of the evaporation chamber and the distribution of the electrodes is essential to control synthesis parameters and evaporate each precursor in the corresponding stage. This project seeks to design an evaporation chamber that can achieve a vacuum of 10-5 mbar, increase the deposition surface and avoid each precursor evaporation in a non-corresponding stage. This last objective was studied using Comsol multiphysics R. (licensed product) software, with the adequate disposition of metallic precursors (zinc, copper, and tin) determined by analyzing heat distribution. It was concluded that the lower the evaporation temperature of the precursor, the smaller the height of the copper electrode in the system. This is because, with a lower height the concentration of heat in the container is lower. [ABSTRACT FROM AUTHOR]

Introduction-- To enhance resistance to surface damage of materials due to mechanical actions, there have been created many procedures that allow its modification for different needs. This leads to researches conducted to determine the changes achieved in the properties due to said procedures. One method commonly applied is, for example, physical means of vapor deposition of thin films on a surface. In recent years, many rational and empirical models have been proposed for the study of said properties. One of these models is computational analysis, which allows determining a great number of properties while avoiding applying destructive tests, achieving to reduce experimental time spent and costs of manufacture of test tubes as well as the test itself. In this research, the hardness of a surface coating of Nichrome (NiCr 80-20) was determined with an indentation test modeled in Ansys, based on the finite elements' method. Objective-- To design a computational model that allows determining the surface hardness of material with coating Methodology-- The realization of this project was made with the software for engineering analysis ANSYS, and the model was made based on the Vickers Indentation Test regulation given by the ASTM, which states that the test must be done with a pyramidal diamond indenter, applying forces greater than 1 kgf. Results-- By running the respective numerical analysis for both the substrate and the coating, a surface hardness of 197.5073 VH was obtained for NiCr coating and surface hardness of 160.5809 VH for the S235 Steel (hardness of the interface). Conclusions-- It was determined that the model proposed is correct seeing as the values obtained for the Vickers' Hardness is approximately the same as the experimental value with an error of 0.7501% for the coating layer and 0.2605% for the substrate. It was also concluded that it is possible to use this same procedure to obtain the surface hardness for different materials than those treated in this article by using this tool. [ABSTRACT FROM AUTHOR]

This paper presents the calculation of residual stresses present in cylindrical pressure vessels subjected to weld repairs using the ASME PCC-2-2015 via numerical multiphysical thermal structural analysis using the finite element method. The methods of analysis of residual stress by numerical analysis are increasingly part of the dynamics of structural integrity in equipment such as pressure vessels, flanges, heat exchangers, in addition to observing the behavior of these stresses in the thermally affected areas due to welding processes. In welding repair, the sleeve is attached to the pressure vessel through two longitudinal welds and two transverse welds. The modeling of the pressure vessel, repair and welding were carried out according to the aforementioned standard. The welding parameters were adopted with what happens in practice, and with that the temperature distribution and heat flow were obtained. The objectives were to analyze the longitudinal, tangential and residual stresses in the regions of the weld, pressure vessel and repair during the welding period, and to verify the behavior of these stresses after the cooling period. This work shows that numerical analysis can be used efficiently and objectively in situations of control and knowledge of the structural integrity of equipment. [ABSTRACT FROM AUTHOR]

The advancement of technology in the field of civil construction has resulted in reinforced concrete structures of different solutions and increasingly slimmer, this requires more refined analyzes than the analytical methods provided for in technical standards. This research aimed to analyze the precision of results obtained by the application of the Finite Element Method in the numerical simulation of reinforced concrete beams. The influence of the choice of constitutive models and parameter adjustments on the results of the simulations was investigated, as well as the precision of some normative analytical equations in relation to the ultimate strength of the beam studied. For this purpose, the commercial software ATENA was used and the simulations were validated based on results obtained in tests of bending reinforced concrete beams. The constitutive models available in the software were tested and adjustments were made according to criteria provided for in the literature. The results of the numerical simulations, there was a good agreement with the experimental values and greater precision when compared to the design from the technical standards. It was also found that the accuracy of the simulation depends directly on the definition of the models and adjustments adopted in the modeling. [ABSTRACT FROM AUTHOR]

Copyright of Revista Facultad de Ingeniería - UPTC is the property of Universidad Pedagogica y Tecnologica de Colombia, Facultad de Ingenieria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article presents the implementation of a 3.5 kW resistive load bank applied to a four-stroke single-cylinder diesel engine test bench that operates with an alternator. With this experimental test bench, it is possible to perform mechanical, thermodynamic, and polluting emissions studies in compression-ignited or induced internal combustion engines. Applying the quantitative research methodology, the design of the electric charging system is carried out. Power control circuits and safety elements are designed for the load back. CAD software is used to design the structure and casing considering anthropometric measurements. Also, finite element analysis (FEA) is incorporated to verify the structural and thermal design criteria. he implementation of an electrical and instrumentation acceleration system for sensing power and torque in low-displacement engines showed a measurement error of less than 1%. Similarly, the FEA allowed to quantify the maximum efforts and guarantee a safety factor above 5. With the characterization of the implemented sensors, a correlation coefficient of up to 99.97% was achieved. The power measurement displayed an error lower than 3%, which leads to a high characterization capacity of any thermal machine with equal power or less than the designed one. [ABSTRACT FROM AUTHOR]

Ball mills are widely used in mining, agriculture, and cement industries. There is little information on the design of such equipment from a structural point of view. Some of the main causes of failure are fractures of its walls, due to the impact of steel balls on its internal surfaces. Normally, they are attenuated through the use of wet milling, which acts as a shock absorber and a casing that protects the internal surfaces of the mill. However, it should be noted that this casing is not used in small mills. To avoid failure, the thickness of the mill is overdesigned, increasing its cost. The design of small mills improves when considering the direct impact of the steel balls on the inner wall. This leads to the most critical condition of operation. In this work, the resulting stress field was evaluated following a couple of approaches: (I) the dynamic coefficient of impact loads was evaluated with the working energy principle and (II) a numerical analysis was performed with the Finite elements. The operating parameters were calculated with the BM-Crush program. The results showed that the cyclic stresses were close to the elastic limit. It was proposed to implement a rubber coating on the internal walls of the mill, and the stress field was reduced 8.3 times, for a thickness of the rubber of 3 mm. In this way, a potential fatigue failure is reduced. [ABSTRACT FROM AUTHOR]

Introduction: cervical pain is a symptom frequently found in clinical practice. One of the most frequent treatments for this condition, specifically for disc herniations, is discectomy with anterior cervical arthrodesis. The use of iliac crest graft is the habitual practice in Cuba, although it is gathered the antecedent of the use of other materials. Objective: to compare the behavior of grafts of bovine cortical, hydroxyapatite, polymethylmethacrylate, chromium-cobalt-molybdenum and tricortical autograft of iliac crest in the intervertebral space C6-C7 before the usual loads of cervical column. Methods: an experimental study was carried out by means of numerical simulation according to the finite element method, the different grafts were subjected to the axial loads recommended by the ASTM F2423-11e ISO 18192-1.2011 standards by means of the Free CAD 0.18 software in the C6-C7 space of an experimental model of the cervical spine. Results: the highest stresses supported by different grafts were: tricortical: 19190 kPa, xenograft: 13210 kPa, hydroxyapatite without porosity and with 50% porosity: 41500 kPa and 45100 kPa, respectively, polymethylmethacrylate: 4440 kPa and chrome-cobalt-molybdenum: 148470 kPa. Conclusions: all the grafts resisted the applied load except for the hydroxyapatite with 50% porosity. The tricortical graft described an adequate behavior. All caused stress in the adjacent vertebrae, mostly polymethylmethacrylate and chromiumcobalt- molybdenum. [ABSTRACT FROM AUTHOR]

Scaffolds are customized structures, whose designs influences cell growth for tissue repair. However, they are still under constant study to meet all the biological requirements. In this work, a methodology is proposed, and the behavior of various scaffold designs are numerically evaluated by using the finite elements method. Different geometries are evaluated by varying the material and pore size. Subsequently, after selecting the designs, the viability of the scaffolds in a scaffold-bone-plate assembly in two healing stages was evaluated. The initial, when there is no bone inside the scaffold, and the final repair, when the scaffold is full of bone material. For its evaluation, an equivalent scaffold geometry was proposed using basic homogenization techniques. It was observed that the bone within the Ti6Al4V scaffold significantly increases the mechanical properties of the area, and important areas of stress concentration can be generated. This highlights the convenience of the scaffold being biodegradable to avoid subsequent injuries to the patient, due to the difference in stiffness along the femur. In this evaluation, only two biocompatible materials were considered, such as titanium-aluminum-vanadium (Ti6Al4V) and polylactic acid (PLLA) (biodegradable). [ABSTRACT FROM AUTHOR]

Currently, finite element analysis techniques are used to reduce costs in the manufacturing process of sports prostheses. This study primarily focuses on the finite element analysis of a design for a transtibial prosthesis for a paralympic cyclist, integrating the biomechanics of an athlete with a double leg amputation below the knee with two prostheses categorized before the Union Cycling International (UCI) with a C-3 disability and the characteristics of the terrain and the dynamic model. The analysis employing finite elements aims to evaluate the static and dynamic behavior of the proposed design when subjected to competition in the track-cycling category. As a result of this analysis, mechanical aspects, such as static forces, buckling, frequency, fatigue, free fall, impact, and aerodynamics, can be evaluated to verify that the design of the proposed transtibial prosthesis meets an adequate aerodynamic profile and its mechanical characteristics are suitable to be used in a high-performance Paralympic cycling competition. [ABSTRACT FROM AUTHOR]

Asbestos cement is a material used in the production of lightweight roof tiles. It has been shown to be highly toxic and carcinogenic, which is why it is necessary to obtain new materials that do not present this problem, with equal or superior physical-mechanical characteristics, which can be used in the manufacture of roof tiles for different construction works. The objective of this research has been the mechanical characterization of the wavy type tile based on a polymeric matrix reinforced with fiberglass and the comparison of the resistive behavior through the Finite Element Method of light roofs built with this material and those made of asbestos cement, subjected to the wind loads. The critical crack values were obtained for the tiles made of both materials. The fiberglass reinforced tile presented more strength and a larger critical crack size. [ABSTRACT FROM AUTHOR]

Copyright of Revista Técnica Energía is the property of Centro Nacional de Control de Energia CENACE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ingeniería Solidaria is the property of Universidad Cooperativa de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dynamic forces and impact loads usually act on agricultural machines, causing breakages or failures. That is due to the nature of the impact loads, which are of short duration and decrease the capacity of the material of absorbing the deformation energy. The calculation methods that allow obtaining dynamic load coefficients require complex operations. In the present investigation, three methodologies for obtaining dynamic load coefficients were evaluated and compared: analytical method (MA), numerical simulation by the finite element method (MEF) and experimental method (Mexp). The coefficients of dynamic loads obtained from the MEF reached a relative difference that oscillated between 3.479 and 5.112%, based on the experimental results. For the analytical method, comparedto the experimental results, a relative difference between 21.820 and 27.201% was reached, which is higher than that obtained by the numerical simulation method. [ABSTRACT FROM AUTHOR]

Most of the soil-tillage tool interaction studies realized, both, experimental and numeric, have shown the influence of soil conditions (physical, mechanical and dynamic properties and type of soil), operation parameters of the tool (cutting deep, cutting speed, acceleration) and geometry in the magnitude of cutting forces. Those studies were carried out with little tool sliding to avoid distortion, which can cause convergence problems during the simulation. In this study, a three-dynamic (3D) lineal simulation model of soil narrow tool interaction was developed by the Finite Element Method (FEM) to analyze the tillage tool movement across a silt clay soil block (Ferrallitic). The extended Drucker-Prager elastoplastic constitutive relation model was used to model, which was accomplished using the Solid Works design software, 2014 version and its complement Simulation. For a better connection between soil and tillage tool surfaces, and to achieve good soil elements movement on the tool surface, contact elements and Coulomb theorem were used. The model predicted the soil movement, soil fault surfaces, stresses distribution, both, in soil and tillage tool, as well as the draft forces. The results of the simulation model were compared with models and experimental data of the other authors, and good estimates and trends were obtained. [ABSTRACT FROM AUTHOR]

A non-stationary model is shown, formed by the 1D hyperbolic differential equation, which is commonly used in practice for wave propagation of rivers and channels. As an upstream boundary condition, a function that depends on time has been taken, representing the variation of the water levels in the channel. Downstream, the wave equation with first derivatives in space and time is taken as the boundary condition, thus ensuring that there is no reflection of the wave in that boundary. Numerical algorithms obtained from the application of the Finite Differences Method and the Finite Element Method are formulated and the calculation algorithms are compared with an analytical solution showing good results. [ABSTRACT FROM AUTHOR]

Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Given the importance of knowing the mechanical response of the soil as one of the variables to be taken into account in the design of implements and machines capable of preserving the physical qualities of the soil, several constitutive models have been developed that represent the soil as a non-linear material elastic or elastoplastic. The objective of this paper was to analyze the current state of the constitutive models used in the modeling of agricultural soils in order to define which of them is the most adequate to simulate the mechanical response of agricultural soils with clay texture (Oxisol, Inceptisol and Vertisol). Constitutive models that are used in the simulation of the mechanical response of agricultural soils by means of the finite element method are analyzed critically, taking into account the properties and parameters of input, determination of these and their implementation in the softwares for simulation using the finite element method. Finally, it is concluded that the Drucker Prager Extended model as the most adequate to simulate the mechanical response of an Oxisol, prioritizing in this decision its simplicity, convenience when determining its parameters, accuracy in estimating the stress-strain relationship of the soil, and inclusion in most commercial software. [ABSTRACT FROM AUTHOR]

Given the importance of knowing the mechanical response of the soil as one of the variables to be taken into account in the design of implements and machines capable of preserving the physical qualities of the soil, several constitutive models have been developed that represent the soil as a non-linear material elastic or elastoplastic. The objective of this paper was to analyze the current state of the constitutive models used in the modeling of agricultural soils in order to define which of them is the most adequate to simulate the mechanical response of agricultural soils with clay texture (Oxisol, Inceptisol and Vertisol). Constitutive models that are used in the simulation of the mechanical response of agricultural soils by means of the finite element method are analyzed critically, taking into account the properties and parameters of input, determination of these and their implementation in the softwares for simulation using the finite element method. Finally, it is concluded that the Drucker Prager Extended model as the most adequate to simulate the mechanical response of an Oxisol, prioritizing in this decision its simplicity, convenience when determining its parameters, accuracy in estimating the stress-strain relationship of the soil, and inclusion in most commercial software. [ABSTRACT FROM AUTHOR]

This work presents the design of the chassis of a human powered vehicle (HPV) type recumbent of three wheels through design studies based on finite element analysis provided by Solidworks® tool. The methodology of design for manufacturing and assembly (DFMA) promoted by Bootrhoyd was implemented, for which, the design of a model built in 2014 by mechanical engineering students called VTHR-1 was used as a comparison element to determine the effects produced by this methodology in the redesign of the chassis. As a result, a safety factor of 1,6 and an estimated life of 4,293x10^5 cycles, in addition, a decrease of 69% in the complexity of the assembly of the power transmission system was estimated, a 32% reduction in manufacturing cost and a structure 19% lighter, which translates into an indispensable method when it comes to directing the project as an alternative transportation mean in the city of Monteria. [ABSTRACT FROM AUTHOR]

This study uses the application of finite element method in order to estimate the level of wear in elements of front loaders LeTourneau 1850, operating in mine Doña Ines de Collahuasi. Particularly the focus of the study using finite element method is on the wear parts that are considered "sacrifice parts" due to the extraction of mineral in the rock. In case the failure of one of these elements is not detected in advance, during a programmed inspection, or during operation, the damage may affect directly to the structure of the loader. As a consequence, its reparation will be much more expansive than changing previously the wear element for a new one. [ABSTRACT FROM AUTHOR]

This paper presents a numerical study on the elastic behavior of stiffened curved plates subjected to transverse loading. The analyses are performed by means of linear static analysis using finite element modelling. Firstly, flat plates under transverse loading (uniform and nonuniform-trapezoidal) are modelled to validate the computational model against analytical solutions available in the literature. Secondly, the behavior of unstiffened curves plates under transverse loading is analyzed. Then, the influence of both, transversal and longitudinal stiffening in controlling the out-of-plane displacements and stresses distribution of the curve plates is demonstrated. Finally, a case-study concerning the response of a hydroelectric power plant intake gates subjected to a hydrostatic head is further investigated. The results show that the increase in gate stiffness is reflected in smaller deformations implying a better performance and system integrity. [ABSTRACT FROM AUTHOR]

Landslide occurrence is associated with some conditioning factors and triggering landslide processes. This research contributes to quantify the influence of geomorphology as a conditioning factor in slope stability, via analysis based on a finite element method with an elastoplastic constitutive model. The analysis performs through a numerical simulation with nine three-dimensional slope models. The spatial variation of the stress tensor and its components were obtained by the invariants that reflect the influence of the geoform and flow regime in slope stability. Finally, the authors calculated an index potential failure that quantifies, in a unified manner, the influence of the confinement pressure and shear stress in the slope to determine a susceptibilty failure area. [ABSTRACT FROM AUTHOR]

A numerical method is formulated based on Finite Elements, Isogeometric Analysis and a Multiscale technique. Isogeometric Analysis, which uses B-Splines and NURBS as basis functions, is applied to evaluate its performance. The analyzed PDE is Poisson's Equation. The method starts with a coarse mesh which is refined to obtain each scale, considering every current scale mesh's element as a subdomain to the following scale. Local problems of each subdomain are solved independently, and the system is executed iteratively. Isogeometric analysis shows to have a better performance regarding approximation error and convergence in the iterative method that was derived here, which favorably influences computational cost. [ABSTRACT FROM AUTHOR]