ANSYS Environment Research Articles

Designing the Structure of and a Fabrication Process for a Corrective Insole in CAD/CAE/CAM Systems

This paper presents the results of our research into improving the design and fabrication quality of custom-molded corrective insoles by developing modern computer-aided modeling and programming methods that factor in changes in the mechanical properties of materials during use. This paper proposes a method for designing custom corrective insoles using the optimal insole structure and material. We used OrthoModel to design an insole model in a solid-body format and then exported it as an STL file. Then, using FreeCAD, we converted the STL file to a STEP file to better adapt the model for further use and analysis. Using the Ansys environment, we devised a finite element model for insole deformation and investigated the behavior exhibited by the material of the insole arch under different loads and combinations of EVA materials with varying hardness. The model yielded the stresses and deformations experienced by the insole arch during use, depending on the combination of the material and the geometry of the foot, and those stresses and deformations were experimentally verified. The calculated values for insole deformation served as input for programming the processing of the insole with a CNC machine. With a 3D insole model, it is possible to both fabricate the insole with a CNC machine and to print the insole with a 3D printer. The calculated cost price of fabricating custom-molded corrective insoles attests to the competitiveness of the proposed technique.

Automated fatigue strength assessment of arc-welded structures according to the Peak Stress Method

The Peak Stress Method (PSM) is an approximate, FE-oriented application of the notch stress intensity factor (NSIF) approach to fatigue design of welded joints. This approach is based on the singular linear elastic peak stresses calculated from coarse FE models. The PSM was calibrated by using 2D, four-node plane quadrilateral elements; 3D, eight-node brick elements and 3D, four-node or ten-node tetra elements. By adopting the averaged Strain Energy Density (SED) as a fatigue strength criterion, a design stress, the so-called equivalent peak stress, has been defined and adopted in conjunction with a reference design fatigue curve to estimate the fatigue life of welded structures. The equivalent peak stress has successfully been adopted to assess the fatigue strength of arc-welded joints made of either structural steels or aluminum alloys and subjected to axial, torsion or multiaxial fatigue loadings. In the present work, a subroutine, named ANSYS-PSM, has been developed in the post-processing environment of ANSYS® FE code to automate the PSM for 2D or 3D FE models. After having briefly recalled the theoretical background of the PSM and the procedure to apply it step by step, the paper presents the adopted programming languages and the workflow of the developed subroutine.

Fatigue crack growth of new FML composites for light ship buildings under predominant mode II loading condition

The use of light but strong materials is largely studied in various area of the shipbuilding, this because the need of reducing the weight, and especially the weight of all the structures above the main deck assume primary importance for the stability. Traditionally in fast boats like fast ferries, hydrofoils, patrol boats, the typical materials are Aluminum alloy or composites, both those materials have advantages and disadvantages, but the new development of technologies made possible to combine them, in order to have a new material, combining the advantages of both, in terms of fatigue resistance, firefighting characteristics. In this paper, predominant mode II fatigue delamination tests of fiber metal laminates made of alternating layers of 2024-T3 aluminum alloy sheets and unidirectional E-Glass/epoxy laminates are presented. Several experimental tests are carried out employing the End Notched Flexure fixture and a progressive damage model is used to simulate the damage accumulation in the aluminum-composite interface, in the localized area in front of the crack tip, where micro-cracking or void formation reduce the delamination strength during fatigue tests. In particular, the numerical model is based on the cohesive zone approach and on the analytical definition of a damage parameter, directly related to the fatigue crack growth rate da/dN. The numerical model, implemented in ANSYS environment, uses a fracture mechanics-based criterion in order to determine the damage propagation. In particular, the study has allowed to determine the damage model constants that are used for numerical verification of the experimental results.

Thermal and mechanical simulations of the lattice structures in the conformal cooling cavities for 3D printed injection molds

The recent developments in the additive manufacturing make easier and more affordable the fabrication of conformal cooling solutions for the injection molding processes compared to the traditional straight-drilled cooling structures. This paper presents four different conformal cooling cavities. Their thermal and mechanical performances are analyzed via computational solutions in the ANSYS environment. Each cavity is supported by lattice structures with unique geometric arrangements. Cooling time is considered as the main assessment criterion for the thermal analyses whereas the von Mises stress and fatigue life are the key criteria for the mechanical simulations. The results are compared with the reference geometry that is a traditional straight-drilled geometry and currently being operated in the real environment. It is seen that the cooling time is decreased in the range of 68.5–74.2%. However, only one of the cavity structures achieves close mechanical performance to the reference geometry; thus, the detailed discussions are also discussed for further studies.

Magnetorheological valves based on Herschel–Bulkley fluid model: modelling, magnetostatic analysis and geometric optimization

Magnetorheological (MR) fluids find wide application in various engineering applications. At the design stage of any MR devices, choosing a suitable rheological model for describing the flow behaviour is very critical. Since, the Herschel–Bulkley (H–B) is the most suitable model to describe the flow behaviour of MR fluids, the present study models the flow of MR fluid in the annular valve using the H–B model and does geometric optimization of the valve for three different commercially available MR fluids. The work discussed in the paper consist of three broader parts viz. (i) flow modelling, (ii) magnetostatic analysis and (iii) geometric optimization. In flow modelling, MR fluid flow is modelled using the H–B fluid model and validated by computational fluid dynamic analysis in ANSYS environment. Further, in magnetostatic analysis, for calculating the values of objective functions during the optimization process, magnetic flux density in the MR valve has been calculated using a polynomial model for the relative magnetic permeability for three different MR fluids, rather than conventionally choosing a constant value which is valid only for low ranges of current. The magnetostatic analysis has been validated through finite element modelling in ANSYS software package for different valve geometries. After defining the magnetization model for the chosen MR fluids and geometric design of the valve, variation of valve mass and performance indices such as damping force, dynamic range, inductive time constant and control energy, have been shown for all chosen fluids. In geometric optimization, the performance indices of the valve have been kept as objective functions which incorporate H–B fluid model for its definition. Such work has not been reported in the literature. Finally, a single-objective minimization problem has been formulated for the optimization with application-specific weight factors and solved using Genetic Algorithm in MATLAB® environment. The optimal results are then discussed and the best possible MR fluid has been suggested for the chosen applications.

Piezoceramic patches for energy harvesting and sensing purposes

This paper deals with a design, modelling, simulation, and test of vibrating mechanical cantilever with bonded piezoelectric patches for energy harvesting and sensing purposes. An experimental flexible structure was designed and piezoceramic patches were placed originally as energy harvesting devices. Furthermore, additional sensing functionality of piezoceramic patches is investigated in this paper. Such piezoceramic patches are integrated in the cantilever design and they could represent, for example, smart layers of an advanced aircraft structure. The design and position of the piezoceramic patches were analysed in the ANSYS environment. The finite element model was used to predict output voltage and power for varied vibration modes. This proposed design of the cantilever with piezoceramic patches was tested in laboratory conditions, and voltage response for varied mechanical excitation was measured and analysed for both energy harvesting and sensing purposes. Proposed paper will also present an example of practical usage of the tested design for impact detection. It could be mainly used in structural monitoring systems or health and usage systems in aircraft applications.

Determining the Self-Thermal Impedances of Power Transistors and Diodes of an IGBT Module Based on Its 3D Model

An approach to determine self-thermal impedances for construction of a thermal model of a power IGBT module based on the electrothermal analogy method has been considered. Unlike the conventional method, the suggested approach takes into account a change in the thermal resistances depending on the location of a power semiconductor device in the IGBT module. The thermal parameters to construct the model of a power module based on the electrothermal analogy were determined by the finite element method using a 3D model of the IGBT module in the ANSYS environment. The suggested approach is intended to improve the quality of prediction of temperature of chips in the power module under conditions close to operating ones.

Determining the most dangerous loading application point for asphalt-concrete layers on a rigid base

Operating conditions of asphalt-concrete layers on cement-concrete slabs differ significantly from other structural solutions. Practical road construction applies the insufficiently developed methods for calculating the strength of asphalt-concrete coating for rigid road beds since only separate strength criteria of the asphalt-concrete layer are standardized. Current calculation methods do not take into consideration the patterns in the stressed-strained state of an asphalt-concrete layer on cement-concrete slabs under various conditions for the application of load, such as the middle part of a slab, the edge of a slab, and the corner of a slab. The mismatch between the conditions for calculation and the actual stressed-deformed state of a structure predetermines the premature failure of an asphalt-concrete layer and, consequently, shortens the inter-maintenance period and leads to additional costs for unplanned repair.We have simulated the stressed-strained state of a road bed structure by using a finite-element method in the programming environment ANSYS for three variants of arrangement of transport loading, specifically in the center of a slab, at the edge of a slab, and in the corner of a slab.The paper provides, for the accepted variants of the transport loading, the derived values for the von Mises stresses, principal stresses, horizontal and maximal horizontal shear stresses. The stresses' values were determined at the surface of an asphalt-concrete layer, at a point of contact between an asphalt-concrete layer and a cement-concrete slab, and at a contact point between a cement-concrete slab and a base.We have compared the defined stresses in the layers of a road bed for different variants of the application of a transport loading, as well as compared the results obtained with known solutions.That has made it possible to establish that for the asphalt-concrete layer the arrangement of load in the corner of slab is the most dangerous, both in terms of shear stresses and the von Mises stresses. The stresses that occur when the load is applied at the corner of a slab are approximately 10 % higher than the stresses that occur when the load is applied at the edge of a slab, and are approximately 20 % higher than the stresses arising when the load is applied in the center of a slab.

An ejector for mixing a reagent with discharge water

The paper presents a research on ejectors used to mix discharge waters with flocculant or coagulant solutions intensifying the flotational discharge water treatment. Results of modelling using ANSYS environment are provided, visualizing the processes going on in the mixing chamber of the ejector as well as estimating parameters of those processes. The velocity gradient values were estimated, which is the main parameter with regard to the mixing process, and therefore characterizing the intensity of discharge water treatment. The dependency between the value of the velocity gradient and the velocity of the water entering the ejector was analyzed. It was shown that the gradient value changes nearly proportionally to the input velocity, and this dependency holds in all directions. The ration between the X component of the gradient and its Y and Z components amounts to approximately 2:1. That means, tarbulation does not significantly differ direction-wise, and the mixing conditions are favorable.

A Thermal Model of an IGBT Module Taking into Account Thermal Interconnections between Chips

An approach to development of the thermal model of an IGBT module based on the method of electro-thermal analogy is considered. Unlike traditional one-dimensional thermal models, a new model is supplemented with thermal interrelations between chips. The parameters of thermal interrelations were determined using studying the 3D-model of the power module in the ANSYS environment. The proposed model is intended to improve the quality of predicting the temperature of power module chips due to taking into account the thermal mutual influence of the chips.

Comparing different bar materials for mandibular implant-supported overdenture: Finite-element analysis

This study was conducted aiming to optimize the selection of bar material that can minimize stresses on mandibular bone. One finite-element model was created under ANSYS environment to evaluate the use of different materials as a bar-manufacturing material in mandibular implant-supported overdenture (OD). Model components were created on engineering computer-aided design software and then assembled under the finite-element package. A force of 200 N was unilaterally and vertically applied on the left second premolar area. Within these study conditions, the polyether ether ketone bar produced the lowest Von Mises stress on OD and the maximum value of deformation. Stainless steel bar produced the maximum OD total deformation. Cortical and spongy bones are not sensitive to the bar material. Increasing bar material stiffness increases Von Mises stresses in the bar itself and reduces its total deformation, in what is called overconstrained system.

Comparing different bar materials for mandibular implant-supported overdenture: Finite-element analysis

<br><b>Aim:</b> This study was conducted aiming to optimize the selection of bar material that can minimize stresses on mandibular bone. <b>Subjects and Methods:</b> One finite-element model was created under ANSYS environment to evaluate the use of different materials as a bar-manufacturing material in mandibular implant-supported overdenture (OD). Model components were created on engineering computer-aided design software and then assembled under the finite-element package. A force of 200 N was unilaterally and vertically applied on the left second premolar area. <b>Results:</b> Within these study conditions, the polyether ether ketone bar produced the lowest Von Mises stress on OD and the maximum value of deformation. Stainless steel bar produced the maximum OD total deformation. <b>Conclusions:</b> Cortical and spongy bones are not sensitive to the bar material. Increasing bar material stiffness increases Von Mises stresses in the bar itself and reduces its total deformation, in what is called overconstrained system.<br>

Analysis of the special features of hydrodynamics in the boundary layer of the nozzle of the developed surface

The object of research is the hydrodynamics of the boundary layer of the nozzle element of the proposed design. In the course of the study, computer simulation methods were used in the ANSYS environment, in particular the CFX block, which includes a set of physical, mathematical and numerical methods designed to calculate the characteristics of streaming processes. The analysis of the influence of the fluid velocity in the packed bed bioreactor on the magnitude of the hydraulic resistance for the following values of the fluid velocity: 0.1 m/s; 1 m/s; 2 m/s. The obtained data almost repeat the value of experimental studies, confirms the correctness of the construction of a computer model. A simulation of the hydrodynamics of a single nozzle of the proposed design for a longitudinal and transverse flow of fluid is done. Changes in the hydraulic resistance during transverse flow around the nozzle are insignificant, the maximum value lies within 101.3 kPa, for longitudinal washing the value of the pressure differential lies in the range from 98.96 to 102.7 kPa. Diagrams of the distribution of fields and velocity vectors in the boundary layer of the nozzle are obtained. When transversal washing of the nozzle, the magnitude of the velocities is in the range from 0 to 1.511 m/s, for longitudinal washer it ranges from 0 to 1.968 m/s. The distribution of the shear rate in the boundary layer is established, for the transverse washing of the nozzle, the magnitude of the shear flow rate ranges from 3.1 to 4.27·103 s-1, for a longitudinal washing of the nozzle, this indicator ranges from 5.6 to 1.25·104 s-1. Through the use of the proposed nozzle, it is possible to obtain large specific surface areas for the immobilization of microorganisms, provided that the critical parameters of the cultivation process are in accordance with permissible maximum deviations. Compared with the methods of determining the optimal parameters experimentally, a computer model is proposed that provides the following advantages: a significant reduction in the material costs of introducing a new nozzle design and a quick optimization of the process parameters when the initial data changes.

The dilemma of functional therapy: the new EFA to do or not to do?

ObjectivesThis finite element analysis was conducted to study the effects produced by a new fixed functional appliance (EFA; Elhiny functional appliance) and hence predict its clinical effectiveness.Materials/methodsUnder ANSYS environment, a simplified 2D finite element model was prepared for this study. The models simulated a clinical situation where the mandible was positioned forward via a new fixed functional appliance design. The models’ components were created on a commercial CAD/CAM package then imported to finite element software. Pushing load of 2 N was applied along the appliance longitudinal direction.ResultsThe mandible showed downward and forward deformation in the X and Y directions with the highest deformation at the symphysis and lower border with a total deformation of 80 μm. There was little deformation in the maxilla. The highest strain results were at the condyle, both compressive and tensile in the X and Y directions with a total of 1520 micro strain behind the condyle. The strain in the mandibular tooth bearing area was around zero and in the maxillary tooth bearing area ranged from − 9 to 16.6 micro strain.ConclusionsWithin the limitations of this finite element analysis, it could be predicted that the new appliance (EFA) produces pure functional skeletal results with absolutely no dentoalveolar effects, which provides the opportunity for observing significant skeletal changes.

Strain Analysis of Supporting Profile Vulcanizing Press

The article is devoted research of process equipment in the simulation of the stress-strain state of load-bearing elements in the environment of ANSYS. The obtained results are consistent with the data of preliminary calculations and confirm the performance of device. The device for connecting the ends of a conveyor fabric-rubber belt by a vulcanization method is a set of ten segments. At the stage of preliminary calculation stress-strain properties of supporting profiles vulcanizing press were determined by using SCAD software. Point load of hydraulic cylinders is transmitted on profiles in accordance with terms of reference. Strength calculation supporting profile in ANSYS software was carried out using Finite Element Method. The segment of the device under consideration is symmetrical with respect to two planes. Therefore, it was decided to simplify the calculation model using the capabilities of the ANSYS software, namely using the "Symmetry" modifier. This simplification reduces the requirements for computing power of the computer, which, in turn, allows to build a better mesh. Mesh is constructed mainly from eight-node volumetric elements of regular shape. Analysis of the supporting profile in ANSYS software confirmed the results of preliminary settlements. There are stresses in the dangerous sections of the upper profile exceeding the yield point. Despite this, during unloading, residual deformations in the profile are absent, since for the most part of the profile length in the sections there is no limiting state, that is, the stresses do not reach the yield point.

Finite element analysis of the dental crown: a case study of alumina based incisor

The purpose of this study was to evaluate the stress distribution on newly developed alumina based dental crown (incisor) for understanding its biomechanical effects by Finite Element Analysis (FEA). Alumina based dental crown was fabricated through green machining of machinable alumina cylindrical compacts by Computer Numerical Control (CNC) followed by sintering at 1550°C. Alumina crown (Incisor) was scanned by using 3D laser scanner and modified subsequently before assembled in a 3D finite element model. The 3D model was constructed and analyzed under ANSYS environment. The model developed high stress values at the upper frontal and basal region. The large stress concentration factors and narrow profile of the upper region and the arrested base are believed to have been responsible for the high stress values. Since the stresses were lower than the compressive strength of the material, the crown is expected to withstand real-time static loading.

Optimization of the Straight-Through Labyrinth Seal With a Smooth Land

This paper presents the methodology and results of the optimization of a straight-through labyrinth seal with two inclined fins against smooth-land. The optimization was performed using commercial tools implemented in the ANSYS environment, such as goal-driven optimization. The response surfaces were created based on Latin hypercube samples found from computational fluid dynamics (CFD) calculations. The CFD solver, using a steady-state scheme with the k–ω shear stress transport (SST) turbulence model, was applied. A screening algorithm was used to find the best candidates on the response surfaces. The objective function adopted in the labyrinth seal optimization was the minimization of the discharge coefficient value. A wide range of parameters of the fins position and shape were taken into account, with physically justified degrees-of-freedom. The optimization results were supported by the results of an in-house experiment performed on a stationary, linear test rig. The test rig was fed by a high-capacity vacuum air blower with high-precision hot-wire anemometry mass flow evaluation. The reductions in the leakage significantly exceed the uncertainties of the CFD model and the test rig accuracy. The factors that had the most substantial impact on the leakage reduction were the location, inclination, and thickness of the fins. The experimental results were compared with the calculations and the optimization effects, highlighting some tendencies in the labyrinth seal flow behavior. Good agreement was obtained between the optimization results and the experimental data, proving that the presented methodology is sufficient for the labyrinth seal optimization.

Simulation fabrication and characterization of micro-cantilever array based ozone sensor

Abstract Cantilever plays a significant role in sensing of gases with miniaturing technology replacing conventional sensors. In this paper, the micro-cantilever array was simulated using COMSOL Multiphysics 4.2 and Ansys environment to analyze the microcantilever array based on resonant frequency mechanism. From the simulation results, the fabrication of the micro-cantilever array on SOI wafer with gold layers coated on the surface was done. The microstructure of the fabricated microcantilever array was characterized using SEM and AFM. The fabricated cantilever array was tested by Laser Doppler Vibrometer on exposing it to ozone gas to find the resonant frequency of each cantilever in a micro-cantilver array. From the simulation and fabrication results, it was found that these results were well-matched and the design is best suited for sensing the ozone gas efficiently using micro-cantilever array. Of the three micro-cantilevers in a micro-cantilever array used in this investigation, cantilever-C has good sensitivity towards detecting ozone gas efficiently, due to the high structural stability.

Inter Chamber Leakages in Orbit Motors- Estimation by Modeling and Simulation in FEM and Fluent® Environment

An analysis is carried out to predict inter-chamber leakage flows through the two transition active contacts, which separate the high pressure chambers from the adjacent low pressure chambers, in the cycloidal class toothed starring of ORBIT® motors. Among geometrically form closed contacts which separates chambers from each other, few active contacts support high reaction loads during the process of transmitting torque in such unique LSHT hydrostatic units. Contact deformations in those contacts generate gaps in the other contacts for a partial period of time. High inter-chamber leakages occur through such gaps at transition active contacts. In an attempt to visualize the characteristics of such leakages, which contribute towards the poorer leakage characteristics of such machines, detail mapping i.e., magnitudes, rotational position etc., of such gaps of a commercially available unit, are carried out. For estimating gaps FEM technique is used. The FEM results have very good agreement with the results predicted earlier using trial method. Such gaps are difficult to measure as the contact positions are inaccessible to equip any conventional measuring instrument. The characteristics of leakage flows through such gaps are then established by CFD analysis using Fluent® in Ansys environment.

Development of a Touch Probing System for Gaging the Compressor Blades of the GTE

The article describes the touch probing system with the strain gage as the main measuring element. The device has small geometric dimensions and it was developed to measure the gas turbine engine compressor blades. To select the optimum configuration of the probing system, mathematical models of two principal configurations were developed. Simulation modeling of the force of the measured surface impact on the measuring tip was carried out in the Ansys environment for these assemblies. On the basis of practical experiments, the diagram of the deviation of the probe on the resistance of the strain gage was constructed. Reference element were measured to determine the accuracy of the designed touch probing system.